[
{
"path": ".classpath",
"content": "\n\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\n"
},
{
"path": ".gitignore",
"content": "bin/\n"
},
{
"path": ".gitmodules",
"content": "[submodule \"php\"]\n\tpath = php\n\turl = https://github.com/careercup/CtCI-6th-Edition-php.git\n[submodule \"cpp\"]\n\tpath = cpp\n\turl = https://github.com/careercup/CtCI-6th-Edition-cpp.git\n[submodule \"Clojure\"]\n\tpath = Clojure\n\turl = https://github.com/careercup/CtCI-6th-Edition-Clojure.git\n[submodule \"Groovy\"]\n\tpath = Groovy\n\turl = https://github.com/careercup/CtCI-6th-Edition-Groovy.git\n[submodule \"Python\"]\n\tpath = Python\n\turl = https://github.com/careercup/CtCI-6th-Edition-Python.git\n[submodule \"Swift\"]\n\tpath = Swift\n\turl = https://github.com/careercup/CtCI-6th-Edition-Swift.git\n[submodule \"Haskell\"]\n\tpath = Haskell\n\turl = https://github.com/careercup/CtCI-6th-Edition-Haskell.git\n[submodule \"JavaScript\"]\n\tpath = JavaScript\n\turl = https://github.com/careercup/CtCI-6th-Edition-JavaScript.git\n[submodule \"JavaScript-ES2015\"]\n\tpath = JavaScript-ES2015\n\turl = https://github.com/careercup/CtCI-6th-Edition-JavaScript-ES2015.git\n[submodule \"Go\"]\n\tpath = Go\n\turl = https://github.com/careercup/CtCI-6th-Edition-Go.git\n[submodule \"CtCI-6th-Edition-CSharp\"]\n\tpath = CSharp\n\turl = https://github.com/careercup/CtCI-6th-Edition-CSharp.git\n[submodule \"c\"]\n\tpath = c\n\turl = https://github.com/careercup/CtCI-6th-Edition-C.git\n[submodule \"Objective-C\"]\n\tpath = Objective-C\n\turl = https://github.com/careercup/CtCI-6th-Edition-Objective-C.git\n[submodule \"Julia\"]\n\tpath = Julia\n\turl = https://github.com/careercup/CtCI-6th-Edition-Julia.git\n[submodule \"Ruby\"]\n\tpath = Ruby\n\turl = https://github.com/careercup/CtCI-6th-Edition-Ruby.git\n[submodule \"Kotlin\"]\n\tpath = Kotlin\n\turl = https://github.com/careercup/CtCI-6th-Edition-Kotlin.git\n"
},
{
"path": ".project",
"content": "\n\n\tCtCIv6\n\t\n\t\n\t\n\t\n\t\t\n\t\t\torg.eclipse.jdt.core.javabuilder\n\t\t\t\n\t\t\t\n\t\t\n\t\n\t\n\t\torg.eclipse.jdt.core.javanature\n\t\n\n"
},
{
"path": "Java/Big O/Example_16/Example.java",
"content": "package Example_16;\n\npublic class Example {\n\n\tpublic static int powersOf2(int n) {\n\t\tif (n < 1) {\n\t\t\treturn 0;\n\t\t} else if (n == 1) {\n\t\t\tSystem.out.println(1);\n\t\t\treturn 1;\n\t\t} else {\n\t\t\tint prev = powersOf2(n / 2);\n\t\t\tint curr = prev * 2;\n\t\t\tSystem.out.println(curr);\n\t\t\treturn curr;\n\t\t}\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tpowersOf2(4);\n\t}\n\n}\n"
},
{
"path": "Java/Big O/QVI_11_Print_Sorted_Strings/Question.java",
"content": "package QVI_11_Print_Sorted_Strings;\n\n\npublic class Question {\n\n\tpublic static int numChars = 26;\n\t\n\tpublic static void printSortedStrings(int remaining) {\n\t\tprintSortedStrings(remaining, \"\");\n\t}\n\t\n\tpublic static void printSortedStrings(int remaining, String prefix) {\n\t\tif (remaining == 0) {\n\t\t\tif (isInOrder(prefix)) {\n\t\t\t\tSystem.out.println(prefix);\n\t\t\t}\n\t\t} else {\n\t\t\tfor (int i = 0; i < numChars; i++) {\n\t\t\t\tchar c = ithLetter(i);\n\t\t\t\tprintSortedStrings(remaining - 1, prefix + c);\n\t\t\t}\n\t\t}\n\t}\n\t\n\tpublic static boolean isInOrder(String s) {\n\t\tboolean isInOrder = true;\n\t\tfor (int i = 1; i < s.length(); i++) {\n\t\t\tint prev = ithLetter(s.charAt(i - 1));\n\t\t\tint curr = ithLetter(s.charAt(i));\n\t\t\tif (prev > curr) {\n\t\t\t\tisInOrder = false;\n\t\t\t}\n\t\t}\n\t\treturn isInOrder;\n\t}\n\t\n\tpublic static char ithLetter(int i) {\n\t\treturn (char) (((int) 'a') + i);\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tprintSortedStrings(5);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_01_Is_Unique/QuestionA.java",
"content": "package Q1_01_Is_Unique;\r\n\r\npublic class QuestionA {\r\n\tpublic static boolean isUniqueChars(String str) {\r\n\t\tif (str.length() > 128) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tboolean[] char_set = new boolean[128];\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tint val = str.charAt(i);\r\n\t\t\tif (char_set[val]) return false;\r\n\t\t\tchar_set[val] = true;\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString[] words = {\"abcde\", \"hello\", \"apple\", \"kite\", \"padle\"};\r\n\t\tfor (String word : words) {\r\n\t\t\tSystem.out.println(word + \": \" + isUniqueChars(word));\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_01_Is_Unique/QuestionB.java",
"content": "package Q1_01_Is_Unique;\r\n\r\npublic class QuestionB {\r\n\r\n\t/* Assumes only letters a through z. */\r\n\tpublic static boolean isUniqueChars(String str) {\r\n\t\tif (str.length() > 26) { // Only 26 characters\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tint checker = 0;\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tint val = str.charAt(i) - 'a';\r\n\t\t\tif ((checker & (1 << val)) > 0) return false;\r\n\t\t\tchecker |= (1 << val);\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString[] words = {\"abcde\", \"hello\", \"apple\", \"kite\", \"padle\"};\r\n\t\tfor (String word : words) {\r\n\t\t\tSystem.out.println(word + \": \" + isUniqueChars(word));\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_01_Is_Unique/Tester.java",
"content": "package Q1_01_Is_Unique;\n\npublic class Tester {\n\t\n\tpublic static void main(String[] args) {\n\t\tString[] words = {\"abcde\", \"hello\", \"apple\", \"kite\", \"padle\"};\n\t\tfor (String word : words) {\n\t\t\tboolean wordA = QuestionA.isUniqueChars(word);\n\t\t\tboolean wordB = QuestionB.isUniqueChars(word);\n\t\t\tif (wordA == wordB) {\n\t\t\t\tSystem.out.println(word + \": \" + wordA);\n\t\t\t} else {\n\t\t\t\tSystem.out.println(word + \": \" + wordA + \" vs \" + wordB);\n\t\t\t}\n\t\t}\n\t}\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_02_Check_Permutation/QuestionA.java",
"content": "package Q1_02_Check_Permutation;\r\n\r\npublic class QuestionA {\t\r\n\tpublic static String sort(String s) {\r\n\t\tchar[] content = s.toCharArray();\r\n\t\tjava.util.Arrays.sort(content);\r\n\t\treturn new String(content);\r\n\t}\r\n\t\r\n\tpublic static boolean permutation(String s, String t) {\r\n\t\treturn sort(s).equals(sort(t));\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString[][] pairs = {{\"apple\", \"papel\"}, {\"carrot\", \"tarroc\"}, {\"hello\", \"llloh\"}};\r\n\t\tfor (String[] pair : pairs) {\r\n\t\t\tString word1 = pair[0];\r\n\t\t\tString word2 = pair[1];\r\n\t\t\tboolean anagram = permutation(word1, word2);\r\n\t\t\tSystem.out.println(word1 + \", \" + word2 + \": \" + anagram);\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_02_Check_Permutation/QuestionB.java",
"content": "package Q1_02_Check_Permutation;\r\n\r\npublic class QuestionB {\t\r\n\tpublic static boolean permutation(String s, String t) {\r\n\t\tif (s.length() != t.length()) return false; // Permutations must be same length\r\n\t\t\r\n\t\tint[] letters = new int[128]; // Assumption: ASCII\r\n\t\tfor (int i = 0; i < s.length(); i++) {\r\n\t\t\tletters[s.charAt(i)]++;\r\n\t\t}\r\n\t\t \r\n\t\tfor (int i = 0; i < t.length(); i++) {\r\n\t\t\tletters[t.charAt(i)]--;\r\n\t\t if (letters[t.charAt(i)] < 0) {\r\n\t\t \treturn false;\r\n\t\t }\r\n\t\t}\r\n\t\t \r\n\t\treturn true; // letters array has no negative values, and therefore no positive values either\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString[][] pairs = {{\"apple\", \"papel\"}, {\"carrot\", \"tarroc\"}, {\"hello\", \"llloh\"}};\r\n\t\tfor (String[] pair : pairs) {\r\n\t\t\tString word1 = pair[0];\r\n\t\t\tString word2 = pair[1];\r\n\t\t\tboolean anagram = permutation(word1, word2);\r\n\t\t\tSystem.out.println(word1 + \", \" + word2 + \": \" + anagram);\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_03_URLify/Question.java",
"content": "package Q1_03_URLify;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\t// Assume string has sufficient free space at the end\r\n\tpublic static void replaceSpaces(char[] str, int trueLength) {\r\n\t\tint spaceCount = 0, index, i = 0;\r\n\t\tfor (i = 0; i < trueLength; i++) {\r\n\t\t\tif (str[i] == ' ') {\r\n\t\t\t\tspaceCount++;\r\n\t\t\t}\r\n\t\t}\r\n\t\tindex = trueLength + spaceCount * 2;\r\n\t\tif (trueLength < str.length) str[trueLength] = '\\0';\r\n\t\tfor (i = trueLength - 1; i >= 0; i--) {\r\n\t\t\tif (str[i] == ' ') {\r\n\t\t\t\tstr[index - 1] = '0';\r\n\t\t\t\tstr[index - 2] = '2';\r\n\t\t\t\tstr[index - 3] = '%';\r\n\t\t\t\tindex = index - 3;\r\n\t\t\t} else {\r\n\t\t\t\tstr[index - 1] = str[i];\r\n\t\t\t\tindex--;\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static int findLastCharacter(char[] str) {\r\n\t\tfor (int i = str.length - 1; i >= 0; i--) {\r\n\t\t\tif (str[i] != ' ') {\r\n\t\t\t\treturn i;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn -1;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = \"Mr John Smith \";\r\n\t\tchar[] arr = str.toCharArray();\r\n\t\tint trueLength = findLastCharacter(arr) + 1;\r\n\t\treplaceSpaces(arr, trueLength);\t\r\n\t\tSystem.out.println(\"\\\"\" + AssortedMethods.charArrayToString(arr) + \"\\\"\");\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_04_Palindrome_Permutation/Common.java",
"content": "package Q1_04_Palindrome_Permutation;\n\npublic class Common {\n\n\tpublic static int getCharNumber(Character c) {\n\t\tint a = Character.getNumericValue('a');\n\t\tint z = Character.getNumericValue('z');\n\t\t\n\t\tint val = Character.getNumericValue(c);\n\t\tif (a <= val && val <= z) {\n\t\t\treturn val - a;\n\t\t}\n\t\treturn -1;\n\t}\n\t\n\tpublic static int[] buildCharFrequencyTable(String phrase) {\n\t\tint[] table = new int[Character.getNumericValue('z') - Character.getNumericValue('a') + 1];\n\t\tfor (char c : phrase.toCharArray()) {\n\t\t\tint x = getCharNumber(c);\n\t\t\tif (x != -1) {\n\t\t\t\ttable[x]++;\n\t\t\t}\n\t\t}\n\t\treturn table;\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_04_Palindrome_Permutation/QuestionA.java",
"content": "package Q1_04_Palindrome_Permutation;\n\npublic class QuestionA {\t\n\tpublic static boolean checkMaxOneOdd(int[] table) {\n\t\tboolean foundOdd = false;\n\t\tfor (int count : table) {\n\t\t\tif (count % 2 == 1) {\n\t\t\t\tif (foundOdd) {\n\t\t\t\t\treturn false;\n\t\t\t\t}\n\t\t\t\tfoundOdd = true;\n\t\t\t}\n\t\t}\n\t\treturn true;\n\t}\n\t\n\tpublic static boolean isPermutationOfPalindrome(String phrase) {\n\t\tint[] table = Common.buildCharFrequencyTable(phrase);\n\t\treturn checkMaxOneOdd(table);\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString pali = \"Rats live on no evil star\";\n\t\tSystem.out.println(isPermutationOfPalindrome(pali));\n\t}\n\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_04_Palindrome_Permutation/QuestionB.java",
"content": "package Q1_04_Palindrome_Permutation;\n\npublic class QuestionB {\t\n\n\tpublic static boolean isPermutationOfPalindrome(String phrase) {\n\t\tint countOdd = 0;\n\t\tint[] table = new int[Character.getNumericValue('z') - Character.getNumericValue('a') + 1];\n\t\tfor (char c : phrase.toCharArray()) {\n\t\t\tint x = Common.getCharNumber(c);\n\t\t\tif (x != -1) {\n\t\t\t\ttable[x]++;\n\n\t\t\t\tif (table[x] % 2 == 1) {\n\t\t\t\t\tcountOdd++;\n\t\t\t\t} else {\n\t\t\t\t\tcountOdd--;\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t\treturn countOdd <= 1;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString pali = \"Ratzs live on no evil starz\";\n\t\tSystem.out.println(isPermutationOfPalindrome(pali));\n\t\tString pali2 = \"Zeus was deified, saw Suez\";\n\t\tSystem.out.println(isPermutationOfPalindrome(pali2));\n\t}\n\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_04_Palindrome_Permutation/QuestionC.java",
"content": "package Q1_04_Palindrome_Permutation;\n\npublic class QuestionC {\n\t/* Toggle the ith bit in the integer. */\n\tpublic static int toggle(int bitVector, int index) {\n\t\tif (index < 0) return bitVector;\n\t\t\n\t\tint mask = 1 << index;\n\t\tif ((bitVector & mask) == 0) {\n\t\t\tbitVector |= mask;\n\t\t} else {\n\t\t\tbitVector &= ~mask;\n\t\t}\n\t\treturn bitVector;\n\t}\n\t\n\t/* Create bit vector for string. For each letter with value i,\n\t * toggle the ith bit. */\n\tpublic static int createBitVector(String phrase) {\n\t\tint bitVector = 0;\n\t\tfor (char c : phrase.toCharArray()) {\n\t\t\tint x = Common.getCharNumber(c);\n\t\t\tbitVector = toggle(bitVector, x);\n\t\t}\n\t\treturn bitVector;\n\t}\n\t\n\t/* Check that at most one bit is set by subtracting one from the \n\t * integer and ANDing it with the original integer. */\n\tpublic static boolean checkAtMostOneBitSet(int bitVector) {\n\t\treturn (bitVector & (bitVector - 1)) == 0;\n\t}\n\t\n\tpublic static boolean isPermutationOfPalindrome(String phrase) {\n\t\tint bitVector = createBitVector(phrase);\n\t\treturn checkAtMostOneBitSet(bitVector);\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString pali = \"Rats live on no evil star\";\n\t\tSystem.out.println(isPermutationOfPalindrome(pali));\n\t}\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_04_Palindrome_Permutation/Tester.java",
"content": "package Q1_04_Palindrome_Permutation;\n\npublic class Tester {\n\n\t\n\tpublic static void main(String[] args) {\n\t\tString[] strings = {\"Rats live on no evil star\",\n\t\t\t\t\t\t\t\"A man, a plan, a canal, panama\",\n\t\t\t\t\t\t\t\"Lleve\",\n\t\t\t\t\t\t\t\"Tacotac\",\n\t\t\t\t\t\t\t\"asda\"};\n\t\tfor (String s : strings) {\n\t\t\tboolean a = QuestionA.isPermutationOfPalindrome(s);\n\t\t\tboolean b = QuestionB.isPermutationOfPalindrome(s);\n\t\t\tboolean c = QuestionC.isPermutationOfPalindrome(s);\n\t\t\tSystem.out.println(s);\n\t\t\tif (a == b && b == c) {\n\t\t\t\tSystem.out.println(\"Agree: \" + a);\n\t\t\t} else {\n\t\t\t\tSystem.out.println(\"Disagree: \" + a + \", \" + b + \", \" + c);\n\t\t\t}\n\t\t\tSystem.out.println();\n\t\t}\n\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_05_One_Away/QuestionA.java",
"content": "package Q1_05_One_Away;\n\npublic class QuestionA {\n\n\tpublic static boolean oneEditReplace(String s1, String s2) {\n\t\tboolean foundDifference = false;\n\t\tfor (int i = 0; i < s1.length(); i++) {\n\t\t\tif (s1.charAt(i) != s2.charAt(i)) {\n\t\t\t\tif (foundDifference) {\n\t\t\t\t\treturn false;\n\t\t\t\t}\n\t\t\t\t\n\t\t\t\tfoundDifference = true;\n\t\t\t}\n\t\t}\n\t\treturn true;\n\t}\n\t\n\t/* Check if you can insert a character into s1 to make s2. */\n\tpublic static boolean oneEditInsert(String s1, String s2) {\n\t\tint index1 = 0;\n\t\tint index2 = 0;\n\t\twhile (index2 < s2.length() && index1 < s1.length()) {\n\t\t\tif (s1.charAt(index1) != s2.charAt(index2)) {\n\t\t\t\tif (index1 != index2) {\n\t\t\t\t\treturn false;\n\t\t\t\t}\t\t\n\t\t\t\tindex2++;\n\t\t\t} else {\n\t\t\t\tindex1++;\n\t\t\t\tindex2++;\n\t\t\t}\n\t\t}\n\t\treturn true;\n\t}\t\n\t\n\tpublic static boolean oneEditAway(String first, String second) {\n\t\tif (first.length() == second.length()) {\n\t\t\treturn oneEditReplace(first, second);\n\t\t} else if (first.length() + 1 == second.length()) {\n\t\t\treturn oneEditInsert(first, second);\n\t\t} else if (first.length() - 1 == second.length()) {\n\t\t\treturn oneEditInsert(second, first);\n\t\t} \n\t\treturn false;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString a = \"pse\";\n\t\tString b = \"pale\";\n\t\tboolean isOneEdit = oneEditAway(a, b);\n\t\tSystem.out.println(a + \", \" + b + \": \" + isOneEdit);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_05_One_Away/QuestionB.java",
"content": "package Q1_05_One_Away;\n\npublic class QuestionB {\t\npublic static boolean oneEditAway(String first, String second) {\n\t\t/* Length checks. */\n\t\tif (Math.abs(first.length() - second.length()) > 1) {\n\t\t\treturn false;\n\t\t}\n\t\t\n\t\t/* Get shorter and longer string.*/\n\t\tString s1 = first.length() < second.length() ? first : second;\n\t\tString s2 = first.length() < second.length() ? second : first;\n\n\t\tint index1 = 0;\n\t\tint index2 = 0;\n\t\tboolean foundDifference = false;\n\t\twhile (index2 < s2.length() && index1 < s1.length()) {\n\t\t\tif (s1.charAt(index1) != s2.charAt(index2)) {\n\t\t\t\t/* Ensure that this is the first difference found.*/\n\t\t\t\tif (foundDifference) return false;\n\t\t\t\tfoundDifference = true;\n\t\t\t\tif (s1.length() == s2.length()) { // On replace, move shorter pointer\n\t\t\t\t\tindex1++;\n\t\t\t\t}\n\t\t\t} else {\n\t\t\t\tindex1++; // If matching, move shorter pointer \n\t\t\t}\n\t\t\tindex2++; // Always move pointer for longer string \n\t\t}\n\t\treturn true;\n\t}\n\t\n\t\n\t\n\tpublic static void main(String[] args) {\n\t\tString a = \"palee\";\n\t\tString b = \"pale\";\n\t\tboolean isOneEdit1 = oneEditAway(a, b);\n\t\tSystem.out.println(a + \", \" + b + \": \" + isOneEdit1);\n\n\t\tString c = \"pale\";\n\t\tString d = \"pkle\";\n\t\tboolean isOneEdit2 = oneEditAway(c, d);\n\t\tSystem.out.println(c + \", \" + d + \": \" + isOneEdit2);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_05_One_Away/Tester.java",
"content": "package Q1_05_One_Away;\n\npublic class Tester {\n\t\n\tpublic static void test(String a, String b, boolean expected) {\n\t\tboolean resultA = QuestionA.oneEditAway(a, b);\n\t\tboolean resultB = QuestionB.oneEditAway(a, b);\t\t\n\t\t\n\t\tif (resultA == expected && resultB == expected) {\n\t\t\tSystem.out.println(a + \", \" + b + \": success\");\n\t\t} else {\n\t\t\tSystem.out.println(a + \", \" + b + \": error\");\n\t\t}\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString[][] tests = {{\"a\", \"b\", \"true\"}, \n\t\t\t\t{\"\", \"d\", \"true\"},\n\t\t\t\t{\"d\", \"de\", \"true\"},\n\t\t\t\t{\"pale\", \"pse\", \"false\"},\n\t\t\t\t{\"acdsfdsfadsf\", \"acdsgdsfadsf\", \"true\"},\n\t\t\t\t{\"acdsfdsfadsf\", \"acdsfdfadsf\", \"true\"},\n\t\t\t\t{\"acdsfdsfadsf\", \"acdsfdsfads\", \"true\"},\n\t\t\t\t{\"acdsfdsfadsf\", \"cdsfdsfadsf\", \"true\"},\n\t\t\t\t{\"adfdsfadsf\", \"acdfdsfdsf\", \"false\"},\n\t\t\t\t{\"adfdsfadsf\", \"bdfdsfadsg\", \"false\"},\n\t\t\t\t{\"adfdsfadsf\", \"affdsfads\", \"false\"},\n\t\t\t\t{\"pale\", \"pkle\", \"true\"},\n\t\t\t\t{\"pkle\", \"pable\", \"false\"}};\n\t\tfor (int i = 0; i < tests.length; i++) {\n\t\t\tString[] test = tests[i];\n\t\t\tString a = test[0];\n\t\t\tString b = test[1];\n\t\t\tboolean expected = test[2].equals(\"true\");\n\t\t\t\n\t\t\ttest(a, b, expected);\n\t\t\ttest(b, a, expected);\n\t\t}\n\t\t\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_06_String_Compression/QuestionA.java",
"content": "package Q1_06_String_Compression;\r\n\r\npublic class QuestionA {\t\r\n\tpublic static String compressBad(String str) {\r\n\t\tString compressedString = \"\";\r\n\t\tint countConsecutive = 0;\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tcountConsecutive++;\r\n\t\t\t\r\n\t\t\t/* If next character is different than current, append this char to result.*/\r\n\t\t\tif (i + 1 >= str.length() || str.charAt(i) != str.charAt(i + 1)) {\r\n\t\t\t\tcompressedString += \"\" + str.charAt(i) + countConsecutive;\r\n\t\t\t\tcountConsecutive = 0;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn compressedString.length() < str.length() ? compressedString : str;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = \"aa\";\r\n\t\tSystem.out.println(str);\r\n\t\tSystem.out.println(compressBad(str));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_06_String_Compression/QuestionB.java",
"content": "package Q1_06_String_Compression;\r\n\r\npublic class QuestionB {\t\r\n\tpublic static String compress(String str) {\r\n\t\tStringBuilder compressed = new StringBuilder();\r\n\t\tint countConsecutive = 0;\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tcountConsecutive++;\r\n\t\t\t\r\n\t\t\t/* If next character is different than current, append this char to result.*/\r\n\t\t\tif (i + 1 >= str.length() || str.charAt(i) != str.charAt(i + 1)) {\r\n\t\t\t\tcompressed.append(str.charAt(i));\r\n\t\t\t\tcompressed.append(countConsecutive);\r\n\t\t\t\tcountConsecutive = 0;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn compressed.length() < str.length() ? compressed.toString() : str;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = \"aa\";\r\n\t\tSystem.out.println(str);\r\n\t\tSystem.out.println(compress(str));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_06_String_Compression/QuestionC.java",
"content": "package Q1_06_String_Compression;\r\n\r\npublic class QuestionC {\t\r\n\tpublic static String compress(String str) {\r\n\t\tint finalLength = countCompression(str);\r\n\t\tif (finalLength >= str.length()) return str;\r\n\t\t\r\n\t\tStringBuffer compressed = new StringBuffer(finalLength); // initialize capacity\r\n\t\tint countConsecutive = 0;\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tcountConsecutive++;\r\n\t\t\t\r\n\t\t\t/* If next character is different than current, append this char to result.*/\r\n\t\t\tif (i + 1 >= str.length() || str.charAt(i) != str.charAt(i + 1)) {\r\n\t\t\t\tcompressed.append(str.charAt(i));\r\n\t\t\t\tcompressed.append(countConsecutive);\r\n\t\t\t\tcountConsecutive = 0;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn compressed.toString();\r\n\t}\r\n\t\r\n\tpublic static int countCompression(String str) {\r\n\t\tint compressedLength = 0;\r\n\t\tint countConsecutive = 0;\r\n\t\tfor (int i = 0; i < str.length(); i++) {\r\n\t\t\tcountConsecutive++;\r\n\t\t\t\r\n\t\t\t/* If next character is different than current, append this char to result.*/\r\n\t\t\tif (i + 1 >= str.length() || str.charAt(i) != str.charAt(i + 1)) {\r\n\t\t\t\tcompressedLength += 1 + String.valueOf(countConsecutive).length();\r\n\t\t\t\tcountConsecutive = 0;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn compressedLength;\r\n\t}\t\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = \"aa\";\r\n\t\tSystem.out.println(str);\r\n\t\tSystem.out.println(compress(str));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_06_String_Compression/Tester.java",
"content": "package Q1_06_String_Compression;\n\npublic class Tester {\n\n\tpublic static void main(String[] args) {\n\t\tString str = \"aaaaabbbbaaaabbddc\";\n\t\tSystem.out.println(str);\n\t\tSystem.out.println(QuestionA.compressBad(str));\n\t\tSystem.out.println(QuestionB.compress(str));\n\t\tSystem.out.println(QuestionC.compress(str));\n\t}\n\n}\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_07_Rotate_Matrix/Question.java",
"content": "package Q1_07_Rotate_Matrix;\r\n\r\nimport CtCILibrary.*;\r\n\r\npublic class Question {\r\n\r\n\tpublic static boolean rotate(int[][] matrix) {\r\n\t\tif (matrix.length == 0 || matrix.length != matrix[0].length) return false; // Not a square\r\n\t\tint n = matrix.length;\r\n\t\t\r\n\t\tfor (int layer = 0; layer < n / 2; layer++) {\r\n\t\t\tint first = layer;\r\n\t\t\tint last = n - 1 - layer;\r\n\t\t\tfor(int i = first; i < last; i++) {\r\n\t\t\t\tint offset = i - first;\r\n\t\t\t\tint top = matrix[first][i]; // save top\r\n\r\n\t\t\t\t// left -> top\r\n\t\t\t\tmatrix[first][i] = matrix[last-offset][first]; \t\t\t\r\n\r\n\t\t\t\t// bottom -> left\r\n\t\t\t\tmatrix[last-offset][first] = matrix[last][last - offset]; \r\n\r\n\t\t\t\t// right -> bottom\r\n\t\t\t\tmatrix[last][last - offset] = matrix[i][last]; \r\n\r\n\t\t\t\t// top -> right\r\n\t\t\t\tmatrix[i][last] = top; // right <- saved top\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[][] matrix = AssortedMethods.randomMatrix(3, 3, 0, 9);\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t\trotate(matrix);\r\n\t\tSystem.out.println();\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_08_Zero_Matrix/QuestionA.java",
"content": "package Q1_08_Zero_Matrix;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionA {\r\n\tpublic static void nullifyRow(int[][] matrix, int row) {\r\n\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\tmatrix[row][j] = 0;\r\n\t\t}\t\t\r\n\t}\r\n\r\n\tpublic static void nullifyColumn(int[][] matrix, int col) {\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tmatrix[i][col] = 0;\r\n\t\t}\t\t\r\n\t}\t\t\t\r\n\t\r\n\tpublic static void setZeros(int[][] matrix) {\r\n\t\tboolean[] row = new boolean[matrix.length];\t\r\n\t\tboolean[] column = new boolean[matrix[0].length];\r\n\r\n\t\t// Store the row and column index with value 0\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tfor (int j = 0; j < matrix[0].length;j++) {\r\n\t\t\t\tif (matrix[i][j] == 0) {\r\n\t\t\t\t\trow[i] = true; \r\n\t\t\t\t\tcolumn[j] = true;\r\n\t\t \t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\t// Nullify rows\r\n\t\tfor (int i = 0; i < row.length; i++) {\r\n\t\t\tif (row[i]) {\r\n\t\t\t\tnullifyRow(matrix, i);\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\t// Nullify columns\r\n\t\tfor (int j = 0; j < column.length; j++) {\r\n\t\t\tif (column[j]) {\r\n\t\t\t\tnullifyColumn(matrix, j);\r\n\t\t\t}\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tpublic static boolean matricesAreEqual(int[][] m1, int[][] m2) {\r\n\t\tif (m1.length != m2.length || m1[0].length != m2[0].length) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\t\r\n\t\tfor (int k = 0; k < m1.length; k++) {\r\n\t\t\tfor (int j = 0; j < m1[0].length; j++) {\r\n\t\t\t\tif (m1[k][j] != m2[k][j]) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\t\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static int[][] cloneMatrix(int[][] matrix) {\r\n\t\tint[][] c = new int[matrix.length][matrix[0].length];\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\t\tc[i][j] = matrix[i][j];\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn c;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint nrows = 10;\r\n\t\tint ncols = 15;\r\n\t\tint[][] matrix = AssortedMethods.randomMatrix(nrows, ncols, -10, 10);\t\t\r\n\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t\t\r\n\t\tsetZeros(matrix);\r\n\t\t\r\n\t\tSystem.out.println();\r\n\t\t\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_08_Zero_Matrix/QuestionB.java",
"content": "package Q1_08_Zero_Matrix;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionB {\r\n\tpublic static void nullifyRow(int[][] matrix, int row) {\r\n\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\tmatrix[row][j] = 0;\r\n\t\t}\t\t\r\n\t}\r\n\r\n\tpublic static void nullifyColumn(int[][] matrix, int col) {\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tmatrix[i][col] = 0;\r\n\t\t}\t\t\r\n\t}\t\t\r\n\t\r\n\tpublic static void setZeros(int[][] matrix) {\r\n\t\tboolean rowHasZero = false;\r\n\t\tboolean colHasZero = false;\t\t\r\n\t\t\r\n\t\t// Check if first row has a zero\r\n\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\tif (matrix[0][j] == 0) {\r\n\t\t\t\trowHasZero = true;\r\n\t\t\t\tbreak;\r\n\t\t\t}\r\n\t\t}\t\t\r\n\t\t\r\n\t\t// Check if first column has a zero\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tif (matrix[i][0] == 0) {\r\n\t\t\t\tcolHasZero = true;\r\n\t\t\t\tbreak;\r\n\t\t\t}\r\n\t\t}\t\t\r\n\t\t\r\n\t\t// Check for zeros in the rest of the array\r\n\t\tfor (int i = 1; i < matrix.length; i++) {\r\n\t\t\tfor (int j = 1; j < matrix[0].length;j++) {\r\n\t\t\t\tif (matrix[i][j] == 0) {\r\n\t\t\t\t\tmatrix[i][0] = 0;\r\n\t\t\t\t\tmatrix[0][j] = 0;\r\n\t\t \t\t}\r\n\t\t\t}\r\n\t\t}\t\t\r\n\t\t\r\n\t\t// Nullify rows based on values in first column\r\n\t\tfor (int i = 1; i < matrix.length; i++) {\r\n\t\t\tif (matrix[i][0] == 0) {\r\n\t\t\t\tnullifyRow(matrix, i);\r\n\t\t\t}\r\n\t\t}\t\t\r\n\t\t\r\n\t\t// Nullify columns based on values in first row\r\n\t\tfor (int j = 1; j < matrix[0].length; j++) {\r\n\t\t\tif (matrix[0][j] == 0) {\r\n\t\t\t\tnullifyColumn(matrix, j);\r\n\t\t\t}\r\n\t\t}\t\r\n\t\t\r\n\t\t// Nullify first row\r\n\t\tif (rowHasZero) {\r\n\t\t\tnullifyRow(matrix, 0);\r\n\t\t}\r\n\t\t\r\n\t\t// Nullify first column\r\n\t\tif (colHasZero) {\r\n\t\t\tnullifyColumn(matrix, 0);\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tpublic static boolean matricesAreEqual(int[][] m1, int[][] m2) {\r\n\t\tif (m1.length != m2.length || m1[0].length != m2[0].length) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\t\r\n\t\tfor (int k = 0; k < m1.length; k++) {\r\n\t\t\tfor (int j = 0; j < m1[0].length; j++) {\r\n\t\t\t\tif (m1[k][j] != m2[k][j]) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\t\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static int[][] cloneMatrix(int[][] matrix) {\r\n\t\tint[][] c = new int[matrix.length][matrix[0].length];\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\t\tc[i][j] = matrix[i][j];\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn c;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint nrows = 10;\r\n\t\tint ncols = 15;\r\n\t\tint[][] matrix = AssortedMethods.randomMatrix(nrows, ncols, -10, 10);\t\t\r\n\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t\t\r\n\t\tsetZeros(matrix);\r\n\t\t\r\n\t\tSystem.out.println();\r\n\t\t\r\n\t\tAssortedMethods.printMatrix(matrix);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_08_Zero_Matrix/Tester.java",
"content": "package Q1_08_Zero_Matrix;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Tester {\r\n\tpublic static boolean matricesAreEqual(int[][] m1, int[][] m2) {\r\n\t\tif (m1.length != m2.length || m1[0].length != m2[0].length) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\t\r\n\t\tfor (int k = 0; k < m1.length; k++) {\r\n\t\t\tfor (int j = 0; j < m1[0].length; j++) {\r\n\t\t\t\tif (m1[k][j] != m2[k][j]) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\t\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static int[][] cloneMatrix(int[][] matrix) {\r\n\t\tint[][] c = new int[matrix.length][matrix[0].length];\r\n\t\tfor (int i = 0; i < matrix.length; i++) {\r\n\t\t\tfor (int j = 0; j < matrix[0].length; j++) {\r\n\t\t\t\tc[i][j] = matrix[i][j];\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn c;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint nrows = 10;\r\n\t\tint ncols = 15;\r\n\t\tint[][] matrix1 = AssortedMethods.randomMatrix(nrows, ncols, -10, 10);\t\t\r\n\t\tint[][] matrix2 = cloneMatrix(matrix1);\r\n\r\n\t\tAssortedMethods.printMatrix(matrix1);\r\n\t\t\r\n\t\tQuestionA.setZeros(matrix1);\r\n\t\tQuestionB.setZeros(matrix2);\r\n\t\t\r\n\t\tSystem.out.println();\r\n\t\t\r\n\t\tAssortedMethods.printMatrix(matrix1);\r\n\t\tSystem.out.println();\r\n\t\tAssortedMethods.printMatrix(matrix2);\r\n\t\t\r\n\t\tif (matricesAreEqual(matrix1, matrix2)) {\r\n\t\t\tSystem.out.println(\"Equal\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"Not Equal\");\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 01. Arrays and Strings/Q1_09_String_Rotation/Question.java",
"content": "package Q1_09_String_Rotation;\r\n\r\npublic class Question {\r\n\tpublic static boolean isSubstring(String big, String small) {\r\n\t\tif (big.indexOf(small) >= 0) {\r\n\t\t\treturn true;\r\n\t\t} else {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static boolean isRotation(String s1, String s2) {\r\n\t int len = s1.length();\r\n\t /* check that s1 and s2 are equal length and not empty */\r\n\t if (len == s2.length() && len > 0) { \r\n\t \t/* concatenate s1 and s1 within new buffer */\r\n\t \tString s1s1 = s1 + s1;\r\n\t \treturn isSubstring(s1s1, s2);\r\n\t }\r\n\t return false;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString[][] pairs = {{\"apple\", \"pleap\"}, {\"waterbottle\", \"erbottlewat\"}, {\"camera\", \"macera\"}};\r\n\t\tfor (String[] pair : pairs) {\r\n\t\t\tString word1 = pair[0];\r\n\t\t\tString word2 = pair[1];\r\n\t\t\tboolean is_rotation = isRotation(word1, word2);\r\n\t\t\tSystem.out.println(word1 + \", \" + word2 + \": \" + is_rotation);\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_01_Remove_Dups/QuestionA.java",
"content": "package Q2_01_Remove_Dups;\r\n\r\nimport java.util.HashSet;\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionA {\r\n\tpublic static void deleteDups(LinkedListNode n) {\r\n\t\tHashSet set = new HashSet();\r\n\t\tLinkedListNode previous = null;\r\n\t\twhile (n != null) {\r\n\t\t\tif (set.contains(n.data)) {\r\n\t\t\t\tprevious.next = n.next;\r\n\t\t\t} else {\r\n\t\t\t\tset.add(n.data);\r\n\t\t\t\tprevious = n;\r\n\t\t\t}\r\n\t\t\tn = n.next;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\t\r\n\t\tLinkedListNode first = new LinkedListNode(0, null, null); //AssortedMethods.randomLinkedList(1000, 0, 2);\r\n\t\tLinkedListNode head = first;\r\n\t\tLinkedListNode second = first;\r\n\t\tfor (int i = 1; i < 8; i++) {\r\n\t\t\tsecond = new LinkedListNode(i % 2, null, null);\r\n\t\t\tfirst.setNext(second);\r\n\t\t\tsecond.setPrevious(first);\r\n\t\t\tfirst = second;\r\n\t\t}\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tdeleteDups(head);\r\n\t\tSystem.out.println(head.printForward());\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_01_Remove_Dups/QuestionB.java",
"content": "package Q2_01_Remove_Dups;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionB {\r\n\tpublic static void deleteDups(LinkedListNode head) {\r\n\t\tLinkedListNode current = head;\r\n\t\twhile (current != null) {\r\n\t\t\t/* Remove all future nodes that have the same value */\r\n\t\t\tLinkedListNode runner = current;\r\n\t\t\twhile (runner.next != null) { \r\n\t\t\t\tif (runner.next.data == current.data) {\r\n\t\t\t\t\trunner.next = runner.next.next;\r\n\t\t\t\t} else {\r\n\t\t\t\t\trunner = runner.next;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t\tcurrent = current.next;\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\t\r\n\t\tLinkedListNode first = new LinkedListNode(0, null, null); //AssortedMethods.randomLinkedList(1000, 0, 2);\r\n\t\tLinkedListNode head = first;\r\n\t\tLinkedListNode second = first;\r\n\t\tfor (int i = 1; i < 8; i++) {\r\n\t\t\tsecond = new LinkedListNode(i % 2, null, null);\r\n\t\t\tfirst.setNext(second);\r\n\t\t\tsecond.setPrevious(first);\r\n\t\t\tfirst = second;\r\n\t\t}\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tdeleteDups(head);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_01_Remove_Dups/QuestionC.java",
"content": "package Q2_01_Remove_Dups;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionC {\r\n\tpublic static void deleteDups(LinkedListNode head) {\r\n\t\tif (head == null) return;\r\n\t\tLinkedListNode previous = head;\r\n\t\tLinkedListNode current = previous.next;\r\n\t\twhile (current != null) {\r\n\t\t\t// Look backwards for dups, and remove any that you see.\r\n\t\t\tLinkedListNode runner = head;\r\n\t\t\twhile (runner != current) { \r\n\t\t\t\tif (runner.data == current.data) {\r\n\t\t\t\t\tLinkedListNode tmp = current.next;\r\n\t\t\t\t\tprevious.next = tmp;\r\n\t\t\t\t\tcurrent = tmp;\r\n\t\t\t\t\t/* We know we can't have more than one dup preceding\r\n\t\t\t\t\t * our element since it would have been removed \r\n\t\t\t\t\t * earlier. */\r\n\t\t\t\t break;\r\n\t\t\t\t}\r\n\t\t\t\trunner = runner.next;\r\n\t\t\t}\r\n\t\t\t\r\n\t\t\t/* If runner == current, then we didn't find any duplicate \r\n\t\t\t * elements in the previous for loop. We then need to \r\n\t\t\t * increment current. \r\n\t\t\t * If runner != current, then we must have hit the �break� \r\n\t\t\t * condition, in which case we found a dup and current has\r\n\t\t\t * already been incremented.*/\r\n\t\t\tif (runner == current) {\r\n\t\t\t\tprevious = current;\r\n\t\t current = current.next;\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\t\r\n\t\tLinkedListNode first = new LinkedListNode(0, null, null); //AssortedMethods.randomLinkedList(1000, 0, 2);\r\n\t\tLinkedListNode head = first;\r\n\t\tLinkedListNode second = first;\r\n\t\tfor (int i = 1; i < 8; i++) {\r\n\t\t\tsecond = new LinkedListNode(i % 2, null, null);\r\n\t\t\tfirst.setNext(second);\r\n\t\t\tsecond.setPrevious(first);\r\n\t\t\tfirst = second;\r\n\t\t}\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tdeleteDups(head);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_01_Remove_Dups/Tester.java",
"content": "package Q2_01_Remove_Dups;\n\nimport CtCILibrary.LinkedListNode;\n\npublic class Tester {\n\n\tpublic static void main(String[] args) {\n\t\tLinkedListNode first = new LinkedListNode(0, null, null); //AssortedMethods.randomLinkedList(1000, 0, 2);\n\t\tLinkedListNode head = first;\n\t\tLinkedListNode second = first;\n\t\tfor (int i = 1; i < 8; i++) {\n\t\t\tsecond = new LinkedListNode(i % 2, null, null);\n\t\t\tfirst.setNext(second);\n\t\t\tsecond.setPrevious(first);\n\t\t\tfirst = second;\n\t\t}\n\t\tSystem.out.println(head.printForward());\n\n\t\tLinkedListNode cloneA = head.clone();\n\t\tLinkedListNode cloneB = head.clone();\n\t\tLinkedListNode cloneC = head.clone();\n\t\tQuestionA.deleteDups(cloneA);\n\t\tQuestionA.deleteDups(cloneB);\n\t\tQuestionA.deleteDups(cloneC);\n\t\t\n\t\tSystem.out.println(cloneA.printForward());\n\t\tSystem.out.println(cloneB.printForward());\n\t\tSystem.out.println(cloneC.printForward());\n\t}\n\n}\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_02_Return_Kth_To_Last/QuestionA.java",
"content": "package Q2_02_Return_Kth_To_Last;\r\n\r\nimport CtCILibrary.*;\r\n\r\npublic class QuestionA {\r\n\r\n\tpublic static int printKthToLast(LinkedListNode head, int k) {\r\n\t\tif (head == null) {\r\n\t\t\treturn 0;\r\n\t\t}\r\n\t\tint index = printKthToLast(head.next, k) + 1;\r\n\t\tif (index == k) {\r\n\t\t\tSystem.out.println(k + \"th to last node is \" + head.data);\r\n\t\t}\r\n\t\treturn index;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {0, 1, 2, 3, 4, 5, 6};\r\n\t\tLinkedListNode head = AssortedMethods.createLinkedListFromArray(array);\r\n\t\tfor (int i = 0; i <= array.length + 1; i++) {\r\n\t\t\tprintKthToLast(head, i);\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_02_Return_Kth_To_Last/QuestionB.cpp",
"content": "#include \nusing namespace std;\n\nstruct node {\n\tnode * next;\n\tint data;\n};\n\nnode* nthToLast(node* head, int k, int& i) {\n\tif (head == NULL) {\n\t\treturn NULL;\n\t}\n\tnode * nd = nthToLast(head->next, k, i);\n\ti = i + 1;\n\tif (i == k) {\n\t\treturn head;\n\t}\n\treturn nd;\n}\n\nnode* nthToLast(node* head, int k) {\n\tint i = 0;\n\treturn nthToLast(head, k, i);\n}\n\nnode* createList(int count) {\n\tnode* head = new node();\n\thead->data = 0;\n\tnode* last = head;\n\tfor (int i = 1; i < count; i++) {\n\t\tnode* n = new node();\n\t\tn->data = i;\n\t\tlast->next = n;\n\t\tlast = n;\n\t}\n\treturn head;\n}\n\nvoid printList(node* head) {\n\twhile (head != NULL) {\n\t\tprintf(\"%d\", head->data);\n\t\thead = head->next;\n\t}\n}\n\nint main() {\n\tint count = 5;\n\tnode* head = createList(count);\n\tprintList(head);\n\tprintf(\"\\n\");\n\tfor (int k = 0; k <= count; k++) {\n\t\tnode* n = nthToLast(head, k);\n\t\tif (n != NULL) {\n\t\t\tint data = n->data;\n\t\t\tprintf(\"%d: \", k);\n\t\t\tprintf(\"%d\", n->data);\n\t\t\tprintf(\"\\n\");\n\t\t}\n\t}\n\treturn 0;\n}"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_02_Return_Kth_To_Last/QuestionC.java",
"content": "package Q2_02_Return_Kth_To_Last;\r\n\r\nimport CtCILibrary.*;\r\n\r\npublic class QuestionC {\r\n\tpublic static class Index {\r\n\t\tpublic int value = 0;\r\n\t}\t\r\n\t\r\n\tpublic static LinkedListNode kthToLast(LinkedListNode head, int k) {\r\n\t\tIndex idx = new Index();\r\n\t\treturn kthToLast(head, k, idx);\r\n\t}\r\n\t\r\n\tpublic static LinkedListNode kthToLast(LinkedListNode head, int k, Index idx) {\r\n\t\tif (head == null) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\tLinkedListNode node = kthToLast(head.next, k, idx);\r\n\t\tidx.value = idx.value + 1;\r\n\t\tif (idx.value == k) {\r\n\t\t\treturn head;\r\n\t\t} \r\n\t\treturn node;\r\n\t}\t\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {0, 1, 2, 3, 4, 5, 6};\r\n\t\tLinkedListNode head = AssortedMethods.createLinkedListFromArray(array);\r\n\t\tfor (int i = 0; i <= array.length + 1; i++) {\r\n\t\t\tLinkedListNode node = kthToLast(head, i);\r\n\t\t\tString nodeValue = node == null ? \"null\" : \"\" + node.data;\r\n\t\t\tSystem.out.println(i + \": \" + nodeValue);\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_02_Return_Kth_To_Last/QuestionD.java",
"content": "package Q2_02_Return_Kth_To_Last;\r\n\r\nimport CtCILibrary.*;\r\n\r\npublic class QuestionD {\r\n\t\r\n\tpublic static LinkedListNode nthToLast(LinkedListNode head, int k) {\r\n\t\tLinkedListNode p1 = head;\r\n\t\tLinkedListNode p2 = head;\r\n\t\t\r\n\t\t/* Move p1 k nodes into the list.*/\r\n\t\tfor (int i = 0; i < k; i++) {\r\n\t\t\tif (p1 == null) return null; // Out of bounds\r\n\t\t\tp1 = p1.next;\r\n\t\t}\r\n\t\t\r\n\t\t/* Move them at the same pace. When p1 hits the end, \r\n\t\t * p2 will be at the right element. */\r\n\t\twhile (p1 != null) {\r\n\t\t\tp1 = p1.next;\r\n\t\t\tp2 = p2.next;\r\n\t \t}\r\n\t \treturn p2;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {0, 1, 2, 3};\r\n\t\tLinkedListNode head = AssortedMethods.createLinkedListFromArray(array);\r\n\t\tfor (int i = 0; i <= array.length + 1; i++) {\r\n\t\t\tLinkedListNode node = nthToLast(head, i);\r\n\t\t\tString nodeValue = node == null ? \"null\" : \"\" + node.data;\r\n\t\t\tSystem.out.println(i + \": \" + nodeValue);\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_02_Return_Kth_To_Last/Tester.java",
"content": "package Q2_02_Return_Kth_To_Last;\n\nimport CtCILibrary.AssortedMethods;\n\npublic class Tester {\n\n\t\n\tpublic static void main(String[] args) {\n\n\t}\n\n}\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_03_Delete_Middle_Node/Question.java",
"content": "package Q2_03_Delete_Middle_Node;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class Question {\r\n\r\n\tpublic static boolean deleteNode(LinkedListNode n) {\r\n\t\tif (n == null || n.next == null) {\r\n\t\t\treturn false; // Failure\r\n\t\t} \r\n\t\tLinkedListNode next = n.next; \r\n\t\tn.data = next.data; \r\n\t\tn.next = next.next; \r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tLinkedListNode head = AssortedMethods.randomLinkedList(10, 0, 10);\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tdeleteNode(head.next.next.next.next); // delete node 4\r\n\t\tSystem.out.println(head.printForward());\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_04_Partition/Question.java",
"content": "package Q2_04_Partition;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class Question {\r\n\r\n\tpublic static LinkedListNode partition(LinkedListNode node, int x) {\r\n\t\tLinkedListNode beforeStart = null;\r\n\t\tLinkedListNode beforeEnd = null;\r\n\t\tLinkedListNode afterStart = null;\r\n\t\tLinkedListNode afterEnd = null;\r\n\t\t\r\n\t\t/* Partition list */\r\n\t\twhile (node != null) {\r\n\t\t\tLinkedListNode next = node.next;\r\n\t\t\tnode.next = null;\r\n\t\t\tif (node.data < x) {\r\n\t\t\t\tif (beforeStart == null) {\r\n\t\t\t\t\tbeforeStart = node;\r\n\t\t\t\t\tbeforeEnd = beforeStart;\r\n\t\t\t\t} else {\r\n\t\t\t\t\tbeforeEnd.next = node;\r\n\t\t\t\t\tbeforeEnd = node;\r\n\t\t\t\t}\r\n\t\t\t} else {\r\n\t\t\t\tif (afterStart == null) {\r\n\t\t\t\t\tafterStart = node;\r\n\t\t\t\t\tafterEnd = afterStart;\r\n\t\t\t\t} else {\r\n\t\t\t\t\tafterEnd.next = node;\r\n\t\t\t\t\tafterEnd = node;\r\n\t\t\t\t}\r\n\t\t\t}\t\r\n\t\t\tnode = next;\r\n\t\t}\r\n\t\t\r\n\t\t/* Merge before list and after list */\r\n\t\tif (beforeStart == null) {\r\n\t\t\treturn afterStart;\r\n\t\t}\r\n\t\t\r\n\t\tbeforeEnd.next = afterStart;\r\n\t\treturn beforeStart;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\t/* Create linked list */\r\n\t\tint[] vals = {33,9,2,3,10,10389,838,874578,5};\r\n\t\tLinkedListNode head = new LinkedListNode(vals[0], null, null);\r\n\t\tLinkedListNode current = head;\r\n\t\tfor (int i = 1; i < vals.length; i++) {\r\n\t\t\tcurrent = new LinkedListNode(vals[i], null, current);\r\n\t\t}\r\n\t\tSystem.out.println(head.printForward());\r\n\t\t\r\n\t\t/* Partition */\r\n\t\tLinkedListNode h = partition(head, 3);\r\n\t\t\r\n\t\t/* Print Result */\r\n\t\tSystem.out.println(h.printForward());\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_04_Partition/QuestionB.java",
"content": "package Q2_04_Partition;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionB {\r\n\r\n\tpublic static LinkedListNode partition(LinkedListNode node, int x) {\r\n\t\tLinkedListNode beforeStart = null;\r\n\t\tLinkedListNode afterStart = null;\r\n\t\t\r\n\t\t/* Partition list */\r\n\t\twhile (node != null) {\r\n\t\t\tLinkedListNode next = node.next;\r\n\t\t\tif (node.data < x) {\r\n\t\t\t\t/* Insert node into start of before list */\r\n\t\t\t\tnode.next = beforeStart;\r\n\t\t\t\tbeforeStart = node;\t\r\n\t\t\t} else {\r\n\t\t\t\t/* Insert node into front of after list */\r\n\t\t\t\tnode.next = afterStart;\r\n\t\t\t\tafterStart = node;\r\n\t\t\t}\t\r\n\t\t\tnode = next;\r\n\t\t}\r\n\t\t\r\n\t\t/* Merge before list and after list */\r\n\t\tif (beforeStart == null) {\r\n\t\t\treturn afterStart;\r\n\t\t}\r\n\t\t\r\n\t\tLinkedListNode head = beforeStart;\r\n\t\twhile (beforeStart.next != null) {\r\n\t\t\tbeforeStart = beforeStart.next;\r\n\t\t}\r\n\t\tbeforeStart.next = afterStart;\r\n\t\treturn head;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint length = 20;\r\n\t\tLinkedListNode[] nodes = new LinkedListNode[length];\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\r\n\t\t}\r\n\t\t\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tif (i < length - 1) {\r\n\t\t\t\tnodes[i].setNext(nodes[i + 1]);\r\n\t\t\t}\r\n\t\t\tif (i > 0) {\r\n\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\tLinkedListNode head = nodes[0];\r\n\t\tSystem.out.println(head.printForward());\r\n\t\t\r\n\t\tLinkedListNode h = partition(head, 7);\r\n\t\tSystem.out.println(h.printForward());\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_04_Partition/QuestionC.java",
"content": "package Q2_04_Partition;\n\nimport CtCILibrary.LinkedListNode;\n\npublic class QuestionC {\n\n\tpublic static LinkedListNode partition(LinkedListNode node, int x) {\n\t\tLinkedListNode head = node;\n\t\tLinkedListNode tail = node;\n\t\t\n\t\t/* Partition list */\n\t\twhile (node != null) {\n\t\t\tLinkedListNode next = node.next;\n\t\t\tif (node.data < x) {\n\t\t\t\t/* Insert node at head. */\n\t\t\t\tnode.next = head;\n\t\t\t\thead = node;\n\t\t\t} else {\n\t\t\t\t/* Insert node at tail. */\n\t\t\t\ttail.next = node;\n\t\t\t\ttail = node;\n\t\t\t}\t\n\t\t\tnode = next;\n\t\t}\n\t\ttail.next = null;\n\t\t\n\t\treturn head;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint length = 20;\n\t\tLinkedListNode[] nodes = new LinkedListNode[length];\n\t\tfor (int i = 0; i < length; i++) {\n\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\n\t\t}\n\t\t\n\t\tfor (int i = 0; i < length; i++) {\n\t\t\tif (i < length - 1) {\n\t\t\t\tnodes[i].setNext(nodes[i + 1]);\n\t\t\t}\n\t\t\tif (i > 0) {\n\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\n\t\t\t}\n\t\t}\n\t\t\n\t\tLinkedListNode head = nodes[0];\n\t\tSystem.out.println(head.printForward());\n\t\t\n\t\tLinkedListNode h = partition(head, 8);\n\t\tSystem.out.println(h.printForward());\n\t}\n\n}\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_04_Partition/Tester.java",
"content": "package Q2_04_Partition;\n\nimport CtCILibrary.LinkedListNode;\n\npublic class Tester {\n\t\n\tpublic static LinkedListNode createLinkedList() {\n\t\t/* Create linked list */\n\t\tint[] vals = {3, 5, 8, 5, 10, 2, 1};\n\t\tLinkedListNode head = new LinkedListNode(vals[0], null, null);\n\t\tLinkedListNode current = head;\n\t\tfor (int i = 1; i < vals.length; i++) {\n\t\t\tcurrent = new LinkedListNode(vals[i], null, current);\n\t\t}\n\t\treturn head;\n\t}\n\n\tpublic static void main(String[] args) {\n\t\tSystem.out.println(createLinkedList().printForward());\n\t\t\n\t\t/* Partition */\n\t\tLinkedListNode hA = Question.partition(createLinkedList(), 5);\n\t\tLinkedListNode hB = QuestionB.partition(createLinkedList(), 5);\n\t\tLinkedListNode hC = QuestionC.partition(createLinkedList(), 5);\n\t\t\n\t\t/* Print Result */\n\t\tSystem.out.println(hA.printForward());\n\t\tSystem.out.println(hB.printForward());\n\t\tSystem.out.println(hC.printForward());\n\t}\n\n}\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_05_Sum_Lists/PartialSum.java",
"content": "package Q2_05_Sum_Lists;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class PartialSum {\r\n\tpublic LinkedListNode sum = null;\r\n\tpublic int carry = 0;\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_05_Sum_Lists/QuestionA.java",
"content": "package Q2_05_Sum_Lists;\r\n\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionA {\r\n\tprivate static LinkedListNode addLists(LinkedListNode l1, LinkedListNode l2) {\r\n\t\treturn addLists(l1, l2, 0);\r\n\t}\r\n\t\r\n\tprivate static LinkedListNode addLists(LinkedListNode l1, LinkedListNode l2, int carry) {\r\n\t\tif (l1 == null && l2 == null && carry == 0) {\r\n return null;\r\n\t\t}\r\n\t\t\r\n\t\tLinkedListNode result = new LinkedListNode();\r\n\t\tint value = carry;\r\n\t\tif (l1 != null) {\r\n\t\t\tvalue += l1.data;\r\n\t\t}\r\n\t\tif (l2 != null) {\r\n\t\t\tvalue += l2.data;\r\n\t\t}\r\n\t\tresult.data = value % 10;\r\n\t\tif (l1 != null || l2 != null) {\r\n\t\t\tLinkedListNode more = addLists(l1 == null ? null : l1.next, \r\n\t\t\t\t\t\t\t\t\t\t l2 == null ? null : l2.next, \r\n\t\t\t\t\t\t\t\t\t\t value >= 10 ? 1 : 0);\r\n\t\t\tresult.setNext(more);\r\n\t\t}\r\n\t\treturn result;\r\n\t}\r\n\t\r\n\tpublic static int linkedListToInt(LinkedListNode node) {\r\n\t\tint value = 0;\r\n\t\tif (node.next != null) {\r\n\t\t\tvalue = 10 * linkedListToInt(node.next);\r\n\t\t}\r\n\t\treturn value + node.data;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tLinkedListNode lA1 = new LinkedListNode(9, null, null);\r\n\t\tLinkedListNode lA2 = new LinkedListNode(9, null, lA1);\r\n\t\tLinkedListNode lA3 = new LinkedListNode(9, null, lA2);\r\n\t\t\r\n\t\tLinkedListNode lB1 = new LinkedListNode(1, null, null);\r\n\t\tLinkedListNode lB2 = new LinkedListNode(0, null, lB1);\r\n\t\tLinkedListNode lB3 = new LinkedListNode(0, null, lB2);\t\r\n\t\t\r\n\t\tLinkedListNode list3 = addLists(lA1, lB1);\r\n\t\t\r\n\t\tSystem.out.println(\" \" + lA1.printForward());\t\t\r\n\t\tSystem.out.println(\"+ \" + lB1.printForward());\t\t\t\r\n\t\tSystem.out.println(\"= \" + list3.printForward());\t\r\n\t\t\r\n\t\tint l1 = linkedListToInt(lA1);\r\n\t\tint l2 = linkedListToInt(lB1);\r\n\t\tint l3 = linkedListToInt(list3);\r\n\t\t\r\n\t\tSystem.out.print(l1 + \" + \" + l2 + \" = \" + l3 + \"\\n\");\r\n\t\tSystem.out.print(l1 + \" + \" + l2 + \" = \" + (l1 + l2));\t\t\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_05_Sum_Lists/QuestionB.java",
"content": "package Q2_05_Sum_Lists;\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionB {\r\n\tprivate static int length(LinkedListNode l) {\r\n\t\tif (l == null) {\r\n\t\t\treturn 0;\r\n\t\t} else {\r\n\t\t\treturn 1 + length(l.next);\r\n\t\t}\r\n\t}\r\n\t\r\n\tprivate static PartialSum addListsHelper(LinkedListNode l1, LinkedListNode l2) {\r\n\t\tif (l1 == null && l2 == null) {\r\n\t\t\tPartialSum sum = new PartialSum();\r\n\t\t\treturn sum;\r\n\t\t}\r\n\t\tPartialSum sum = addListsHelper(l1.next, l2.next);\r\n\t\tint val = sum.carry + l1.data + l2.data;\r\n\t\tLinkedListNode full_result = insertBefore(sum.sum, val % 10);\r\n\t\tsum.sum = full_result;\r\n\t\tsum.carry = val / 10;\r\n\t\treturn sum;\r\n\t}\r\n\t\r\n\tprivate static LinkedListNode addLists(LinkedListNode l1, LinkedListNode l2) {\r\n\t\tint len1 = length(l1);\r\n\t\tint len2 = length(l2);\r\n\t\tif (len1 < len2) {\r\n\t\t\tl1 = padList(l1, len2 - len1);\r\n\t\t} else {\r\n\t\t\tl2 = padList(l2, len1 - len2);\r\n\t\t}\r\n\t\tPartialSum sum = addListsHelper(l1, l2);\r\n\t\tif (sum.carry == 0) {\r\n\t\t\treturn sum.sum;\r\n\t\t} else {\r\n\t\t\tLinkedListNode result = insertBefore(sum.sum, sum.carry);\r\n\t\t\treturn result;\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tprivate static LinkedListNode padList(LinkedListNode l, int padding) {\r\n\t\tLinkedListNode head = l;\r\n\t\tfor (int i = 0; i < padding; i++) {\r\n\t\t\thead = insertBefore(head, 0);\r\n\t\t}\r\n\t\treturn head;\r\n\t}\r\n\t\r\n\tprivate static LinkedListNode insertBefore(LinkedListNode list, int data) {\r\n\t\tLinkedListNode node = new LinkedListNode(data);\r\n\t\tif (list != null) {\r\n\t\t\tnode.next = list;\r\n\t\t}\r\n\t\treturn node;\r\n\t}\r\n\t\r\n\tpublic static int linkedListToInt(LinkedListNode node) {\r\n\t\tint value = 0;\r\n\t\twhile (node != null) {\r\n\t\t\tvalue = value * 10 + node.data;\r\n\t\t\tnode = node.next;\r\n\t\t}\r\n\t\treturn value;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tLinkedListNode lA1 = new LinkedListNode(3, null, null);\r\n\t\tLinkedListNode lA2 = new LinkedListNode(1, null, lA1);\r\n\t\t\r\n\t\tLinkedListNode lB1 = new LinkedListNode(5, null, null);\r\n\t\tLinkedListNode lB2 = new LinkedListNode(9, null, lB1);\r\n\t\tLinkedListNode lB3 = new LinkedListNode(1, null, lB2);\t\r\n\t\t\r\n\t\tLinkedListNode list3 = addLists(lA1, lB1);\r\n\t\t\r\n\t\tSystem.out.println(\" \" + lA1.printForward());\t\t\r\n\t\tSystem.out.println(\"+ \" + lB1.printForward());\t\t\t\r\n\t\tSystem.out.println(\"= \" + list3.printForward());\t\r\n\t\t\r\n\t\tint l1 = linkedListToInt(lA1);\r\n\t\tint l2 = linkedListToInt(lB1);\r\n\t\tint l3 = linkedListToInt(list3);\r\n\t\t\r\n\t\tSystem.out.print(l1 + \" + \" + l2 + \" = \" + l3 + \"\\n\");\r\n\t\tSystem.out.print(l1 + \" + \" + l2 + \" = \" + (l1 + l2));\t\t\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_06_Palindrome/QuestionA.java",
"content": "package Q2_06_Palindrome;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionA {\r\n\tpublic static boolean isPalindrome(LinkedListNode head) {\r\n\t\tLinkedListNode reversed = reverseAndClone(head);\r\n\t\treturn isEqual(head, reversed);\r\n\t}\r\n\t\t\r\n\tpublic static LinkedListNode reverseAndClone(LinkedListNode node) {\r\n\t\tLinkedListNode head = null;\r\n\t\twhile (node != null) {\r\n\t\t\tLinkedListNode n = new LinkedListNode(node.data); // Clone\r\n\t\t\tn.next = head;\r\n\t\t\thead = n;\r\n\t\t\tnode = node.next;\r\n\t\t}\r\n\t\treturn head;\r\n\t}\t\r\n\t\t\r\n\tpublic static boolean isEqual(LinkedListNode one, LinkedListNode two) {\r\n\t\twhile (one != null && two != null) {\r\n\t\t\tif (one.data != two.data) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tone = one.next;\r\n\t\t\ttwo = two.next;\r\n\t\t}\r\n\t\treturn one == null && two == null;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint length = 9;\r\n\t\tLinkedListNode[] nodes = new LinkedListNode[length];\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\r\n\t\t}\r\n\t\t\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tif (i < length - 1) {\r\n\t\t\t\tnodes[i].setNext(nodes[i + 1]);\r\n\t\t\t}\r\n\t\t\tif (i > 0) {\r\n\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\r\n\t\t\t}\r\n\t\t}\r\n\t\t// nodes[length - 2].data = 9; // Uncomment to ruin palindrome\r\n\t\t\r\n\t\tLinkedListNode head = nodes[0];\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tSystem.out.println(isPalindrome(head));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_06_Palindrome/QuestionB.java",
"content": "package Q2_06_Palindrome;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\nimport java.util.Stack;\r\n\r\npublic class QuestionB {\r\n\tpublic static boolean isPalindrome(LinkedListNode head) {\r\n\t\tLinkedListNode fast = head;\r\n\t\tLinkedListNode slow = head;\r\n\t\t\r\n\t\tStack stack = new Stack();\r\n\t\t\r\n\t\twhile (fast != null && fast.next != null) {\r\n\t\t\tstack.push(slow.data);\r\n\t\t\tslow = slow.next;\r\n\t\t\tfast = fast.next.next;\t\t\t\r\n\t\t}\r\n\t\t\r\n\t\t/* Has odd number of elements, so skip the middle */\r\n\t\tif (fast != null) { \r\n\t\t\tslow = slow.next;\r\n\t\t}\r\n\t\t\r\n\t\twhile (slow != null) {\r\n\t\t\tint top = stack.pop().intValue();\r\n\t\t\tif (top != slow.data) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tslow = slow.next;\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint length = 9;\r\n\t\tLinkedListNode[] nodes = new LinkedListNode[length];\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\r\n\t\t}\r\n\t\t\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tif (i < length - 1) {\r\n\t\t\t\tnodes[i].setNext(nodes[i + 1]);\r\n\t\t\t}\r\n\t\t\tif (i > 0) {\r\n\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\r\n\t\t\t}\r\n\t\t}\r\n\t\t//nodes[length - 2].data = 9; // Uncomment to ruin palindrome\r\n\t\t\r\n\t\tLinkedListNode head = nodes[0];\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tSystem.out.println(isPalindrome(head));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_06_Palindrome/QuestionC.java",
"content": "package Q2_06_Palindrome;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class QuestionC {\r\n\tpublic static class Result {\r\n\t\tpublic LinkedListNode node;\r\n\t\tpublic boolean result;\r\n\t\tpublic Result(LinkedListNode n, boolean res) {\r\n\t\t\tnode = n;\r\n\t\t\tresult = res;\r\n\t\t}\r\n\t}\r\n\r\n\tpublic static Result isPalindromeRecurse(LinkedListNode head, int length) {\r\n\t\tif (head == null || length <= 0) { // Even number of nodes\r\n\t\t\treturn new Result(head, true);\r\n\t\t} else if (length == 1) { // Odd number of nodes\r\n\t\t\treturn new Result(head.next, true);\r\n\t\t} \r\n\t\t\r\n\t\t/* Recurse on sublist. */\r\n\t\tResult res = isPalindromeRecurse(head.next, length - 2);\r\n\t\t\r\n\t\t/* If child calls are not a palindrome, pass back up \r\n\t\t * a failure. */\r\n\t\tif (!res.result || res.node == null) {\r\n\t\t\treturn res;\r\n\t\t} \r\n\t\t\r\n\t\t/* Check if matches corresponding node on other side. */\r\n\t\tres.result = (head.data == res.node.data); \r\n\t\t\r\n\t\t/* Return corresponding node. */\r\n\t\tres.node = res.node.next;\r\n\t\t\r\n\t\treturn res;\r\n\t}\r\n\t\r\n\tpublic static int lengthOfList(LinkedListNode n) {\r\n\t\tint size = 0;\r\n\t\twhile (n != null) {\r\n\t\t\tsize++;\r\n\t\t\tn = n.next;\r\n\t\t}\r\n\t\treturn size;\r\n\t}\r\n\t\r\n\tpublic static boolean isPalindrome(LinkedListNode head) {\r\n\t\tint length = lengthOfList(head);\r\n\t\tResult p = isPalindromeRecurse(head, length);\r\n\t\treturn p.result;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint length = 9;\r\n\t\tLinkedListNode[] nodes = new LinkedListNode[length];\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\r\n\t\t}\r\n\t\t\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tif (i < length - 1) {\r\n\t\t\t\tnodes[i].setNext(nodes[i + 1]);\r\n\t\t\t}\r\n\t\t\tif (i > 0) {\r\n\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\r\n\t\t\t}\r\n\t\t}\r\n\t\t//nodes[length - 2].data = 9; // Uncomment to ruin palindrome\r\n\t\t\r\n\t\tLinkedListNode head = nodes[0];\r\n\t\tSystem.out.println(head.printForward());\r\n\t\tSystem.out.println(isPalindrome(head));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_06_Palindrome/Tester.java",
"content": "package Q2_06_Palindrome;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class Tester {\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint max = 11;\r\n\t\tfor (int length = 1; length < max; length++) {\r\n\t\t\tLinkedListNode[] nodes = new LinkedListNode[length];\r\n\t\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\t\tnodes[i] = new LinkedListNode(i >= length / 2 ? length - i - 1 : i, null, null);\r\n\t\t\t}\r\n\t\t\t\r\n\t\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\t\tif (i < length - 1) {\r\n\t\t\t\t\tnodes[i].setNext(nodes[i + 1]);\r\n\t\t\t\t}\r\n\t\t\t\tif (i > 0) {\r\n\t\t\t\t\tnodes[i].setPrevious(nodes[i - 1]);\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t\tfor (int i = -1; i < length; i++) {\r\n\t\t\t\tif (i >= 0) {\r\n\t\t\t\t\tnodes[i].data++; // Ruin palindrome\r\n\t\t\t\t}\r\n\t\t\t\t\r\n\t\t\t\tLinkedListNode head = nodes[0];\r\n\t\t\t\tSystem.out.println(head.printForward());\r\n\t\t\t\tboolean resultA = QuestionA.isPalindrome(head);\r\n\t\t\t\tboolean resultB = QuestionB.isPalindrome(head);\r\n\t\t\t\tboolean resultC = QuestionC.isPalindrome(head);\r\n\t\t\t\tSystem.out.println(\"A: \" + resultA);\r\n\t\t\t\tSystem.out.println(\"B: \" + resultB);\r\n\t\t\t\tSystem.out.println(\"C: \" + resultC);\r\n\t\t\t\tif (resultA != resultB || resultB != resultC) {\r\n\t\t\t\t\tSystem.out.println(\"ERROR\");\r\n\t\t\t\t\tlength = max;\r\n\t\t\t\t\tbreak;\r\n\t\t\t\t}\r\n\t\t\t\tif (i >= 0) {\r\n\t\t\t\t\tnodes[i].data--;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_07_Intersection/Question.java",
"content": "package Q2_07_Intersection;\n\nimport CtCILibrary.AssortedMethods;\nimport CtCILibrary.LinkedListNode;\n\npublic class Question {\n\n\tpublic static class Result {\n\t\tpublic LinkedListNode tail;\n\t\tpublic int size;\n\t\tpublic Result(LinkedListNode tail, int size) {\n\t\t\tthis.tail = tail;\n\t\t\tthis.size = size;\n\t\t}\n\t}\n\t\n\tpublic static Result getTailAndSize(LinkedListNode list) {\n\t\tif (list == null) return null;\n\t\t\n\t\tint size = 1;\n\t\tLinkedListNode current = list;\n\t\twhile (current.next != null) {\n\t\t\tsize++;\n\t\t\tcurrent = current.next;\n\t\t}\n\t\treturn new Result(current, size);\n\t}\n\t\n\tpublic static LinkedListNode getKthNode(LinkedListNode head, int k) {\n\t\tLinkedListNode current = head;\n\t\twhile (k > 0 && current != null) {\n\t\t\tcurrent = current.next;\n\t\t\tk--;\n\t\t}\n\t\treturn current;\n\t}\n\t\n\tpublic static LinkedListNode findIntersection(LinkedListNode list1, LinkedListNode list2) {\n\t\tif (list1 == null || list2 == null) return null;\n\t\t\n\t\t/* Get tail and sizes. */\n\t\tResult result1 = getTailAndSize(list1);\n\t\tResult result2 = getTailAndSize(list2);\n\t\t\n\t\t/* If different tail nodes, then there's no intersection. */\n\t\tif (result1.tail != result2.tail) {\n\t\t\treturn null;\n\t\t}\n\t\t\n\t\t/* Set pointers to the start of each linked list. */\n\t\tLinkedListNode shorter = result1.size < result2.size ? list1 : list2;\n\t\tLinkedListNode longer = result1.size < result2.size ? list2 : list1;\n\t\t\n\t\t/* Advance the pointer for the longer linked list by the difference in lengths. */\n\t\tlonger = getKthNode(longer, Math.abs(result1.size - result2.size));\n\t\t\n\t\t/* Move both pointers until you have a collision. */\n\t\twhile (shorter != longer) {\n\t\t\tshorter = shorter.next;\n\t\t\tlonger = longer.next;\n\t\t}\n\t\t\n\t\t/* Return either one. */\n\t\treturn longer; \n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\t/* Create linked list */\n\t\tint[] vals = {-1, -2, 0, 1, 2, 3, 4, 5, 6, 7, 8};\n\t\tLinkedListNode list1 = AssortedMethods.createLinkedListFromArray(vals);\n\t\t\n\t\tint[] vals2 = {12, 14, 15};\n\t\tLinkedListNode list2 = AssortedMethods.createLinkedListFromArray(vals2);\n\t\t\n\t\tlist2.next.next = list1.next.next.next.next;\n\t\t\n\t\tSystem.out.println(list1.printForward());\n\t\tSystem.out.println(list2.printForward());\n\t\t\n\t\t\n\t\tLinkedListNode intersection = findIntersection(list1, list2);\n\t\t\n\t\tSystem.out.println(intersection.printForward());\n\t}\n\n}\n"
},
{
"path": "Java/Ch 02. Linked Lists/Q2_08_Loop_Detection/Question.java",
"content": "package Q2_08_Loop_Detection;\r\n\r\nimport CtCILibrary.LinkedListNode;\r\n\r\npublic class Question {\r\n\r\n\tpublic static LinkedListNode FindBeginning(LinkedListNode head) {\r\n\t\tLinkedListNode slow = head;\r\n\t\tLinkedListNode fast = head; \r\n\t\t\r\n\t\t// Find meeting point\r\n\t\twhile (fast != null && fast.next != null) { \r\n\t\t\tslow = slow.next; \r\n\t\t\tfast = fast.next.next;\r\n\t\t\tif (slow == fast) {\r\n\t\t\t\tbreak;\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\t// Error check - there is no meeting point, and therefore no loop\r\n\t\tif (fast == null || fast.next == null) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\r\n\t\t/* Move slow to Head. Keep fast at Meeting Point. Each are k steps\r\n\t\t/* from the Loop Start. If they move at the same pace, they must\r\n\t\t * meet at Loop Start. */\r\n\t\tslow = head; \r\n\t\twhile (slow != fast) { \r\n\t\t\tslow = slow.next; \r\n\t\t\tfast = fast.next; \r\n\t\t}\r\n\t\t\r\n\t\t// Both now point to the start of the loop.\r\n\t\treturn fast;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint list_length = 100;\r\n\t\tint k = 10;\r\n\t\t\r\n\t\t// Create linked list\r\n\t\tLinkedListNode[] nodes = new LinkedListNode[list_length];\r\n\t\tfor (int i = 0; i < list_length; i++) {\r\n\t\t\tnodes[i] = new LinkedListNode(i, null, i > 0 ? nodes[i - 1] : null);\r\n\t\t}\r\n\t\t\r\n\t\t// Create loop;\r\n\t\tnodes[list_length - 1].next = nodes[list_length - k];\r\n\t\t\r\n\t\tLinkedListNode loop = FindBeginning(nodes[0]);\r\n\t\tif (loop == null) {\r\n\t\t\tSystem.out.println(\"No Cycle.\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(loop.data);\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Introduction/MyQueue.java",
"content": "package Introduction;\n\nimport java.util.NoSuchElementException;\n\npublic class MyQueue {\n\tprivate static class QueueNode {\n\t\tprivate T data;\n\t\tprivate QueueNode next;\n\t\t\n\t\tpublic QueueNode(T data) {\n\t\t\tthis.data = data;\n\t\t}\n\t}\n\t\n\tprivate QueueNode first;\n\tprivate QueueNode last;\n\n\tpublic void add(T item) { \n\t\tQueueNode t = new QueueNode(item);\n\t\tif (last != null) {\n\t\t\tlast.next = t;\n\t\t}\n\t\tlast = t;\n\t\tif (first == null) {\n\t\t\tfirst = last;\n\t\t}\n\t} \n\n\tpublic T remove() {\n\t\tif (first == null) throw new NoSuchElementException();\n\t\tT data = first.data;\n\t\tfirst = first.next;\n\t\tif (first == null) {\n\t\t\tlast = null;\n\t\t}\n\t\treturn data;\n\t}\n\t\n\tpublic T peek() {\n\t\tif (first == null) throw new NoSuchElementException();\n\t\treturn first.data;\n\t}\n\t\n\tpublic boolean isEmpty() {\n\t\treturn first == null;\n\t}\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Introduction/MyStack.java",
"content": "package Introduction;\n\nimport java.util.EmptyStackException;\n\npublic class MyStack {\n\tprivate static class StackNode {\n\t\tprivate T data;\n\t\tprivate StackNode next;\n\t\t\n\t\tpublic StackNode(T data) {\n\t\t\tthis.data = data;\n\t\t}\n\t\t\n\t\tpublic T getData() {\n\t\t\treturn data;\n\t\t}\n\t}\n\t\n\tprivate StackNode top;\n\n\tpublic T pop() {\n\t\tif (top == null) throw new EmptyStackException();\n\t\tT item = top.getData();\n\t\ttop = top.next;\n\t\treturn item;\n\t}\n\n\tpublic void push(T item) { \n\t\tStackNode t = new StackNode(item);\n\t\tt.next = top;\n\t\ttop = t;\n\t} \n\n\tpublic T peek() {\n\t\tif (top == null) throw new EmptyStackException();\n\t\treturn top.data;\n\t}\n\t\n\tpublic boolean isEmpty() {\n\t\treturn top == null;\n\t}\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Introduction/QueueTester.java",
"content": "package Introduction;\n\nimport java.util.LinkedList;\nimport java.util.NoSuchElementException;\nimport java.util.Queue;\n\nimport CtCILibrary.AssortedMethods;\n\npublic class QueueTester {\n\n\tpublic static void main(String[] args) {\n\t\tint[] array = AssortedMethods.randomArray(100, -100, 100);\n\t\tMyQueue queue1 = new MyQueue();\t\t\n\t\tQueue queue2 = new LinkedList();\n\t\t\n\t\tfor (int a : array) {\n\t\t\tif (a < 0) {\n\t\t\t\tint top1, top2;\n\t\t\t\ttry {\n\t\t\t\t\ttop1 = queue1.remove();\n\t\t\t\t} catch (NoSuchElementException ex) {\n\t\t\t\t\ttop1 = Integer.MIN_VALUE;\n\t\t\t\t}\n\t\t\t\ttry {\n\t\t\t\t\ttop2 = queue2.remove();\n\t\t\t\t} catch (NoSuchElementException ex) {\n\t\t\t\t\ttop2 = Integer.MIN_VALUE;\n\t\t\t\t}\n\t\t\t\tif (top1 != top2) {\n\t\t\t\t\tSystem.out.println(\"ERROR: mismatching tails\");\n\t\t\t\t} else {\n\t\t\t\t\tSystem.out.println(\"SUCCESS: matching tails: \" + top1);\n\t\t\t\t}\n\t\t\t} else {\n\t\t\t\tqueue1.add(a);\n\t\t\t\tqueue2.add(a);\n\t\t\t}\n\t\t}\n\t\t\n\t\twhile (!queue1.isEmpty() || !queue2.isEmpty()) {\n\t\t\tint top1, top2;\n\t\t\ttry {\n\t\t\t\ttop1 = queue1.remove();\n\t\t\t} catch (NoSuchElementException ex) {\n\t\t\t\ttop1 = Integer.MIN_VALUE;\n\t\t\t}\n\t\t\ttry {\n\t\t\t\ttop2 = queue2.remove();\n\t\t\t} catch (NoSuchElementException ex) {\n\t\t\t\ttop2 = Integer.MIN_VALUE;\n\t\t\t}\n\t\t\tif (top1 != top2) {\n\t\t\t\tSystem.out.println(\"ERROR: mismatching tails\");\n\t\t\t} else {\n\t\t\t\tSystem.out.println(\"SUCCESS: matching tails: \" + top1);\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Introduction/StackTester.java",
"content": "package Introduction;\n\nimport java.util.EmptyStackException;\nimport java.util.Stack;\n\nimport CtCILibrary.AssortedMethods;\n\npublic class StackTester {\n\n\tpublic static void main(String[] args) {\n\t\tint[] array = AssortedMethods.randomArray(100, -100, 100);\n\t\tMyStack stack1 = new MyStack();\t\t\n\t\tStack stack2 = new Stack();\n\t\t\n\t\tfor (int a : array) {\n\t\t\tif (a < 0) {\n\t\t\t\tint top1, top2;\n\t\t\t\ttry {\n\t\t\t\t\ttop1 = stack1.pop();\n\t\t\t\t} catch (EmptyStackException ex) {\n\t\t\t\t\ttop1 = Integer.MIN_VALUE;\n\t\t\t\t}\n\t\t\t\ttry {\n\t\t\t\t\ttop2 = stack2.pop();\n\t\t\t\t} catch (EmptyStackException ex) {\n\t\t\t\t\ttop2 = Integer.MIN_VALUE;\n\t\t\t\t}\n\t\t\t\tif (top1 != top2) {\n\t\t\t\t\tSystem.out.println(\"ERROR: mismatching tops\");\n\t\t\t\t} else {\n\t\t\t\t\tSystem.out.println(\"SUCCESS: matching tops: \" + top1);\n\t\t\t\t}\n\t\t\t} else {\n\t\t\t\tstack1.push(a);\n\t\t\t\tstack2.push(a);\n\t\t\t}\n\t\t}\n\t\t\n\t\twhile (!stack1.isEmpty() || !stack2.isEmpty()) {\n\t\t\tint top1, top2;\n\t\t\ttry {\n\t\t\t\ttop1 = stack1.pop();\n\t\t\t} catch (EmptyStackException ex) {\n\t\t\t\ttop1 = Integer.MIN_VALUE;\n\t\t\t}\n\t\t\ttry {\n\t\t\t\ttop2 = stack2.pop();\n\t\t\t} catch (EmptyStackException ex) {\n\t\t\t\ttop2 = Integer.MIN_VALUE;\n\t\t\t}\n\t\t\tif (top1 != top2) {\n\t\t\t\tSystem.out.println(\"ERROR: mismatching tops\");\n\t\t\t} else {\n\t\t\t\tSystem.out.println(\"SUCCESS: matching tops: \" + top1);\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_01_Three_in_One/FixedMultiStack.java",
"content": "package Q3_01_Three_in_One;\r\n\r\nimport java.util.EmptyStackException;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class FixedMultiStack {\r\n\tprivate int numberOfStacks = 3;\r\n\tprivate int stackCapacity;\r\n\tprivate int[] values;\r\n\tprivate int[] sizes;\r\n\t\r\n\tpublic FixedMultiStack(int stackSize) {\r\n\t\tstackCapacity = stackSize;\r\n\t\tvalues = new int[stackSize * numberOfStacks];\r\n\t\tsizes = new int[numberOfStacks];\r\n\t}\r\n\r\n\t/* Push value onto stack. */\r\n\tpublic void push(int stackNum, int value) throws FullStackException {\r\n\t\t/* Check that we have space for the next element */\r\n\t\tif (isFull(stackNum)) { \r\n\t\t\tthrow new FullStackException();\r\n\t\t}\r\n\t\t\r\n\t\t/* Increment stack pointer and then update top value. */\t\t\r\n\t\tsizes[stackNum]++;\r\n\t\tvalues[indexOfTop(stackNum)] = value;\t\r\n\t}\r\n\r\n\t/* Pop item from top stack. */\r\n\tpublic int pop(int stackNum) {\r\n\t\tif (isEmpty(stackNum)) {\r\n\t\t\tthrow new EmptyStackException();\r\n\t\t}\r\n\t\t\r\n\t\tint topIndex = indexOfTop(stackNum);\r\n\t\tint value = values[topIndex]; // Get top\r\n\t\tvalues[topIndex] = 0; // Clear \r\n\t\tsizes[stackNum]--; // Shrink\r\n\t\treturn value;\r\n\t}\r\n\r\n\t/* Return top element. */\r\n\tpublic int peek(int stackNum) {\r\n\t\tif (isEmpty(stackNum)) {\r\n\t\t\tthrow new EmptyStackException();\r\n\t\t}\t\t\r\n\t\treturn values[indexOfTop(stackNum)];\r\n\t}\r\n\r\n\t/* Return if stack is empty. */\r\n\tpublic boolean isEmpty(int stackNum) {\r\n\t\treturn sizes[stackNum] == 0;\r\n\t}\r\n\t\r\n\t/* Return if stack is full. */\r\n\tpublic boolean isFull(int stackNum) {\r\n\t\treturn sizes[stackNum] == stackCapacity;\r\n\t}\r\n\t\r\n\t/* Returns index of the top of the stack. */\r\n\tprivate int indexOfTop(int stackNum) {\r\n\t\tint offset = stackNum * stackCapacity;\r\n\t\tint size = sizes[stackNum];\r\n\t\treturn offset + size - 1;\r\n\t}\t\r\n\t\r\n\tpublic int[] getValues() {\r\n\t\treturn values;\r\n\t}\r\n\t\r\n\tpublic int[] getStackValues(int stackNum) {\r\n\t\tint[] items = new int[sizes[stackNum]];\r\n\t\tfor (int i = 0; i < items.length; i++) {\r\n\t\t\titems[i] = values[stackNum * stackCapacity + i];\r\n\t\t}\r\n\t\treturn items;\r\n\t}\r\n\t\r\n\tpublic String stackToString(int stackNum) {\r\n\t\tint[] items = getStackValues(stackNum);\r\n\t\treturn stackNum + \": \" + AssortedMethods.arrayToString(items);\r\n\t}\t\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_01_Three_in_One/FullStackException.java",
"content": "package Q3_01_Three_in_One;\n\npublic class FullStackException extends Exception {\n\tprivate static final long serialVersionUID = 1L;\n\n\tpublic FullStackException(){\n super();\n }\n\n public FullStackException(String message){\n super(message);\n }\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_01_Three_in_One/MultiStack.java",
"content": "package Q3_01_Three_in_One;\n\nimport java.util.EmptyStackException;\n\nimport CtCILibrary.AssortedMethods;\n\npublic class MultiStack {\n\t/* StackInfo is a simple class that holds a set of data about \n\t * each stack. It does not hold the actual items in the stack. \n\t * We could have done this with just a bunch of individual \n\t * variables, but that’s messy and doesn’t gain us much. */\n\tprivate class StackInfo {\n\t\tpublic int start, size, capacity;\n\t\tpublic StackInfo(int start, int capacity) {\n\t\t\tthis.start = start;\n\t\t\tthis.capacity = capacity;\n\t\t}\n\t\t\n\t\t/* Check if an index on the full array is within the stack\n\t\t * boundaries. The stack can wrap around to the start of \n\t\t * the array. */\n\t\tpublic boolean isWithinStackCapacity(int index) {\n\t\t\t/* If outside of bounds of array, return false. */\n\t\t\tif (index < 0 || index >= values.length) {\n\t\t\t\treturn false;\n\t\t\t}\n\t\t\t\n\t\t\t/* If index wraps around, adjust it. */\n\t\t\tint contiguousIndex = index < start ? index + values.length : index;\n\t\t\tint end = start + capacity;\n\t\t\treturn start <= contiguousIndex && contiguousIndex < end;\n\t\t}\n\t\t\n\t\tpublic int lastCapacityIndex() {\n\t\t\treturn adjustIndex(start + capacity - 1);\n\t\t}\n\t\t\n\t\tpublic int lastElementIndex() {\n\t\t\treturn adjustIndex(start + size - 1);\n\t\t}\t\t\n\t\t\n\t\tpublic boolean isFull() {\n\t\t\treturn size == capacity;\n\t\t}\n\t\t\n\t\tpublic boolean isEmpty() {\n\t\t\treturn size == 0;\n\t\t}\n\t}\n\t\n\tprivate StackInfo[] info;\n\tprivate int[] values;\n\t\n\tpublic MultiStack(int numberOfStacks, int defaultSize) {\n\t\t/* Create metadata for all the stacks. */\n\t\tinfo = new StackInfo[numberOfStacks];\n\t\tfor (int i = 0; i < numberOfStacks; i++) {\n\t\t\tinfo[i] = new StackInfo(defaultSize * i, defaultSize);\n\t\t}\n\t\tvalues = new int[numberOfStacks * defaultSize];\n\t}\t\n\t\n\t/* Returns the number of items actually present in stack. */\n\tpublic int numberOfElements() {\n\t\tint size = 0;\n\t\tfor (StackInfo sd : info) {\n\t\t\tsize += sd.size;\n\t\t}\n\t\treturn size;\n\t}\n\t\n\t/* Returns true is all the stacks are full. */\n\tpublic boolean allStacksAreFull() {\n\t\treturn numberOfElements() == values.length;\n\t}\n\t\n\t/* Adjust index to be within the range of 0 -> length - 1. */\n\tprivate int adjustIndex(int index) {\n\t\t/* Java's mod operator can return neg values. For example,\n\t\t * (-11 % 5) will return -1, not 4. We actually want the \n\t\t * value to be 4 (since we're wrapping around the index). \n\t\t */\n\t\tint max = values.length;\n\t\treturn ((index % max) + max) % max;\n\t}\n\t\n\t/* Get index after this index, adjusted for wrap around. */\n\tprivate int nextIndex(int index) {\n\t\treturn adjustIndex(index + 1);\n\t}\n\t\n\t/* Get index before this index, adjusted for wrap around. */\n\tprivate int previousIndex(int index) {\n\t\treturn adjustIndex(index - 1);\n\t}\n\t\n\t/* Shift items in stack over by one element. If we have \n\t * available capacity, then we'll end up shrinking the stack \n\t * by one element. If we don't have available capacity, then\n\t * we'll need to shift the next stack over too. */\n\tprivate void shift(int stackNum) {\n\t\tSystem.out.println(\"/// Shifting \" + stackNum);\n\t\tStackInfo stack = info[stackNum];\n\t\t\n\t\t/* If this stack is at its full capacity, then you need\n\t\t * to move the next stack over by one element. This stack\n\t\t * can now claim the freed index. */\n\t\tif (stack.size >= stack.capacity) {\n\t\t\tint nextStack = (stackNum + 1) % info.length;\n\t\t\tshift(nextStack); \n\t\t\tstack.capacity++; // claim index that next stack lost\n\t\t}\n\t\t\n\t\t/* Shift all elements in stack over by one. */\n\t\tint index = stack.lastCapacityIndex();\n\t\twhile (stack.isWithinStackCapacity(index)) {\n\t\t\tvalues[index] = values[previousIndex(index)];\n\t\t\tindex = previousIndex(index);\n\t\t}\n\t\t\n\t\t/* Adjust stack data. */\n\t\tvalues[stack.start] = 0; // Clear item\n\t\tstack.start = nextIndex(stack.start); // move start\n\t\tstack.capacity--; // Shrink capacity\n\t}\n\t\n\t/* Expand stack by shifting over other stacks */\n\tprivate void expand(int stackNum) {\n\t\tSystem.out.println(\"/// Expanding stack \" + stackNum);\n\t\t\n\t\tshift((stackNum + 1) % info.length);\n\t\tinfo[stackNum].capacity++;\n\t}\n\n\t/* Push value onto stack num, shifting/expanding stacks as \n\t * necessary. Throws exception if all stacks are full. */\n\tpublic void push(int stackNum, int value) throws FullStackException {\n\t\tSystem.out.println(\"/// Pushing stack \" + stackNum + \": \" + value);\n\t\tif (allStacksAreFull()) {\n\t\t\tthrow new FullStackException();\n\t\t}\n\t\t\n\t\t/* If this stack is full, expand it. */\n\t\tStackInfo stack = info[stackNum];\n\t\tif (stack.isFull()) {\n\t\t\texpand(stackNum);\n\t\t}\n\t\t\n\t\t/* Find the index of the top element in the array + 1, \n\t\t * and increment the stack pointer */\t\n\t\tstack.size++;\t\n\t\tvalues[stack.lastElementIndex()] = value;\t\n\t}\n\n\t/* Remove value from stack. */\n\tpublic int pop(int stackNum) throws Exception {\n\t\tSystem.out.println(\"/// Popping stack \" + stackNum);\n\t\tStackInfo stack = info[stackNum];\t\t\n\t\tif (stack.isEmpty()) {\n\t\t\tthrow new EmptyStackException();\n\t\t}\n\n\t\t/* Remove last element. */\n\t\tint value = values[stack.lastElementIndex()];\n\t\tvalues[stack.lastElementIndex()] = 0; // Clear item\n\t\tstack.size--; // Shrink size\n\t\treturn value;\n\t}\n\n\t/* Get top element of stack.*/\n\tpublic int peek(int stackNum) {\n\t\tStackInfo stack = info[stackNum];\t\t\t\n\t\treturn values[stack.lastElementIndex()];\n\t}\n\t\n\tpublic int[] getValues() {\n\t\treturn values;\n\t}\n\t\n\tpublic int[] getStackValues(int stackNum) {\n\t\tStackInfo stack = info[stackNum];\n\t\tint[] items = new int[stack.size];\n\t\tfor (int i = 0; i < items.length; i++) {\n\t\t\titems[i] = values[adjustIndex(stack.start + i)];\n\t\t}\n\t\treturn items;\n\t}\n\t\n\tpublic String stackToString(int stackNum) {\n\t\tint[] items = getStackValues(stackNum);\n\t\treturn stackNum + \": \" + AssortedMethods.arrayToString(items);\n\t}\n}\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_01_Three_in_One/QuestionA.java",
"content": "package Q3_01_Three_in_One;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionA {\r\n\tpublic static void printStacks(FixedMultiStack stacks) {\r\n\t\tSystem.out.println(AssortedMethods.arrayToString(stacks.getValues()));\r\n\t}\r\n\t\r\n\tpublic static void main(String [] args) throws Exception {\r\n\t\tFixedMultiStack stacks = new FixedMultiStack(4);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 10);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(1, 20);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 30);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(1, 21);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 11);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 12);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.pop(0);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(2, 31);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(0, 13);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(1, 22);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(2, 31);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 32);\r\n\t\tprintStacks(stacks);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_01_Three_in_One/QuestionB.java",
"content": "package Q3_01_Three_in_One;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionB {\r\n\tpublic static void printStacks(MultiStack stacks) {\r\n\t\t//System.out.println(stacks.stackToString(0));\r\n\t\t//System.out.println(stacks.stackToString(1));\r\n\t\t//System.out.println(stacks.stackToString(2));\r\n\t\tSystem.out.println(AssortedMethods.arrayToString(stacks.getValues()));\r\n\t}\r\n\t\r\n\tpublic static void main(String [] args) throws Exception {\t\r\n\t\tMultiStack stacks = new MultiStack(3, 4);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 10);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(1, 20);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 30);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(1, 21);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 11);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(0, 12);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.pop(0);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(2, 31);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(0, 13);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(1, 22);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.push(2, 31);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 32);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 33);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 34);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tstacks.pop(1);\r\n\t\tprintStacks(stacks);\r\n\t\tstacks.push(2, 35);\r\n\t\tprintStacks(stacks);\r\n\t\t\r\n\t\tSystem.out.println(\"Final Stack: \" + AssortedMethods.arrayToString(stacks.getValues()));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_02_Stack_Min/NodeWithMin.java",
"content": "package Q3_02_Stack_Min;\r\n\r\nclass NodeWithMin {\r\n public int value;\r\n public int min;\r\n public NodeWithMin(int v, int min){\r\n value = v;\r\n this.min = min;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_02_Stack_Min/Question.java",
"content": "package Q3_02_Stack_Min;\r\n\r\npublic class Question {\r\n\tpublic static void main(String[] args) {\r\n\t\tStackWithMin stack = new StackWithMin();\r\n\t\tStackWithMin2 stack2 = new StackWithMin2();\r\n\t\tint[] array = {2, 1, 3, 1};\r\n\t\tfor (int value : array) {\r\n\t\t\tstack.push(value);\r\n\t\t\tstack2.push(value);\r\n\t\t\tSystem.out.print(value + \", \");\r\n\t\t}\r\n\t\tSystem.out.println('\\n');\r\n\t\tfor (int i = 0; i < array.length; i++) {\r\n\t\t\tSystem.out.println(\"Popped \" + stack.pop().value + \", \" + stack2.pop());\r\n\t\t\tSystem.out.println(\"New min is \" + stack.min() + \", \" + stack2.min());\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_02_Stack_Min/StackWithMin.java",
"content": "package Q3_02_Stack_Min;\r\n\r\nimport java.util.Stack;\r\n\r\npublic class StackWithMin extends Stack {\r\n public void push(int value) {\r\n int newMin = Math.min(value, min());\r\n super.push(new NodeWithMin(value, newMin));\r\n }\r\n \r\n public int min() {\r\n \tif (this.isEmpty()) {\r\n \t\treturn Integer.MAX_VALUE;\r\n \t} else {\r\n \t\treturn peek().min;\r\n \t}\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_02_Stack_Min/StackWithMin2.java",
"content": "package Q3_02_Stack_Min;\r\n\r\nimport java.util.Stack;\r\n\r\npublic class StackWithMin2 extends Stack {\r\n\tStack s2;\r\n\t\r\n\tpublic StackWithMin2() {\r\n\t\ts2 = new Stack();\t\t\r\n\t}\r\n\t\r\n\tpublic void push(int value){\r\n\t\tif (value <= min()) {\r\n\t\t\ts2.push(value);\r\n\t\t}\r\n\t\tsuper.push(value);\r\n\t}\r\n\t\r\n\tpublic Integer pop() {\r\n\t\tint value = super.pop();\r\n\t\tif (value == min()) {\r\n\t\t\ts2.pop();\t\t\t\r\n\t\t}\r\n\t\treturn value;\r\n\t}\r\n\t\r\n\tpublic int min() {\r\n\t\tif (s2.isEmpty()) {\r\n\t\t\treturn Integer.MAX_VALUE;\r\n\t\t} else {\r\n\t\t\treturn s2.peek();\r\n\t\t}\r\n\t}\r\n}\r\n\r\n\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_03_Stack_of_Plates/Node.java",
"content": "package Q3_03_Stack_of_Plates;\r\n\r\npublic class Node {\r\n\tpublic Node above;\r\n\tpublic Node below;\r\n\tpublic int value;\r\n\tpublic Node(int value) {\r\n\t\tthis.value = value;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_03_Stack_of_Plates/Question.java",
"content": "package Q3_03_Stack_of_Plates;\r\n\r\npublic class Question {\r\n\tpublic static void main(String[] args) {\r\n\t\tint capacity_per_substack = 5;\r\n\t\tSetOfStacks set = new SetOfStacks(capacity_per_substack);\r\n\t\tfor (int i = 0; i < 34; i++) {\r\n\t\t\tset.push(i);\r\n\t\t}\r\n\t\tfor (int i = 0; i < 35; i++) {\r\n\t\t\tSystem.out.println(\"Popped \" + set.pop());\r\n\t\t}\t\t\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_03_Stack_of_Plates/SetOfStacks.java",
"content": "package Q3_03_Stack_of_Plates;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.EmptyStackException;\r\n\r\npublic class SetOfStacks {\r\n\tArrayList stacks = new ArrayList();\r\n\tpublic int capacity;\r\n\t\r\n\tpublic SetOfStacks(int capacity) { \r\n\t\tthis.capacity = capacity; \r\n\t}\r\n\t\r\n\tpublic Stack getLastStack() {\r\n\t\tif (stacks.size() == 0) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\treturn stacks.get(stacks.size() - 1);\r\n\t}\r\n\t\r\n\tpublic void push(int v) {\r\n\t\tStack last = getLastStack();\r\n\t\tif (last != null && !last.isFull()) { // add to last\r\n\t\t\tlast.push(v);\r\n\t\t} else { // must create new stack\r\n\t\t\tStack stack = new Stack(capacity);\r\n\t\t\tstack.push(v);\r\n\t\t\tstacks.add(stack);\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic int pop() {\r\n\t\tStack last = getLastStack();\r\n\t\tif (last == null) throw new EmptyStackException();\r\n\t\tint v = last.pop();\r\n\t\tif (last.size == 0) {\r\n\t\t\tstacks.remove(stacks.size() - 1);\r\n\t\t}\r\n\t\treturn v;\r\n\t}\r\n\t\r\n\tpublic int popAt(int index) {\r\n\t\treturn leftShift(index, true);\r\n\t}\r\n\t\r\n\tpublic int leftShift(int index, boolean removeTop) {\r\n\t\tStack stack = stacks.get(index);\r\n\t\tint removed_item;\r\n\t\tif (removeTop) removed_item = stack.pop();\r\n\t\telse removed_item = stack.removeBottom();\r\n\t\tif (stack.isEmpty()) {\r\n\t\t\tstacks.remove(index);\r\n\t\t} else if (stacks.size() > index + 1) {\r\n\t\t\tint v = leftShift(index + 1, false);\r\n\t\t\tstack.push(v);\r\n\t\t}\r\n\t\treturn removed_item;\r\n\t}\r\n\t\r\n\tpublic boolean isEmpty() {\r\n\t\tStack last = getLastStack();\r\n\t\treturn last == null || last.isEmpty();\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_03_Stack_of_Plates/Stack.java",
"content": "package Q3_03_Stack_of_Plates;\r\n\r\nimport java.util.EmptyStackException;\r\n\r\npublic class Stack {\r\n\tprivate int capacity;\r\n\tpublic Node top;\r\n\tpublic Node bottom;\r\n\tpublic int size = 0;\r\n\t\r\n\tpublic Stack(int capacity) { \r\n\t\tthis.capacity = capacity; \r\n\t}\r\n\t\r\n\tpublic boolean isFull() { \r\n\t\treturn capacity == size; \r\n\t}\r\n\t\r\n\tpublic void join(Node above, Node below) {\r\n\t\tif (below != null) below.above = above;\r\n\t\tif (above != null) above.below = below;\r\n\t}\r\n\t\r\n\tpublic boolean push(int v) {\r\n\t\tif (size >= capacity) return false;\r\n\t\tsize++;\r\n\t\tNode n = new Node(v);\r\n\t\tif (size == 1) bottom = n;\r\n\t\tjoin(n, top);\r\n\t\ttop = n;\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic int pop() {\r\n\t\tif (top == null) throw new EmptyStackException();\r\n\t\tNode t = top;\r\n\t\ttop = top.below;\r\n\t\tsize--;\r\n\t\treturn t.value;\r\n\t}\r\n\t\r\n\tpublic boolean isEmpty() { \r\n\t\treturn size == 0; \r\n\t}\r\n\t\r\n\tpublic int removeBottom() {\r\n\t\tNode b = bottom;\r\n\t\tbottom = bottom.above;\r\n\t\tif (bottom != null) bottom.below = null;\r\n\t\tsize--;\r\n\t\treturn b.value;\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_04_Queue_via_Stacks/MyQueue.java",
"content": "package Q3_04_Queue_via_Stacks;\r\n\r\nimport java.util.Stack;\r\n\r\npublic class MyQueue {\r\n\tStack stackNewest, stackOldest;\r\n\t\r\n\tpublic MyQueue() {\r\n\t\tstackNewest = new Stack();\r\n\t\tstackOldest = new Stack();\r\n\t}\r\n\t\r\n\tpublic int size() {\r\n\t\treturn stackNewest.size() + stackOldest.size();\r\n\t}\r\n\t\r\n\tpublic void add(T value) {\r\n\t\t// Push onto stack1\r\n\t\tstackNewest.push(value);\r\n\t}\r\n\t\r\n\t/* Move elements from stackNewest into stackOldest. This is usually done so that we can\r\n\t * do operations on stackOldest.\r\n\t */\r\n\tprivate void shiftStacks() {\r\n\t\tif (stackOldest.isEmpty()) { \r\n\t\t\twhile (!stackNewest.isEmpty()) {\r\n\t\t\t\tstackOldest.push(stackNewest.pop());\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic T peek() {\r\n\t\tshiftStacks();\r\n\t\treturn stackOldest.peek(); // retrieve the oldest item.\r\n\t}\r\n\t\r\n\tpublic T remove() {\r\n\t\tshiftStacks();\r\n\t\treturn stackOldest.pop(); // pop the oldest item.\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_04_Queue_via_Stacks/Question.java",
"content": "package Q3_04_Queue_via_Stacks;\r\n\r\nimport java.util.LinkedList;\r\nimport java.util.Queue;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\tpublic static void main(String[] args) {\r\n\t\tMyQueue my_queue = new MyQueue();\t\r\n\t\t\r\n\t\t// Let's test our code against a \"real\" queue\r\n\t\tQueue test_queue = new LinkedList();\r\n\t\t\r\n\t\tfor (int i = 0; i < 100; i++) {\r\n\t\t\tint choice = AssortedMethods.randomIntInRange(0, 10);\r\n\t\t\tif (choice <= 5) { // enqueue\r\n\t\t\t\tint element = AssortedMethods.randomIntInRange(1, 10);\r\n\t\t\t\ttest_queue.add(element);\r\n\t\t\t\tmy_queue.add(element);\r\n\t\t\t\tSystem.out.println(\"Enqueued \" + element);\r\n\t\t\t} else if (test_queue.size() > 0) {\r\n\t\t\t\tint top1 = test_queue.remove();\r\n\t\t\t\tint top2 = my_queue.remove();\r\n\t\t\t\tif (top1 != top2) { // Check for error\r\n\t\t\t\t\tSystem.out.println(\"******* FAILURE - DIFFERENT TOPS: \" + top1 + \", \" + top2);\r\n\t\t\t\t} \r\n\t\t\t\tSystem.out.println(\"Dequeued \" + top1);\r\n\t\t\t}\r\n\t\t\t\r\n\t\t\tif (test_queue.size() == my_queue.size()) {\r\n\t\t\t\tif (test_queue.size() > 0 && test_queue.peek() != my_queue.peek()) {\r\n\t\t\t\t\tSystem.out.println(\"******* FAILURE - DIFFERENT TOPS: \" + test_queue.peek() + \", \" + my_queue.peek() + \" ******\");\r\n\t\t\t\t}\r\n\t\t\t} else {\r\n\t\t\t\tSystem.out.println(\"******* FAILURE - DIFFERENT SIZES ******\");\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_05_Sort_Stack/Question.java",
"content": "package Q3_05_Sort_Stack;\r\n\r\nimport java.util.Stack;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\tpublic static Stack mergesort(Stack inStack) {\r\n\t\tif (inStack.size() <= 1) {\r\n\t\t\treturn inStack;\r\n\t\t}\r\n\r\n\t\tStack left = new Stack();\r\n\t\tStack right = new Stack();\r\n\t\tint count = 0;\r\n\t\twhile (inStack.size() != 0) {\r\n\t\t\tcount++;\r\n\t\t\tif (count % 2 == 0) {\r\n\t\t\t\tleft.push(inStack.pop());\r\n\t\t\t} else {\r\n\t\t\t\tright.push(inStack.pop());\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\tleft = mergesort(left);\r\n\t\tright = mergesort(right);\r\n\r\n\t\twhile (left.size() > 0 || right.size() > 0) {\r\n\t\t\tif (left.size() == 0) {\r\n\t\t\t\tinStack.push(right.pop());\r\n\t\t\t} else if (right.size() == 0) {\r\n\t\t\t\tinStack.push(left.pop());\r\n\t\t\t} else if (right.peek().compareTo(left.peek()) <= 0) {\r\n\t\t\t\tinStack.push(left.pop());\r\n\t\t\t} else {\r\n\t\t\t\tinStack.push(right.pop());\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\tStack reverseStack = new Stack();\r\n\t\twhile (inStack.size() > 0) {\r\n\t\t\treverseStack.push(inStack.pop());\r\n\t\t}\r\n\r\n\t\treturn reverseStack;\r\n\t}\r\n\t\r\n\tpublic static void sort(Stack s) {\r\n\t\tStack r = new Stack();\r\n\t\twhile(!s.isEmpty()) {\r\n\t\t\t/* Insert each element in s in sorted order into r. */\r\n\t\t\tint tmp = s.pop();\r\n\t\t\twhile(!r.isEmpty() && r.peek() > tmp) {\r\n\t\t\t\ts.push(r.pop());\r\n\t\t\t}\r\n\t\t\tr.push(tmp);\r\n\t\t}\r\n\t\t\r\n\t\t/* Copy the elements back. */\r\n\t\twhile (!r.isEmpty()) {\r\n\t\t\ts.push(r.pop());\r\n\t\t}\r\n\t}\r\n\t\t\r\n\tpublic static void main(String [] args) {\r\n\t\tStack s = new Stack();\r\n\t\tfor (int i = 0; i < 10; i++) {\r\n\t\t\tint r = AssortedMethods.randomIntInRange(0, 1000);\r\n\t\t\ts.push(r);\r\n\t\t}\r\n\t\t\r\n\t\tsort(s);\r\n\t\t\r\n\t\twhile(!s.isEmpty()) {\r\n\t\t\tSystem.out.println(s.pop());\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_06_Animal_Shelter/Animal.java",
"content": "package Q3_06_Animal_Shelter;\r\n\r\npublic abstract class Animal {\r\n\tprivate int order; \r\n\tprotected String name;\r\n\tpublic Animal(String n) {\r\n\t\tname = n;\r\n\t}\r\n\t\r\n\tpublic abstract String name();\r\n\t\r\n\tpublic void setOrder(int ord) {\r\n\t\torder = ord;\r\n\t}\r\n\t\r\n\tpublic int getOrder() {\r\n\t\treturn order;\r\n\t}\r\n\t\r\n\tpublic boolean isOlderThan(Animal a) {\r\n\t\treturn this.order < a.getOrder();\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_06_Animal_Shelter/AnimalQueue.java",
"content": "package Q3_06_Animal_Shelter;\r\n\r\nimport java.util.LinkedList;\r\n\r\npublic class AnimalQueue {\r\n\tLinkedList dogs = new LinkedList();\r\n\tLinkedList cats = new LinkedList();\r\n\tprivate int order = 0;\r\n\t\r\n\tpublic void enqueue(Animal a) {\r\n\t\ta.setOrder(order);\r\n\t\torder++;\r\n\t\tif (a instanceof Dog) {\r\n\t\t\tdogs.addLast((Dog) a);\r\n\t\t} else if (a instanceof Cat) {\r\n\t\t\tcats.addLast((Cat)a);\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic Animal dequeueAny() {\r\n\t\tif (dogs.size() == 0) {\r\n\t\t\treturn dequeueCats();\r\n\t\t} else if (cats.size() == 0) {\r\n\t\t\treturn dequeueDogs();\r\n\t\t}\r\n\t\tDog dog = dogs.peek();\r\n\t\tCat cat = cats.peek();\r\n\t\tif (dog.isOlderThan(cat)) {\r\n\t\t\treturn dogs.poll();\r\n\t\t} else {\r\n\t\t\treturn cats.poll();\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic Animal peek() {\r\n\t\tif (dogs.size() == 0) {\r\n\t\t\treturn cats.peek();\r\n\t\t} else if (cats.size() == 0) {\r\n\t\t\treturn dogs.peek();\r\n\t\t}\r\n\t\tDog dog = dogs.peek();\r\n\t\tCat cat = cats.peek();\r\n\t\tif (dog.isOlderThan(cat)) {\r\n\t\t\treturn dog;\r\n\t\t} else {\r\n\t\t\treturn cat;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic int size() {\r\n\t\treturn dogs.size() + cats.size();\r\n\t}\r\n\t\r\n\tpublic Dog dequeueDogs() {\r\n\t\treturn dogs.poll();\r\n\t}\r\n\t\r\n\tpublic Dog peekDogs() {\r\n\t\treturn dogs.peek();\r\n\t}\r\n\t\r\n\tpublic Cat dequeueCats() {\r\n\t\treturn cats.poll();\r\n\t}\r\n\t\r\n\tpublic Cat peekCats() {\r\n\t\treturn cats.peek();\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_06_Animal_Shelter/Cat.java",
"content": "package Q3_06_Animal_Shelter;\r\n\r\npublic class Cat extends Animal {\r\n\tpublic Cat(String n) {\r\n\t\tsuper(n);\r\n\t}\r\n\t\r\n\tpublic String name() {\r\n\t\treturn \"Cat: \" + name;\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_06_Animal_Shelter/Dog.java",
"content": "package Q3_06_Animal_Shelter;\r\n\r\npublic class Dog extends Animal {\r\n\tpublic Dog(String n) {\r\n\t\tsuper(n);\r\n\t}\r\n\t\r\n\tpublic String name() {\r\n\t\treturn \"Dog: \" + name;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 03. Stacks and Queues/Q3_06_Animal_Shelter/Question.java",
"content": "package Q3_06_Animal_Shelter;\r\n\r\npublic class Question {\r\n\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tAnimalQueue animals = new AnimalQueue();\r\n\t\tanimals.enqueue(new Cat(\"Callie\"));\r\n\t\tanimals.enqueue(new Cat(\"Kiki\"));\r\n\t\tanimals.enqueue(new Dog(\"Fido\"));\r\n\t\tanimals.enqueue(new Dog(\"Dora\"));\r\n\t\tanimals.enqueue(new Cat(\"Kari\"));\r\n\t\tanimals.enqueue(new Dog(\"Dexter\"));\r\n\t\tanimals.enqueue(new Dog(\"Dobo\"));\r\n\t\tanimals.enqueue(new Cat(\"Copa\"));\r\n\t\t\r\n\t\tSystem.out.println(animals.dequeueAny().name());\t\r\n\t\tSystem.out.println(animals.dequeueAny().name());\t\r\n\t\tSystem.out.println(animals.dequeueAny().name());\t\r\n\t\t\r\n\t\tanimals.enqueue(new Dog(\"Dapa\"));\r\n\t\tanimals.enqueue(new Cat(\"Kilo\"));\r\n\t\t\r\n\t\twhile (animals.size() != 0) {\r\n\t\t\tSystem.out.println(animals.dequeueAny().name());\t\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Introduction/Traversals.java",
"content": "package Introduction;\n\nimport CtCILibrary.TreeNode;\n\npublic class Traversals {\n\tpublic static void visit(TreeNode node) {\n\t\tif (node != null) {\n\t\t\tSystem.out.println(node.data);\n\t\t}\n\t}\n\t\n\tpublic static void inOrderTraversal(TreeNode node) {\n\t\tif (node != null) {\n\t\t\tinOrderTraversal(node.left);\n\t\t\tvisit(node);\n\t\t\tinOrderTraversal(node.right);\n\t\t}\n\t}\n\t\n\tpublic static void preOrderTraversal(TreeNode node) {\n\t\tif (node != null) {\n\t\t\tvisit(node);\n\t\t\tinOrderTraversal(node.left);\n\t\t\tinOrderTraversal(node.right);\n\t\t}\n\t}\n\t\n\tpublic static void postOrderTraversal(TreeNode node) {\n\t\tif (node != null) {\n\t\t\tinOrderTraversal(node.left);\n\t\t\tinOrderTraversal(node.right);\n\t\t\tvisit(node);\n\t\t}\n\t}\t\n\t\n\tpublic static void main(String[] args) {\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\n\t\t\n\t\t// We needed this code for other files, so check out the code in the library\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\n\t\tinOrderTraversal(root);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_01_Route_Between_Nodes/Graph.java",
"content": "package Q4_01_Route_Between_Nodes;\r\n\r\npublic class Graph {\r\n\tpublic static int MAX_VERTICES = 6;\r\n\tprivate Node vertices[];\r\n\tpublic int count;\r\n\tpublic Graph() {\r\n\t\tvertices = new Node[MAX_VERTICES];\r\n\t\tcount = 0;\r\n }\r\n\t\r\n public void addNode(Node x) {\r\n\t\tif (count < vertices.length) {\r\n\t\t\tvertices[count] = x;\r\n\t\t\tcount++;\r\n\t\t} else {\r\n\t\t\tSystem.out.print(\"Graph full\");\r\n\t\t}\r\n }\r\n \r\n public Node[] getNodes() {\r\n return vertices;\r\n }\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_01_Route_Between_Nodes/Node.java",
"content": "package Q4_01_Route_Between_Nodes;\r\n\r\nclass Node {\r\n private Node adjacent[];\r\n public int adjacentCount;\r\n private String vertex;\r\n public Question.State state;\r\n public Node(String vertex, int adjacentLength) {\r\n this.vertex = vertex; \r\n adjacentCount = 0; \r\n adjacent = new Node[adjacentLength];\r\n }\r\n \r\n public void addAdjacent(Node x) {\r\n if (adjacentCount < adjacent.length) {\r\n this.adjacent[adjacentCount] = x;\r\n adjacentCount++;\r\n } else {\r\n System.out.print(\"No more adjacent can be added\");\r\n }\r\n }\r\n public Node[] getAdjacent() {\r\n return adjacent;\r\n }\r\n public String getVertex() {\r\n return vertex;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_01_Route_Between_Nodes/Question.java",
"content": "package Q4_01_Route_Between_Nodes;\r\n\r\nimport java.util.LinkedList;\r\n\r\npublic class Question {\r\n\tpublic enum State {\r\n\t\tUnvisited, Visited, Visiting;\r\n\t} \r\n\r\n\tpublic static void main(String a[])\r\n\t{\r\n\t\tGraph g = createNewGraph();\r\n\t\tNode[] n = g.getNodes();\r\n\t\tNode start = n[3];\r\n\t\tNode end = n[5];\r\n\t\tSystem.out.println(search(g, start, end));\r\n\t}\r\n\t\r\n\tpublic static Graph createNewGraph()\r\n\t{\r\n\t\tGraph g = new Graph(); \r\n\t\tNode[] temp = new Node[6];\r\n\r\n\t\ttemp[0] = new Node(\"a\", 3);\r\n\t\ttemp[1] = new Node(\"b\", 0);\r\n\t\ttemp[2] = new Node(\"c\", 0);\r\n\t\ttemp[3] = new Node(\"d\", 1);\r\n\t\ttemp[4] = new Node(\"e\", 1);\r\n\t\ttemp[5] = new Node(\"f\", 0);\r\n\r\n\t\ttemp[0].addAdjacent(temp[1]);\r\n\t\ttemp[0].addAdjacent(temp[2]);\r\n\t\ttemp[0].addAdjacent(temp[3]);\r\n\t\ttemp[3].addAdjacent(temp[4]);\r\n\t\ttemp[4].addAdjacent(temp[5]);\r\n\t\tfor (int i = 0; i < 6; i++) {\r\n\t\t\tg.addNode(temp[i]);\r\n\t\t}\r\n\t\treturn g;\r\n\t}\r\n\r\n public static boolean search(Graph g,Node start,Node end) { \r\n LinkedList q = new LinkedList();\r\n for (Node u : g.getNodes()) {\r\n u.state = State.Unvisited;\r\n }\r\n start.state = State.Visiting;\r\n q.add(start);\r\n Node u;\r\n while(!q.isEmpty()) {\r\n u = q.removeFirst();\r\n if (u != null) {\r\n\t for (Node v : u.getAdjacent()) {\r\n\t if (v.state == State.Unvisited) {\r\n\t if (v == end) {\r\n\t return true;\r\n\t } else {\r\n\t v.state = State.Visiting;\r\n\t q.add(v);\r\n\t }\r\n\t }\r\n\t }\r\n\t u.state = State.Visited;\r\n }\r\n }\r\n return false;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_02_Minimal_Tree/Question.java",
"content": "package Q4_02_Minimal_Tree;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class Question {\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\t\r\n\t\t// We needed this code for other files, so check out the code in the library\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tSystem.out.println(\"Root? \" + root.data);\r\n\t\tSystem.out.println(\"Created BST? \" + root.isBST());\r\n\t\tSystem.out.println(\"Height: \" + root.height());\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_03_List_of_Depths/QuestionBFS.java",
"content": "package Q4_03_List_of_Depths;\r\n\r\nimport CtCILibrary.*;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.Iterator;\r\nimport java.util.LinkedList;\r\n\r\npublic class QuestionBFS {\r\n\r\n\tpublic static ArrayList> createLevelLinkedList(TreeNode root) {\r\n\t\tArrayList> result = new ArrayList>();\r\n\t\t\r\n\t\t/* \"Visit\" the root */\r\n\t\tLinkedList current = new LinkedList();\r\n\t\tif (root != null) {\r\n\t\t\tcurrent.add(root);\r\n\t\t}\r\n\t\t\r\n\t\twhile (current.size() > 0) {\r\n\t\t\tresult.add(current); // Add previous level\r\n\t\t\tLinkedList parents = current; // Go to next level\r\n\t\t\tcurrent = new LinkedList(); \r\n\t\t\tfor (TreeNode parent : parents) {\r\n\t\t\t\t/* Visit the children */\r\n\t\t\t\tif (parent.left != null) {\r\n\t\t\t\t\tcurrent.add(parent.left);\r\n\t\t\t\t}\r\n\t\t\t\tif (parent.right != null) {\r\n\t\t\t\t\tcurrent.add(parent.right);\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\treturn result;\r\n\t}\r\n\t\r\n\tpublic static void printResult(ArrayList> result){\r\n\t\tint depth = 0;\r\n\t\tfor(LinkedList entry : result) {\r\n\t\t\tIterator i = entry.listIterator();\r\n\t\t\tSystem.out.print(\"Link list at depth \" + depth + \":\");\r\n\t\t\twhile(i.hasNext()){\r\n\t\t\t\tSystem.out.print(\" \" + ((TreeNode)i.next()).data);\r\n\t\t\t}\r\n\t\t\tSystem.out.println();\r\n\t\t\tdepth++;\r\n\t\t}\r\n\t}\r\n\t\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] nodes_flattened = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = AssortedMethods.createTreeFromArray(nodes_flattened);\r\n\t\tArrayList> list = createLevelLinkedList(root);\r\n\t\tprintResult(list);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_03_List_of_Depths/QuestionDFS.java",
"content": "package Q4_03_List_of_Depths;\r\n\r\nimport CtCILibrary.*;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.Iterator;\r\nimport java.util.LinkedList;\r\n\r\npublic class QuestionDFS {\r\n\r\n\tpublic static void createLevelLinkedList(TreeNode root, ArrayList> lists, int level) {\r\n\t\tif (root == null) return;\r\n\t\tLinkedList list = null;\r\n\t\tif (lists.size() == level) { // Level not contained in list\r\n\t\t\tlist = new LinkedList();\r\n\t\t\t/* Levels are always traversed in order. So, if this is the first time we've visited level i,\r\n\t\t\t * we must have seen levels 0 through i - 1. We can therefore safely add the level at the end. */\r\n\t\t\tlists.add(list); \r\n\t\t} else {\r\n\t\t\tlist = lists.get(level);\r\n\t\t}\r\n\t\tlist.add(root);\r\n\t\tcreateLevelLinkedList(root.left, lists, level + 1);\r\n\t\tcreateLevelLinkedList(root.right, lists, level + 1);\r\n\t}\r\n\t\r\n\tpublic static ArrayList> createLevelLinkedList(TreeNode root) {\r\n\t\tArrayList> lists = new ArrayList>();\r\n\t\tcreateLevelLinkedList(root, lists, 0);\r\n\t\treturn lists;\r\n\t}\t\r\n\t\r\n\tpublic static void printResult(ArrayList> result){\r\n\t\tint depth = 0;\r\n\t\tfor(LinkedList entry : result) {\r\n\t\t\tIterator i = entry.listIterator();\r\n\t\t\tSystem.out.print(\"Link list at depth \" + depth + \":\");\r\n\t\t\twhile(i.hasNext()){\r\n\t\t\t\tSystem.out.print(\" \" + ((TreeNode)i.next()).data);\r\n\t\t\t}\r\n\t\t\tSystem.out.println();\r\n\t\t\tdepth++;\r\n\t\t}\r\n\t}\r\n\t\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] nodes_flattened = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = AssortedMethods.createTreeFromArray(nodes_flattened);\r\n\t\tArrayList> list = createLevelLinkedList(root);\r\n\t\tprintResult(list);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_04_Check_Balanced/QuestionBrute.java",
"content": "package Q4_04_Check_Balanced;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionBrute {\r\n\t\r\n\tpublic static int getHeight(TreeNode root) {\r\n\t\tif (root == null) {\r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\treturn Math.max(getHeight(root.left), getHeight(root.right)) + 1;\r\n\t}\r\n\t\t\r\n\tpublic static boolean isBalanced(TreeNode root) {\r\n\t\tif (root == null) {\r\n\t\t\treturn true;\r\n\t\t}\r\n\t\tint heightDiff = getHeight(root.left) - getHeight(root.right);\r\n\t\tif (Math.abs(heightDiff) > 1) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\telse {\r\n\t\t\treturn isBalanced(root.left) && isBalanced(root.right);\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\t// Create balanced tree\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tSystem.out.println(\"Root? \" + root.data);\r\n\t\tSystem.out.println(\"Is balanced? \" + isBalanced(root));\r\n\t\t\r\n\t\t// Could be balanced, actually, but it's very unlikely...\r\n\t\tTreeNode unbalanced = new TreeNode(10);\r\n\t\tfor (int i = 0; i < 10; i++) {\r\n\t\t\tunbalanced.insertInOrder(AssortedMethods.randomIntInRange(0, 100));\r\n\t\t}\r\n\t\tSystem.out.println(\"Root? \" + unbalanced.data);\r\n\t\tSystem.out.println(\"Is balanced? \" + isBalanced(unbalanced));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_04_Check_Balanced/QuestionImproved.java",
"content": "package Q4_04_Check_Balanced;\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionImproved {\r\n\t\t\r\n\tpublic static int checkHeight(TreeNode root) {\r\n\t\tif (root == null) {\r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\tint leftHeight = checkHeight(root.left);\r\n\t\tif (leftHeight == Integer.MIN_VALUE) return Integer.MIN_VALUE; // Propagate error up\r\n\t\t\r\n\t\tint rightHeight = checkHeight(root.right);\r\n\t\tif (rightHeight == Integer.MIN_VALUE) return Integer.MIN_VALUE; // Propagate error up\r\n\t\t\r\n\t\tint heightDiff = leftHeight - rightHeight;\r\n\t\tif (Math.abs(heightDiff) > 1) {\r\n\t\t\treturn Integer.MIN_VALUE; // Found error -> pass it back\r\n\t\t} else {\r\n\t\t\treturn Math.max(leftHeight, rightHeight) + 1;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static boolean isBalanced(TreeNode root) {\r\n\t\treturn checkHeight(root) != Integer.MIN_VALUE;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\t// Create balanced tree\r\n\t\tint[] array = {0, 1, 2, 3, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\r\n\t\t\r\n\t\tSystem.out.println(\"Is balanced? \" + isBalanced(root));\r\n\t\t\r\n\t\troot.insertInOrder(4); // Add 4 to make it unbalanced\r\n\r\n\t\tSystem.out.println(\"Is balanced? \" + isBalanced(root));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_05_Validate_BST/IntWrapper.java",
"content": "package Q4_05_Validate_BST;\r\n\r\npublic class IntWrapper {\r\n\tpublic IntWrapper(int m) {\r\n\t\tdata = m;\r\n\t}\r\n\tpublic int data;\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_05_Validate_BST/Question.java",
"content": "package Q4_05_Validate_BST;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class Question {\r\n\tpublic static Integer lastPrinted = null;\r\n\r\n\tpublic static boolean checkBST(TreeNode node) {\r\n\t\treturn checkBST(node, true);\r\n\t}\r\n\r\n\t// Allow \"equal\" value only for left child. This validates the BST property.\r\n\tpublic static boolean checkBST(TreeNode n, boolean isLeft) {\r\n\t\tif (n == null) {\r\n\t\t\treturn true;\r\n\t\t}\r\n\t\t\r\n\t\t// Check / recurse left\r\n\t\tif (!checkBST(n.left, true)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\t\r\n\t\t// Check current\r\n\t\tif (lastPrinted != null) {\r\n\t\t\tif (isLeft) {\r\n\t\t\t\t// left child \"is allowed\" be equal to parent.\r\n\t\t\t\tif (n.data < lastPrinted) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t} else {\r\n\t\t\t\t// Right child \"is not allowed\" be equal to parent.\r\n\t\t\t\tif (n.data <= lastPrinted) {\r\n\t\t\t\t\treturn false;\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t\tlastPrinted = n.data;\r\n\t\t\r\n\t\t// Check / recurse right\r\n\t\tif (!checkBST(n.right, false)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {Integer.MIN_VALUE, Integer.MAX_VALUE - 2, Integer.MAX_VALUE - 1, Integer.MAX_VALUE};\r\n\t\tTreeNode node = TreeNode.createMinimalBST(array);\r\n\t\t//node.left.data = 5;\r\n\t\t//node.left.right.data = 3;\r\n\t\tSystem.out.println(checkBST(node));\r\n\r\n\t\ttest();\r\n\t}\r\n\r\n\tpublic static void test() {\r\n\t\tTreeNode node;\r\n\t\tboolean condition;\r\n\t\tSystem.out.println(\"test cases for equals condition.\");\r\n\r\n\t\t/* Expect true: for left child: node.data <= last_printed.\r\n 2\r\n / \\\r\n / \\\r\n 2 3\r\n \\\r\n 4\r\n\t\t*/\r\n\t\tint[] array2 = {1, 2, 3, 4};\r\n\t\tnode = TreeNode.createMinimalBST(array2);\r\n\t\tnode.left.data = 2;\r\n\t\tnode.print();\r\n\t\tlastPrinted = null;\r\n\t\tcondition = checkBST(node);\r\n\t\tSystem.out.println(\"should be true: \" + condition);\r\n\r\n\t\t/* Expect false: for right child: node.data <= last_printed.\r\n 2\r\n / \\\r\n / \\\r\n 1 2\r\n \\\r\n 4\r\n\t\t */\r\n\t\tint[] array3 = {1, 2, 3, 4};\r\n\t\tnode = TreeNode.createMinimalBST(array3);\r\n\t\tnode.right.data = 2;\r\n\t\tnode.print();\r\n\t\tlastPrinted = null;\r\n\t\tcondition = checkBST(node);\r\n\t\tSystem.out.println(\"should be false: \" + condition);\r\n\t}\r\n}"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_05_Validate_BST/QuestionB.java",
"content": "package Q4_05_Validate_BST;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionB {\r\n\tpublic static boolean checkBST(TreeNode n, Integer min, Integer max) {\r\n\t\tif (n == null) {\r\n\t\t\treturn true;\r\n\t\t}\r\n\t\tif ((min != null && n.data <= min) || (max != null && n.data > max)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tif (!checkBST(n.left, min, n.data) ||\r\n\t\t\t!checkBST(n.right, n.data, max)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\t\r\n\tpublic static boolean checkBST(TreeNode n) {\r\n\t\treturn checkBST(n, null, null);\r\n\t}\r\n\t\r\n\tpublic static boolean checkBSTAlternate(TreeNode n) {\r\n\t\treturn checkBSTAlternate(n, new IntWrapper(0), new IntWrapper(0));\r\n\t}\t\t\r\n\r\n\tpublic static boolean checkBSTAlternate(TreeNode n, IntWrapper min, IntWrapper max) {\r\n\t\t/* An alternate, less clean approach. This is not provided in the book, but is used to test the other method. */\r\n\t\tif (n.left == null) {\r\n\t\t\tmin.data = n.data;\r\n\t\t} else {\r\n\t\t\tIntWrapper leftMin = new IntWrapper(0);\r\n\t\t\tIntWrapper leftMax = new IntWrapper(0);\r\n\t\t\tif (!checkBSTAlternate(n.left, leftMin, leftMax)) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tif (leftMax.data > n.data) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tmin.data = leftMin.data;\r\n\t\t}\r\n\t\tif (n.right == null) {\r\n\t\t\tmax.data = n.data;\r\n\t\t} else {\r\n\t\t\tIntWrapper rightMin = new IntWrapper(0);\r\n\t\t\tIntWrapper rightMax = new IntWrapper(0);\r\n\t\t\tif (!checkBSTAlternate(n.right, rightMin, rightMax)) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tif (rightMin.data <= n.data) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\tmax.data = rightMax.data;\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\r\n\t/* Create a tree that may or may not be a BST */\r\n\tpublic static TreeNode createTestTree() {\r\n\t\t/* Create a random BST */\r\n\t\tTreeNode head = AssortedMethods.randomBST(10, -10, 10); \r\n\t\t\r\n\t\t/* Insert an element into the BST and potentially ruin the BST property */\r\n\t\tTreeNode node = head;\r\n\t\tdo {\r\n\t\t\tint n = AssortedMethods.randomIntInRange(-10, 10);\r\n\t\t\tint rand = AssortedMethods.randomIntInRange(0, 5);\r\n\t\t\tif (rand == 0) {\r\n\t\t\t\tnode.data = n;\r\n\t\t\t} else if (rand == 1) {\r\n\t\t\t\tnode = node.left;\r\n\t\t\t} else if (rand == 2) {\r\n\t\t\t\tnode = node.right;\r\n\t\t\t} else if (rand == 3 || rand == 4) {\r\n\t\t\t\tbreak;\r\n\t\t\t}\r\n\t\t} while (node != null);\t\r\n\t\t\r\n\t\treturn head;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\t/* Simple test -- create one */\r\n\t\tint[] array = {Integer.MIN_VALUE, 3, 5, 6, 10, 13, 15, Integer.MAX_VALUE};\r\n\t\tTreeNode node = TreeNode.createMinimalBST(array);\r\n\t\t//node.left.data = 6; // \"ruin\" the BST property by changing one of the elements\r\n\t\tnode.print();\r\n\t\tboolean isBst = checkBST(node);\r\n\t\tSystem.out.println(isBst);\r\n\t\t\r\n\t\t/* More elaborate test -- creates 100 trees (some BST, some not) and compares the outputs of various methods. */\r\n\t\t/*for (int i = 0; i < 100; i++) {\r\n\t\t\tTreeNode head = createTestTree();\r\n\t\t\t\r\n\t\t\t// Compare results \r\n\t\t\tboolean isBst1 = checkBST(head);\r\n\t\t\tboolean isBst2 = checkBSTAlternate(head);\r\n\t\t\t\r\n\t\t\tif (isBst1 != isBst2) {\r\n\t\t\t\tSystem.out.println(\"*********************** ERROR *******************\");\r\n\t\t\t\thead.print();\r\n\t\t\t\tbreak;\r\n\t\t\t} else {\r\n\t\t\t\tSystem.out.println(isBst1 + \" | \" + isBst2);\r\n\t\t\t\thead.print();\r\n\t\t\t}\r\n\t\t}*/\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_06_Successor/Question.java",
"content": "package Q4_06_Successor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class Question {\r\n\r\n\tpublic static TreeNode inorderSucc(TreeNode n) { \r\n\t\tif (n == null) return null;\r\n\t\t\r\n\t\t// Found right children -> return left most node of right subtree\r\n\t\tif (n.parent == null || n.right != null) { \r\n\t\t\treturn leftMostChild(n.right); \r\n\t\t} else { \r\n\t\t\tTreeNode q = n;\r\n\t\t\tTreeNode x = q.parent;\r\n\t\t\t// Go up until we're on left instead of right\r\n\t\t\twhile (x != null && x.left != q) {\r\n\t\t\t\tq = x;\r\n\t\t\t\tx = x.parent;\r\n\t\t\t}\r\n\t\t\treturn x;\r\n\t\t} \r\n\t} \r\n\t\t\r\n\tpublic static TreeNode leftMostChild(TreeNode n) {\r\n\t\tif (n == null) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\twhile (n.left != null) {\r\n\t\t\tn = n.left; \r\n\t\t}\r\n\t\treturn n; \r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tfor (int i = 0; i < array.length; i++) {\r\n\t\t\tTreeNode node = root.find(array[i]);\r\n\t\t\tTreeNode next = inorderSucc(node);\r\n\t\t\tif (next != null) {\r\n\t\t\t\tSystem.out.println(node.data + \"->\" + next.data);\r\n\t\t\t} else {\r\n\t\t\t\tSystem.out.println(node.data + \"->\" + null);\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/DFS/Graph.java",
"content": "package Q4_07_Build_Order.DFS;\n\nimport java.util.ArrayList;\nimport java.util.HashMap;\n\npublic class Graph {\n\tprivate ArrayList nodes = new ArrayList();\n\tprivate HashMap map = new HashMap();\n\t\n\tpublic Project getOrCreateNode(String name) {\n\t\tif (!map.containsKey(name)) {\n\t\t\tProject node = new Project(name);\n\t\t\tnodes.add(node);\n\t\t\tmap.put(name, node);\n\t\t}\n\t\t\n\t\treturn map.get(name);\n\t}\n\t\n\tpublic void addEdge(String startName, String endName) {\n\t\tProject start = getOrCreateNode(startName);\n\t\tProject end = getOrCreateNode(endName);\n\t\tstart.addNeighbor(end);\n\t}\n\t\n\tpublic ArrayList getNodes() {\n\t\treturn nodes;\n\t}\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/DFS/Project.java",
"content": "package Q4_07_Build_Order.DFS;\n\nimport java.util.ArrayList;\nimport java.util.HashMap;\n\npublic class Project {\n\tpublic enum State {COMPLETE, PARTIAL, BLANK};\n\tprivate ArrayList children = new ArrayList();\n\tprivate HashMap map = new HashMap();\n\tprivate String name;\n\tprivate State state = State.BLANK;\n\t\n\tpublic Project(String n) {\n\t\tname = n;\n\t}\n\n\tpublic String getName() {\n\t\treturn name;\n\t}\n\t\n\tpublic void addNeighbor(Project node) {\n\t\tif (!map.containsKey(node.getName())) {\n\t\t\tchildren.add(node);\n\t\t\tmap.put(node.getName(), node);\n\t\t}\n\t}\n\t\n\tpublic State getState() { \n\t\treturn state;\n\t}\n\t\n\tpublic void setState(State st) {\n\t\tstate = st;\n\t}\n\t\n\tpublic ArrayList getChildren() {\n\t\treturn children;\n\t}\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/DFS/Question.java",
"content": "package Q4_07_Build_Order.DFS;\n\nimport java.util.ArrayList;\nimport java.util.Stack;\n\npublic class Question {\n\n\t/* Build the graph, adding the edge (a, b) if b is dependent on a. \n\t * Assumes a pair is listed in “build order” (which is the reverse \n\t * of dependency order). The pair (a, b) in dependencies indicates\n\t * that b depends on a and a must be built before a. */\n\tpublic static Graph buildGraph(String[] projects, String[][] dependencies) {\n\t\tGraph graph = new Graph();\n\t\t\n\t\tfor (String[] dependency : dependencies) {\n\t\t\tString first = dependency[0];\n\t\t\tString second = dependency[1];\n\t\t\tgraph.addEdge(first, second);\n\t\t}\n\t\t\n\t\treturn graph;\n\t}\n\t\n\tpublic static boolean doDFS(Project project, Stack stack) {\n\t\tif (project.getState() == Project.State.PARTIAL) {\n\t\t\treturn false; // Cycle\n\t\t}\n\t\t\n\t\tif (project.getState() == Project.State.BLANK) {\n\t\t\tproject.setState(Project.State.PARTIAL);\n\t\t\tArrayList children = project.getChildren();\n\t\t\tfor (Project child : children) {\n\t\t\t\tif (!doDFS(child, stack)) {\n\t\t\t\t\treturn false;\n\t\t\t\t}\n\t\t\t}\n\t\t\tproject.setState(Project.State.COMPLETE);\n\t\t\tstack.push(project);\n\t\t}\n\t\treturn true;\n\t}\n\t\n\tpublic static Stack orderProjects(ArrayList projects) {\n\t\tStack stack = new Stack();\n\t\tfor (Project project : projects) {\n\t\t\tif (project.getState() == Project.State.BLANK) {\n\t\t\t\tif (!doDFS(project, stack)) {\n\t\t\t\t\treturn null;\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t\treturn stack;\n\t}\n\t\n\tpublic static String[] convertToStringList(Stack projects) {\n\t\tString[] buildOrder = new String[projects.size()];\n\t\tfor (int i = 0; i < buildOrder.length; i++) {\n\t\t\tbuildOrder[i] = projects.pop().getName();\n\t\t}\n\t\treturn buildOrder;\n\t}\n\t\n\tpublic static Stack findBuildOrder(String[] projects, String[][] dependencies) {\n\t\tGraph graph = buildGraph(projects, dependencies);\n\t\treturn orderProjects(graph.getNodes());\n\t}\n\t\n\tpublic static String[] buildOrderWrapper(String[] projects, String[][] dependencies) {\n\t\tStack buildOrder = findBuildOrder(projects, dependencies);\n\t\tif (buildOrder == null) return null;\n\t\tString[] buildOrderString = convertToStringList(buildOrder);\n\t\treturn buildOrderString;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString[] projects = {\"a\", \"b\", \"c\", \"d\", \"e\", \"f\", \"g\", \"h\", \"i\", \"j\"};\n\t\tString[][] dependencies = {\n\t\t\t\t{\"a\", \"b\"},\n\t\t\t\t{\"b\", \"c\"},\n\t\t\t\t{\"a\", \"c\"},\n\t\t\t\t{\"d\", \"e\"},\n\t\t\t\t{\"b\", \"d\"},\n\t\t\t\t{\"e\", \"f\"},\n\t\t\t\t{\"a\", \"f\"},\n\t\t\t\t{\"h\", \"i\"},\n\t\t\t\t{\"h\", \"j\"},\n\t\t\t\t{\"i\", \"j\"},\n\t\t\t\t{\"g\", \"j\"}};\n\t\tString[] buildOrder = buildOrderWrapper(projects, dependencies);\n\t\tif (buildOrder == null) {\n\t\t\tSystem.out.println(\"Circular Dependency.\");\n\t\t} else {\n\t\t\tfor (String s : buildOrder) {\n\t\t\t\tSystem.out.println(s);\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/EdgeRemoval/Graph.java",
"content": "package Q4_07_Build_Order.EdgeRemoval;\n\nimport java.util.ArrayList;\nimport java.util.HashMap;\n\npublic class Graph {\n\tprivate ArrayList nodes = new ArrayList();\n\tprivate HashMap map = new HashMap();\n\t\n\tpublic Project getOrCreateNode(String name) {\n\t\tif (!map.containsKey(name)) {\n\t\t\tProject node = new Project(name);\n\t\t\tnodes.add(node);\n\t\t\tmap.put(name, node);\n\t\t}\n\t\t\n\t\treturn map.get(name);\n\t}\n\t\n\tpublic void addEdge(String startName, String endName) {\n\t\tProject start = getOrCreateNode(startName);\n\t\tProject end = getOrCreateNode(endName);\n\t\tstart.addNeighbor(end);\n\t}\n\t\n\tpublic ArrayList getNodes() {\n\t\treturn nodes;\n\t}\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/EdgeRemoval/Project.java",
"content": "package Q4_07_Build_Order.EdgeRemoval;\n\nimport java.util.ArrayList;\nimport java.util.HashMap;\n\npublic class Project {\n\tprivate ArrayList children = new ArrayList();\n\tprivate HashMap map = new HashMap();\n\tprivate String name;\n\tprivate int dependencies = 0;\n\t\n\tpublic Project(String n) {\n\t\tname = n;\n\t}\n\n\tpublic String getName() {\n\t\treturn name;\n\t}\n\t\n\tpublic void addNeighbor(Project node) {\n\t\tif (!map.containsKey(node.getName())) {\n\t\t\tchildren.add(node);\n\t\t\tmap.put(node.getName(), node);\n\t\t\tnode.incrementDependencies();\n\t\t}\n\t}\n\t\n\tpublic void incrementDependencies() {\n\t\tdependencies++;\n\t}\n\t\n\tpublic ArrayList getChildren() {\n\t\treturn children;\n\t}\n\t\n\tpublic void decrementDependencies() {\n\t\tdependencies--;\n\t}\n\t\n\tpublic int getNumberDependencies() {\n\t\treturn dependencies;\n\t}\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_07_Build_Order/EdgeRemoval/Question.java",
"content": "package Q4_07_Build_Order.EdgeRemoval;\n\nimport java.util.ArrayList;\n\npublic class Question {\n\n\t/* Build the graph, adding the edge (a, b) if b is dependent on a. \n\t * Assumes a pair is listed in “build order”. The pair (a, b) in \n\t * dependencies indicates that b depends on a and a must be built\n\t * before b. */\n\tpublic static Graph buildGraph(String[] projects, String[][] dependencies) {\n\t\tGraph graph = new Graph();\n\t\tfor (String project : projects) {\n\t\t\tgraph.getOrCreateNode(project);\n\t\t}\n\t\t\n\t\tfor (String[] dependency : dependencies) {\n\t\t\tString first = dependency[0];\n\t\t\tString second = dependency[1];\n\t\t\tgraph.addEdge(first, second);\n\t\t}\n\t\t\n\t\treturn graph;\n\t}\n\t\n\t/* A helper function to insert projects with zero dependencies \n\t * into the order array, starting at index offset. */\n\tpublic static int addNonDependent(Project[] order, ArrayList projects, int offset) {\n\t\tfor (Project project : projects) {\n\t\t\tif (project.getNumberDependencies() == 0) {\n\t\t\t\torder[offset] = project;\n\t\t\t\toffset++;\n\t\t\t}\n\t\t}\n\t\treturn offset;\n\t}\n\t\n\tpublic static Project[] orderProjects(ArrayList projects) {\n\t\tProject[] order = new Project[projects.size()];\n\t\t\n\t\t/* Add “roots” to the build order first.*/\n\t\tint endOfList = addNonDependent(order, projects, 0);\n\t\t\n\t\tint toBeProcessed = 0;\n\t\twhile (toBeProcessed < order.length) {\n\t\t\tProject current = order[toBeProcessed];\n\t\t\t\n\t\t\t/* We have a circular dependency since there are no remaining\n\t\t\t * projects with zero dependencies. */ \n\t\t\tif (current == null) {\n\t\t\t\treturn null;\n\t\t\t}\n\t\t\t\n\t\t\t/* Remove myself as a dependency. */\n\t\t\tArrayList children = current.getChildren();\n\t\t\tfor (Project child : children) {\n\t\t\t\tchild.decrementDependencies();\n\t\t\t}\t\t\t\n\t\t\t\n\t\t\t/* Add children that have no one depending on them. */\n\t\t\tendOfList = addNonDependent(order, children, endOfList);\n\t\t\t\n\t\t\ttoBeProcessed++;\n\t\t}\n\t\t\n\t\treturn order;\n\t}\n\t\n\tpublic static String[] convertToStringList(Project[] projects) {\n\t\tString[] buildOrder = new String[projects.length];\n\t\tfor (int i = 0; i < projects.length; i++) {\n\t\t\tbuildOrder[i] = projects[i].getName();\n\t\t}\n\t\treturn buildOrder;\n\t}\n\t\n\tpublic static Project[] findBuildOrder(String[] projects, String[][] dependencies) {\n\t\tGraph graph = buildGraph(projects, dependencies);\n\t\treturn orderProjects(graph.getNodes());\n\t}\n\t\n\t\n\tpublic static String[] buildOrderWrapper(String[] projects, String[][] dependencies) {\n\t\tProject[] buildOrder = findBuildOrder(projects, dependencies);\n\t\tif (buildOrder == null) return null;\n\t\tString[] buildOrderString = convertToStringList(buildOrder);\n\t\treturn buildOrderString;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tString[] projects = {\"a\", \"b\", \"c\", \"d\", \"e\", \"f\", \"g\", \"h\", \"i\", \"j\"};\n\t\tString[][] dependencies = {\n\t\t\t\t{\"a\", \"b\"},\n\t\t\t\t{\"b\", \"c\"},\n\t\t\t\t{\"a\", \"c\"},\n\t\t\t\t{\"a\", \"c\"},\n\t\t\t\t{\"d\", \"e\"},\n\t\t\t\t{\"b\", \"d\"},\n\t\t\t\t{\"e\", \"f\"},\n\t\t\t\t{\"a\", \"f\"},\n\t\t\t\t{\"h\", \"i\"},\n\t\t\t\t{\"h\", \"j\"},\n\t\t\t\t{\"i\", \"j\"},\n\t\t\t\t{\"g\", \"j\"}};\n\t\tString[] buildOrder = buildOrderWrapper(projects, dependencies);\n\t\tif (buildOrder == null) {\n\t\t\tSystem.out.println(\"Circular Dependency.\");\n\t\t} else {\n\t\t\tfor (String s : buildOrder) {\n\t\t\t\tSystem.out.println(s);\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/Question.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class Question {\r\n\tstatic int TWO_NODES_FOUND = 2;\r\n\tstatic int ONE_NODE_FOUND = 1;\r\n\tstatic int NO_NODES_FOUND = 0;\r\n\t\t\r\n\t// Checks how many 'special' nodes are located under this root\r\n\tpublic static int covers(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tint ret = NO_NODES_FOUND;\r\n\t\tif (root == null) return ret;\r\n\t\tif (root == p || root == q) ret += 1;\r\n\t\tret += covers(root.left, p, q);\r\n\t\tif(ret == TWO_NODES_FOUND) // Found p and q \r\n\t\t\treturn ret;\r\n\t\treturn ret + covers(root.right, p, q);\r\n\t}\r\n\t\t\r\n\tpublic static TreeNode commonAncestor(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (q == p && (root.left == q || root.right == q)) return root;\r\n\t\tint nodesFromLeft = covers(root.left, p, q); // Check left side\r\n\t\tif (nodesFromLeft == TWO_NODES_FOUND) {\r\n\t\t\tif(root.left == p || root.left == q) return root.left;\r\n\t\t\telse return commonAncestor(root.left, p, q);\r\n\t\t} else if (nodesFromLeft == ONE_NODE_FOUND) {\r\n\t\t\tif (root == p) return p;\r\n\t\t\telse if (root == q) return q;\r\n\t\t}\r\n\r\n\t\tint nodesFromRight = covers(root.right, p, q); // Check right side\r\n\t\tif(nodesFromRight == TWO_NODES_FOUND) {\r\n\t\t\tif(root.right == p || root.right == q) return root.right;\r\n\t\t\telse return commonAncestor(root.right, p, q);\r\n\t\t} else if (nodesFromRight == ONE_NODE_FOUND) {\r\n\t\t\tif (root == p) return p;\r\n\t\t\telse if (root == q) return q;\r\n\t\t}\r\n\t\tif (nodesFromLeft == ONE_NODE_FOUND && \r\n\t\t\tnodesFromRight == ONE_NODE_FOUND) return root;\r\n\t\telse return null;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(1);\r\n\t\tTreeNode n7 = root.find(7);\r\n\t\tTreeNode ancestor = commonAncestor(root, n3, n7);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionA.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionA {\r\n\tpublic static TreeNode commonAncestor(TreeNode p, TreeNode q) {\r\n\t\tif (p == q) return p;\r\n\t\t\r\n\t\tTreeNode ancestor = p;\r\n\t\twhile (ancestor != null) {\r\n\t\t\tif (isOnPath(ancestor, q)) {\r\n\t\t\t\treturn ancestor;\r\n\t\t\t}\r\n\t\t\tancestor = ancestor.parent;\r\n\t\t}\r\n\t\treturn null;\r\n\t}\r\n\t\r\n\tpublic static boolean isOnPath(TreeNode ancestor, TreeNode node) {\r\n\t\twhile (node != ancestor && node != null) {\r\n\t\t\tnode = node.parent;\r\n\t\t}\r\n\t\treturn node == ancestor;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(8);\r\n\t\tTreeNode n7 = root.find(8);\r\n\t\tTreeNode ancestor = commonAncestor(n3, n7);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionB.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionB {\r\n\tpublic static TreeNode commonAncestor(TreeNode p, TreeNode q) {\r\n\t\tint delta = depth(p) - depth(q); // get difference in depths\r\n\t\tTreeNode first = delta > 0 ? q : p; // get shallower node\r\n\t\tTreeNode second = delta > 0 ? p : q; // get deeper node\r\n\t\tsecond = goUpBy(second, Math.abs(delta)); // move shallower node to depth of deeper\r\n\t\twhile (first != second && first != null && second != null) {\r\n\t\t\tfirst = first.parent;\r\n\t\t\tsecond = second.parent;\r\n\t\t}\r\n\t\treturn first == null || second == null ? null : first;\r\n\t}\r\n\t\r\n\tpublic static TreeNode goUpBy(TreeNode node, int delta) {\r\n\t\twhile (delta > 0 && node != null) {\r\n\t\t\tnode = node.parent;\r\n\t\t\tdelta--;\r\n\t\t}\r\n\t\treturn node;\r\n\t}\r\n\t\r\n\tpublic static int depth(TreeNode node) {\r\n\t\tint depth = 0;\r\n\t\twhile (node != null) {\r\n\t\t\tnode = node.parent;\r\n\t\t\tdepth++;\r\n\t\t}\r\n\t\treturn depth;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(3);\r\n\t\tTreeNode n7 = root.find(7);\r\n\t\tTreeNode ancestor = commonAncestor(n3, n7);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionC.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionC {\r\n\t\r\n\tpublic static TreeNode commonAncestor(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (!covers(root, p) || !covers(root, q)) {\r\n\t\t\treturn null;\r\n\t\t} else if (covers(p, q)) {\r\n\t\t\treturn p;\r\n\t\t} else if (covers(q, p)) {\r\n\t\t\treturn q;\r\n\t\t}\r\n\t\t\r\n\t\tTreeNode sibling = getSibling(p);\r\n\t\tTreeNode parent = p.parent;\r\n\t\twhile (!covers(sibling, q)) {\r\n\t\t\tsibling = getSibling(parent);\r\n\t\t\tparent = parent.parent;\r\n\t\t}\r\n\t\treturn parent;\r\n\t}\r\n\t\r\n\tpublic static boolean covers(TreeNode root, TreeNode p) { \r\n\t\tif (root == null) return false;\r\n\t\tif (root == p) return true;\r\n\t\treturn covers(root.left, p) || covers(root.right, p); \r\n\t}\r\n\t\r\n\tpublic static TreeNode getSibling(TreeNode node) {\r\n\t\tif (node == null || node.parent == null) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\t\r\n\t\tTreeNode parent = node.parent;\r\n\t\treturn parent.left == node ? parent.right : parent.left;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(1);\r\n\t\tTreeNode n7 = root.find(7);\r\n\t\tTreeNode ancestor = commonAncestor(root, n3, n7);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionD.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionD {\r\n\t\r\n\tpublic static TreeNode commonAncestor(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (!covers(root, p) || !covers(root, q)) { // Error check - one node is not in tree\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\treturn ancestorHelper(root, p, q);\r\n\t}\r\n\t\r\n\tpublic static TreeNode ancestorHelper(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (root == null || root == p || root == q) {\r\n\t\t\treturn root;\r\n\t\t}\r\n\t\t\r\n\t\tboolean pIsOnLeft = covers(root.left, p);\r\n\t\tboolean qIsOnLeft = covers(root.left, q);\r\n\t\tif (pIsOnLeft != qIsOnLeft) { // Nodes are on different side\r\n\t\t\treturn root;\r\n\t\t}\r\n\t\tTreeNode childSide = pIsOnLeft ? root.left : root.right;\r\n\t\treturn ancestorHelper(childSide, p, q);\r\n\t}\t\r\n\t\r\n\tpublic static boolean covers(TreeNode root, TreeNode p) { \r\n\t\tif (root == null) return false;\r\n\t\tif (root == p) return true;\r\n\t\treturn covers(root.left, p) || covers(root.right, p); \r\n\t}\r\n\t\t\r\n\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(1);\r\n\t\tTreeNode n7 = root.find(7);\r\n\t\tTreeNode ancestor = commonAncestor(root, n3, n7);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionE.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionE {\r\n\tpublic static class Result {\r\n\t\tpublic TreeNode node;\r\n\t\tpublic boolean isAncestor;\r\n\t\tpublic Result(TreeNode n, boolean isAnc) {\r\n\t\t\tnode = n;\r\n\t\t\tisAncestor = isAnc;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static Result commonAncestorHelper(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (root == null) {\r\n\t\t\treturn new Result(null, false);\r\n\t\t}\r\n\t\tif (root == p && root == q) {\r\n\t\t\treturn new Result(root, true);\r\n\t\t}\r\n\t\t\r\n\t\tResult rx = commonAncestorHelper(root.left, p, q);\r\n\t\tif (rx.isAncestor) { // Found common ancestor\r\n\t\t\treturn rx;\r\n\t\t}\r\n\t\t\r\n\t\tResult ry = commonAncestorHelper(root.right, p, q);\r\n\t\tif (ry.isAncestor) { // Found common ancestor\r\n\t\t\treturn ry;\r\n\t\t}\r\n\t\t\r\n\t\tif (rx.node != null && ry.node != null) {\r\n\t\t\treturn new Result(root, true); // This is the common ancestor\r\n\t\t} else if (root == p || root == q) {\r\n\t\t\t/* If we�re currently at p or q, and we also found one of those\r\n\t\t\t * nodes in a subtree, then this is truly an ancestor and the\r\n\t\t\t * flag should be true. */\r\n\t\t\tboolean isAncestor = rx.node != null || ry.node != null;\r\n\t\t\treturn new Result(root, isAncestor);\r\n\t\t} else {\r\n\t\t\treturn new Result(rx.node != null ? rx.node : ry.node, false);\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tpublic static TreeNode commonAncestor(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tResult r = commonAncestorHelper(root, p, q);\r\n\t\tif (r.isAncestor) {\r\n\t\t\treturn r.node;\r\n\t\t}\r\n\t\treturn null;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(10);\r\n\t\tTreeNode n7 = root.find(6);\r\n\t\tTreeNode ancestor = commonAncestor(root, n3, n7);\r\n\t\tif (ancestor != null) {\r\n\t\t\tSystem.out.println(ancestor.data);\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"null\");\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionEBad.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionEBad {\r\n\tpublic static TreeNode commonAncestorBad(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif (root == null) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\tif (root == p && root == q) {\r\n\t\t\treturn root;\r\n\t\t}\r\n\t\t\r\n\t\tTreeNode x = commonAncestorBad(root.left, p, q);\r\n\t\tif (x != null && x != p && x != q) { // Found common ancestor\r\n\t\t\treturn x;\r\n\t\t}\r\n\t\t\r\n\t\tTreeNode y = commonAncestorBad(root.right, p, q);\r\n\t\tif (y != null && y != p && y != q) {\r\n\t\t\treturn y;\r\n\t\t}\r\n\t\t\r\n\t\tif (x != null && y != null) {\r\n\t\t\treturn root; // This is the common ancestor\r\n\t\t} else if (root == p || root == q) {\r\n\t\t\treturn root;\r\n\t\t} else {\r\n\t\t\treturn x == null ? y : x;\r\n\t\t}\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\r\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\r\n\t\tTreeNode n3 = root.find(9);\r\n\t\tTreeNode n7 = new TreeNode(6);//root.find(10);\r\n\t\tTreeNode ancestor = commonAncestorBad(root, n3, n7);\r\n\t\tif (ancestor != null) {\r\n\t\t\tSystem.out.println(ancestor.data);\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"null\");\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/QuestionF.java",
"content": "package Q4_08_First_Common_Ancestor;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionF {\r\n\t\r\n\tpublic static TreeNode commonAncestor(TreeNode root, TreeNode p, TreeNode q) {\r\n\t\tif ((p == null) || (q == null)) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\t\r\n\t\tTreeNode ap = p.parent;\r\n\t\twhile (ap != null) {\r\n\t\t\tTreeNode aq = q.parent;\r\n\t\t\twhile (aq != null) { \r\n\t\t\t\tif (aq == ap) {\r\n\t\t\t\t\treturn aq;\r\n\t\t\t\t}\r\n\t\t\t\taq = aq.parent;\r\n\t\t\t}\r\n\t\t\tap = ap.parent;\r\n\t\t}\r\n\t\treturn null;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint[] array = {5, 3, 6, 1, 9, 11};\r\n\t\tTreeNode root = new TreeNode(20);\r\n\t\tfor (int a : array) {\r\n\t\t\troot.insertInOrder(a);\r\n\t\t}\r\n\t\tTreeNode n1 = root.find(1);\r\n\t\tTreeNode n9 = root.find(9);\r\n\t\tTreeNode ancestor = commonAncestor(root, n1, n9);\r\n\t\tSystem.out.println(ancestor.data);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_08_First_Common_Ancestor/Tester.java",
"content": "package Q4_08_First_Common_Ancestor;\n\nimport java.util.ArrayList;\n\nimport CtCILibrary.TreeNode;\n\npublic class Tester {\n\tpublic static String resultToString(String s, TreeNode x, TreeNode y, TreeNode anc) {\n\t\ts += \": \";\n\t\ts += (x == null ? \"null\" : x.data);\n\t\ts += \" & \";\n\t\ts += (y == null ? \"null\" : y.data);\n\t\ts += \" -> \";\n\t\ts += (anc == null ? \"null\" : anc.data);\n\t\treturn s;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};\n\t\tTreeNode root = TreeNode.createMinimalBST(array);\n\t\t\n\t\tArrayList nodes = new ArrayList();\n\t\tfor (int a : array) {\n\t\t\tnodes.add(root.find(a));\n\t\t}\n\t\tnodes.add(new TreeNode(11));\n\t\t\n\t\tfor (TreeNode x : nodes) {\n\t\t\tfor (TreeNode y : nodes) {\n\t\t\t\tTreeNode r1 = QuestionA.commonAncestor(x, y);\n\t\t\t\tTreeNode r2 = QuestionB.commonAncestor(x, y);\n\t\t\t\tTreeNode r3 = QuestionC.commonAncestor(root, x, y);\n\t\t\t\tTreeNode r4 = QuestionD.commonAncestor(root, x, y);\n\t\t\t\tTreeNode r5 = QuestionE.commonAncestor(root, x, y);\n\t\t\t\t\n\t\t\t\tString s1 = resultToString(\"A\", x, y, r1);\n\t\t\t\tString s2 = resultToString(\"B\", x, y, r2);\n\t\t\t\tString s3 = resultToString(\"C\", x, y, r3);\n\t\t\t\tString s4 = resultToString(\"D\", x, y, r4);\n\t\t\t\tString s5 = resultToString(\"D\", x, y, r5);\n\t\t\t\t\n\t\t\t\tif (r1 == r2 && r2 == r3 && r3 == r4 && r4 == r5) {\n\t\t\t\t\tSystem.out.println(\"SUCCESS: \" + s1);\n\t\t\t\t} else {\n\t\t\t\t\tSystem.out.println(\"ERROR\");\n\t\t\t\t\tSystem.out.println(s1);\n\t\t\t\t\tSystem.out.println(s2);\n\t\t\t\t\tSystem.out.println(s3);\n\t\t\t\t\tSystem.out.println(s4);\n\t\t\t\t\tSystem.out.println(s5);\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_09_BST_Sequences/Question.java",
"content": "package Q4_09_BST_Sequences;\n\nimport java.util.ArrayList;\nimport java.util.LinkedList;\n\nimport CtCILibrary.TreeNode;\n\npublic class Question {\n\t\n\tpublic static void weaveLists(LinkedList first, LinkedList second, ArrayList> results, LinkedList prefix) {\n\t\t/* One list is empty. Add the remainder to [a cloned] prefix and\n\t\t * store result. */\n\t\tif (first.size() == 0 || second.size() == 0) {\n\t\t\tLinkedList result = (LinkedList) prefix.clone();\n\t\t\tresult.addAll(first);\n\t\t\tresult.addAll(second);\n\t\t\tresults.add(result);\n\t\t\treturn;\n\t\t}\n\t\t\n\t\t/* Recurse with head of first added to the prefix. Removing the\n\t\t * head will damage first, so we’ll need to put it back where we\n\t\t * found it afterwards. */\n\t\tint headFirst = first.removeFirst();\n\t\tprefix.addLast(headFirst);\n\t\tweaveLists(first, second, results, prefix);\n\t\tprefix.removeLast();\n\t\tfirst.addFirst(headFirst);\n\t\t\n\t\t/* Do the same thing with second, damaging and then restoring\n\t\t * the list.*/\n\t\tint headSecond = second.removeFirst();\n\t\tprefix.addLast(headSecond);\n\t\tweaveLists(first, second, results, prefix);\n\t\tprefix.removeLast();\t\n\t\tsecond.addFirst(headSecond);\n\t}\n\t\n\tpublic static ArrayList> allSequences(TreeNode node) {\n\t\tArrayList> result = new ArrayList>();\n\t\t\n\t\tif (node == null) {\n\t\t\tresult.add(new LinkedList());\n\t\t\treturn result;\n\t\t} \n\t\t\n\t\tLinkedList prefix = new LinkedList();\n\t\tprefix.add(node.data);\n\t\t\n\t\t/* Recurse on left and right subtrees. */\n\t\tArrayList> leftSeq = allSequences(node.left);\n\t\tArrayList> rightSeq = allSequences(node.right);\n\t\t\n\t\t/* Weave together each list from the left and right sides. */\n\t\tfor (LinkedList left : leftSeq) {\n\t\t\tfor (LinkedList right : rightSeq) {\n\t\t\t\tArrayList> weaved = new ArrayList>();\n\t\t\t\tweaveLists(left, right, weaved, prefix);\n\t\t\t\tresult.addAll(weaved);\n\t\t\t}\n\t\t}\n\t\treturn result;\n\t}\n\n\tpublic static void main(String[] args) {\n\t\tTreeNode node = new TreeNode(100);\n\t\tint[] array = {100, 50, 20, 75, 150, 120, 170};\n\t\tfor (int a : array) {\n\t\t\tnode.insertInOrder(a);\n\t\t}\n\t\tArrayList> allSeq = allSequences(node);\n\t\tfor (LinkedList list : allSeq) {\n\t\t\tSystem.out.println(list);\n\t\t}\n\t\tSystem.out.println(allSeq.size());\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_10_Check_Subtree/QuestionA.java",
"content": "package Q4_10_Check_Subtree;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionA {\r\n\t\r\n\tpublic static boolean containsTree(TreeNode t1, TreeNode t2) {\r\n\t\tStringBuilder string1 = new StringBuilder();\r\n\t\tStringBuilder string2 = new StringBuilder();\r\n\t\t\r\n\t\tgetOrderString(t1, string1);\r\n\t\tgetOrderString(t2, string2);\r\n\t\t\r\n\t\treturn string1.indexOf(string2.toString()) != -1;\r\n\t}\r\n\t\r\n\tpublic static void getOrderString(TreeNode node, StringBuilder sb) {\r\n\t\tif (node == null) {\r\n\t\t\tsb.append(\"X\"); // Add null indicator\r\n\t\t\treturn;\r\n\t\t}\r\n\t\tsb.append(node.data); // Add root \r\n\t\tgetOrderString(node.left, sb); // Add left\r\n\t\tgetOrderString(node.right, sb); // Add right\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\t// t2 is a subtree of t1\r\n\t\tint[] array1 = {1, 2, 1, 3, 1, 1, 5};\r\n\t\tint[] array2 = {2, 3, 1};\r\n\t\t\r\n\t\tTreeNode t1 = AssortedMethods.createTreeFromArray(array1);\r\n\t\tTreeNode t2 = AssortedMethods.createTreeFromArray(array2);\r\n\r\n\t\tif (containsTree(t1, t2)) {\r\n\t\t\tSystem.out.println(\"t2 is a subtree of t1\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"t2 is not a subtree of t1\");\r\n\t\t}\r\n\r\n\t\t// t4 is not a subtree of t3\r\n\t\tint[] array3 = {1, 2, 3};\r\n\t\tTreeNode t3 = AssortedMethods.createTreeFromArray(array1);\r\n\t\tTreeNode t4 = AssortedMethods.createTreeFromArray(array3);\r\n\r\n\t\tif (containsTree(t3, t4)) {\r\n\t\t\tSystem.out.println(\"t4 is a subtree of t3\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"t4 is not a subtree of t3\");\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_10_Check_Subtree/QuestionB.java",
"content": "package Q4_10_Check_Subtree;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionB {\r\n\r\n\tpublic static boolean containsTree(TreeNode t1, TreeNode t2) {\r\n\t\tif (t2 == null) {\r\n\t\t\treturn true; // The empty tree is a subtree of every tree.\r\n\t\t}\r\n\t\treturn subTree(t1, t2);\r\n\t}\r\n\t\r\n\t/* Checks if the binary tree rooted at r1 contains the binary tree \r\n\t * rooted at r2 as a subtree somewhere within it.\r\n\t */\r\n\tpublic static boolean subTree(TreeNode r1, TreeNode r2) {\r\n\t\tif (r1 == null) {\r\n\t\t\treturn false; // big tree empty & subtree still not found.\r\n\t\t} else if (r1.data == r2.data && matchTree(r1,r2)) {\r\n\t\t\treturn true;\r\n\t\t}\r\n\t\treturn subTree(r1.left, r2) || subTree(r1.right, r2); \r\n\t}\r\n\r\n\t/* Checks if the binary tree rooted at r1 contains the \r\n\t * binary tree rooted at r2 as a subtree starting at r1.\r\n\t */\r\n\tpublic static boolean matchTree(TreeNode r1, TreeNode r2) {\r\n\t\tif (r1 == null && r2 == null) {\r\n\t\t\treturn true; // nothing left in the subtree\r\n\t\t} else if (r1 == null || r2 == null) { \r\n\t\t\treturn false; // exactly one tree is empty, therefore trees don't match\r\n\t\t} else if (r1.data != r2.data) { \r\n\t\t\treturn false; // data doesn't match\r\n\t\t} else {\r\n\t\t\treturn matchTree(r1.left, r2.left) && matchTree(r1.right, r2.right);\r\n\t\t}\r\n\t}\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\t// t2 is a subtree of t1\r\n\t\tint[] array1 = {1, 2, 1, 3, 1, 1, 5};\r\n\t\tint[] array2 = {2, 3, 1};\r\n\t\t\r\n\t\tTreeNode t1 = AssortedMethods.createTreeFromArray(array1);\r\n\t\tTreeNode t2 = AssortedMethods.createTreeFromArray(array2);\r\n\r\n\t\tif (containsTree(t1, t2)) {\r\n\t\t\tSystem.out.println(\"t2 is a subtree of t1\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"t2 is not a subtree of t1\");\r\n\t\t}\r\n\r\n\t\t// t4 is not a subtree of t3\r\n\t\tint[] array3 = {1, 2, 3};\r\n\t\tTreeNode t3 = AssortedMethods.createTreeFromArray(array1);\r\n\t\tTreeNode t4 = AssortedMethods.createTreeFromArray(array3);\r\n\r\n\t\tif (containsTree(t3, t4)) {\r\n\t\t\tSystem.out.println(\"t4 is a subtree of t3\");\r\n\t\t} else {\r\n\t\t\tSystem.out.println(\"t4 is not a subtree of t3\");\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_11_Random_Node/Question.java",
"content": "package Q4_11_Random_Node;\n\npublic class Question {\n\n\tpublic static void main(String[] args) {\n\t\tint[] counts = new int[10];\n\t\tfor (int i = 0; i < 1000000; i++) {\n\t\t\tTree tree = new Tree();\n\t\t\tint[] array = {1, 0, 6, 2, 3, 9, 4, 5, 8, 7};\n\t\t\tfor (int x : array) {\n\t\t\t\ttree.insertInOrder(x);\n\t\t\t}\n\t\t\tint d = tree.getRandomNode().data;\n\t\t\tcounts[d]++;\n\t\t}\n\t\t\n\t\tfor (int i = 0; i < counts.length; i++) {\n\t\t\tSystem.out.println(i + \": \" + counts[i]);\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_11_Random_Node/Tree.java",
"content": "package Q4_11_Random_Node;\n\nimport java.util.Random;\n\npublic class Tree {\n\tTreeNode root = null;\n\t\n\tpublic void insertInOrder(int value) {\n\t\tif (root == null) {\n\t\t\troot = new TreeNode(value);\n\t\t} else {\n\t\t\troot.insertInOrder(value);\n\t\t}\n\t}\n\t\n\tpublic int size() {\n\t\treturn root == null ? 0 : root.size();\n\t}\n\t\n\tpublic TreeNode getRandomNode() {\n\t\tif (root == null) return null;\n\t\t\n\t\tRandom random = new Random();\n\t\tint i = random.nextInt(size());\n\t\treturn root.getIthNode(i);\n\t}\n}\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_11_Random_Node/TreeNode.java",
"content": "package Q4_11_Random_Node;\r\n\r\nimport java.util.Random;\r\n\r\n/* One node of a binary tree. The data element stored is a single \r\n * character.\r\n */\r\npublic class TreeNode {\r\n\tpublic int data; \r\n\tpublic TreeNode left; \r\n\tpublic TreeNode right; \r\n\tprivate int size = 0;\r\n\r\n\tpublic TreeNode(int d) {\r\n\t\tdata = d;\r\n\t\tsize = 1;\r\n\t}\r\n\t\r\n\tpublic void insertInOrder(int d) {\r\n\t\tif (d <= data) {\r\n\t\t\tif (left == null) {\r\n\t\t\t\tleft = new TreeNode(d);\r\n\t\t\t} else {\r\n\t\t\t\tleft.insertInOrder(d);\r\n\t\t\t}\r\n\t\t} else {\r\n\t\t\tif (right == null) {\r\n\t\t\t\tright = new TreeNode(d);\r\n\t\t\t} else {\r\n\t\t\t\tright.insertInOrder(d);\r\n\t\t\t}\r\n\t\t}\r\n\t\tsize++;\r\n\t}\r\n\t\r\n\tpublic int size() {\r\n\t\treturn size;\r\n\t}\r\n\t\r\n\tpublic TreeNode find(int d) {\r\n\t\tif (d == data) {\r\n\t\t\treturn this;\r\n\t\t} else if (d <= data) {\r\n\t\t\treturn left != null ? left.find(d) : null;\r\n\t\t} else if (d > data) {\r\n\t\t\treturn right != null ? right.find(d) : null;\r\n\t\t}\r\n\t\treturn null;\r\n\t}\r\n\t\r\n\tpublic TreeNode getRandomNode() {\r\n\t\tint leftSize = left == null ? 0 : left.size();\r\n\t\tRandom random = new Random();\r\n\t\tint index = random.nextInt(size);\r\n\t\tif (index < leftSize) {\r\n\t\t\treturn left.getRandomNode();\r\n\t\t} else if (index == leftSize) {\r\n\t\t\treturn this;\r\n\t\t} else {\r\n\t\t\treturn right.getRandomNode();\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic TreeNode getIthNode(int i) {\r\n\t\tint leftSize = left == null ? 0 : left.size();\r\n\t\tif (i < leftSize) {\r\n\t\t\treturn left.getIthNode(i);\r\n\t\t} else if (i == leftSize) {\r\n\t\t\treturn this;\r\n\t\t} else {\r\n\t\t\treturn right.getIthNode(i - (leftSize + 1));\r\n\t\t}\r\n\t}\r\n} \r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_12_Paths_with_Sum/QuestionA.java",
"content": "package Q4_12_Paths_with_Sum;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionA {\r\n\t\r\n\tpublic static int countPathsWithSum(TreeNode root, int targetSum) {\r\n\t\tif (root == null) return 0;\r\n\t\t\r\n\t\t/* Count paths with sum starting from the root. */\r\n\t\tint pathsFromRoot = countPathsWithSumFromNode(root, targetSum, 0);\r\n\t\t\r\n\t\t/* Try the nodes on the left and right. */\r\n\t\tint pathsOnLeft = countPathsWithSum(root.left, targetSum);\r\n\t\tint pathsOnRight = countPathsWithSum(root.right, targetSum);\r\n\t\t\r\n\t\treturn pathsFromRoot + pathsOnLeft + pathsOnRight;\r\n\t}\r\n\t\r\n\t/* Returns the number of paths with this sum starting from this node. */\r\n\tpublic static int countPathsWithSumFromNode(TreeNode node, int targetSum, int currentSum) {\r\n\t\tif (node == null) return 0;\r\n\t\r\n\t\tcurrentSum += node.data;\r\n\t\t\r\n\t\tint totalPaths = 0;\r\n\t\tif (currentSum == targetSum) { // Found a path from the root\r\n\t\t\ttotalPaths++;\r\n\t\t}\r\n\t\t\r\n\t\ttotalPaths += countPathsWithSumFromNode(node.left, targetSum, currentSum); // Go left\r\n\t\ttotalPaths += countPathsWithSumFromNode(node.right, targetSum, currentSum); // Go right\r\n\t\t\r\n\t\treturn totalPaths;\r\n\t}\t\r\n\r\n\tpublic static void main(String [] args) {\r\n\t\t/*\r\n\t\tTreeNode root = new TreeNode(5);\r\n\t\troot.left = new TreeNode(3);\t\t\r\n\t\troot.right = new TreeNode(1);\r\n\t\troot.left.left = new TreeNode(-8);\r\n\t\troot.left.right = new TreeNode(8);\r\n\t\troot.right.left = new TreeNode(2);\r\n\t\troot.right.right = new TreeNode(6);\t\r\n\t\tSystem.out.println(countPathsWithSum(root, 0));*/\r\n\t\t\r\n\t\t/*TreeNode root = new TreeNode(-7);\r\n\t\troot.left = new TreeNode(-7);\r\n\t\troot.left.right = new TreeNode(1);\r\n\t\troot.left.right.left = new TreeNode(2);\r\n\t\troot.right = new TreeNode(7);\r\n\t\troot.right.left = new TreeNode(3);\r\n\t\troot.right.right = new TreeNode(20);\r\n\t\troot.right.right.left = new TreeNode(0);\r\n\t\troot.right.right.left.left = new TreeNode(-3);\r\n\t\troot.right.right.left.left.right = new TreeNode(2);\r\n\t\troot.right.right.left.left.right.left = new TreeNode(1);\r\n\t\tSystem.out.println(countPathsWithSum(root, -14));*/\r\n\t\t\r\n\t\tTreeNode root = new TreeNode(0);\r\n\t\troot.left = new TreeNode(0);\r\n\t\troot.right = new TreeNode(0);\r\n\t\troot.right.left = new TreeNode(0);\r\n\t\troot.right.left.right = new TreeNode(0);\r\n\t\troot.right.right = new TreeNode(0);\r\n\t\tSystem.out.println(countPathsWithSum(root, 0));\r\n\t\tSystem.out.println(countPathsWithSum(root, 4));\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_12_Paths_with_Sum/QuestionB.java",
"content": "package Q4_12_Paths_with_Sum;\r\nimport java.util.HashMap;\r\n\r\nimport CtCILibrary.TreeNode;\r\n\r\npublic class QuestionB {\r\n\t\r\n\tpublic static int countPathsWithSum(TreeNode root, int targetSum) {\r\n\t\treturn countPathsWithSum(root, targetSum, 0, new HashMap());\r\n\t}\r\n\t\r\n\tpublic static int countPathsWithSum(TreeNode node, int targetSum, int runningSum, HashMap pathCount) {\r\n\t\tif (node == null) return 0; // Base case\r\n\t\t\r\n\t\trunningSum += node.data;\r\n\t\t\r\n\t\t/* Count paths with sum ending at the current node. */\r\n\t\tint sum = runningSum - targetSum;\r\n\t\tint totalPaths = pathCount.getOrDefault(sum, 0);\r\n\t\t\r\n\t\t/* If runningSum equals targetSum, then one additional path starts at root. Add in this path.*/\r\n\t\tif (runningSum == targetSum) {\r\n\t\t\ttotalPaths++;\r\n\t\t}\r\n\r\n\t\t/* Add runningSum to pathCounts. */\r\n\t\tincrementHashTable(pathCount, runningSum, 1);\r\n\t\t\r\n\t\t/* Count paths with sum on the left and right. */\r\n\t\ttotalPaths += countPathsWithSum(node.left, targetSum, runningSum, pathCount);\r\n\t\ttotalPaths += countPathsWithSum(node.right, targetSum, runningSum, pathCount);\r\n\t\t\r\n\t\tincrementHashTable(pathCount, runningSum, -1); // Remove runningSum\r\n\t\treturn totalPaths;\r\n\t}\r\n\t\r\n\tpublic static void incrementHashTable(HashMap hashTable, int key, int delta) {\r\n\t\tint newCount = hashTable.getOrDefault(key, 0) + delta;\r\n\t\tif (newCount == 0) { // Remove when zero to reduce space usage\r\n\t\t\thashTable.remove(key);\r\n\t\t} else {\r\n\t\t\thashTable.put(key, newCount);\r\n\t\t}\r\n\t}\r\n\r\n\tpublic static void main(String [] args) {\r\n\t\t/*\r\n\t\tTreeNode root = new TreeNode(5);\r\n\t\troot.left = new TreeNode(3);\t\t\r\n\t\troot.right = new TreeNode(1);\r\n\t\troot.left.left = new TreeNode(-8);\r\n\t\troot.left.right = new TreeNode(8);\r\n\t\troot.right.left = new TreeNode(2);\r\n\t\troot.right.right = new TreeNode(6);\t\r\n\t\troot.right.left.left = new TreeNode(0);\t\r\n\t\tSystem.out.println(countPathsWithSum(root, 0));\r\n\t\t*/\r\n\t\t\r\n\t\t/*TreeNode root = new TreeNode(-7);\r\n\t\troot.left = new TreeNode(-7);\r\n\t\troot.left.right = new TreeNode(1);\r\n\t\troot.left.right.left = new TreeNode(2);\r\n\t\troot.right = new TreeNode(7);\r\n\t\troot.right.left = new TreeNode(3);\r\n\t\troot.right.right = new TreeNode(20);\r\n\t\troot.right.right.left = new TreeNode(0);\r\n\t\troot.right.right.left.left = new TreeNode(-3);\r\n\t\troot.right.right.left.left.right = new TreeNode(2);\r\n\t\troot.right.right.left.left.right.left = new TreeNode(1);\r\n\t\tSystem.out.println(countPathsWithSum(root, 0));*/\r\n\t\t\r\n\t\tTreeNode root = new TreeNode(0);\r\n\t\troot.left = new TreeNode(0);\r\n\t\troot.right = new TreeNode(0);\r\n\t\troot.right.left = new TreeNode(0);\r\n\t\troot.right.left.right = new TreeNode(0);\r\n\t\troot.right.right = new TreeNode(0);\r\n\t\tSystem.out.println(countPathsWithSum(root, 0));\r\n\t\tSystem.out.println(countPathsWithSum(root, 4));\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 04. Trees and Graphs/Q4_12_Paths_with_Sum/Tester.java",
"content": "package Q4_12_Paths_with_Sum;\n\nimport CtCILibrary.AssortedMethods;\nimport CtCILibrary.TreeNode;\n\npublic class Tester {\n\n\tpublic static void main(String[] args) {\n\t\tboolean isWorking = true;\n\t\twhile (isWorking) {\n\t\t\tint min = -20;\n\t\t\tint max = 20;\n\t\t\tint size = 20;\n\t\t\tTreeNode root = AssortedMethods.randomBST(size, min, max);\n\t\t\n\t\t\tfor (int targetSum = Math.min(-1, min * size - 10); targetSum <= Math.max(100, max * size + 10); targetSum++) {\n\t\t\t\tint answerA = QuestionA.countPathsWithSum(root, targetSum);\n\t\t\t\tint answerB = QuestionB.countPathsWithSum(root, targetSum);\n\t\t\t\tif (answerA > 0 || answerB > 0) {\n\t\t\t\t\tSystem.out.println(targetSum + \": \" + answerA + \", \" + answerB + \" | \" + (answerA == answerB));\n\t\t\t\t}\n\t\t\t\tif (answerA != answerB) {\n\t\t\t\t\tisWorking = false;\n\t\t\t\t\tbreak;\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_01_Insertion/Question.java",
"content": "package Q5_01_Insertion;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\r\n\tpublic static int updateBits(int n, int m, int i, int j) {\r\n\t\t// Validation\r\n\t\tif (i > j || i < 0 || j >= 32) {\r\n\t\t\treturn 0;\r\n\t\t}\r\n\t\t\r\n\t\t/* Create a mask to clear bits i through j in n\r\n\t\t/* EXAMPLE: i = 2, j = 4. Result should be 11100011.\r\n\t\t * (Using 8 bits for this example. This is obviously not actually 8 bits.)\r\n\t\t */\r\n\t\tint allOnes = ~0; // allOnes = 11111111\r\n\t\t\r\n\t\tint left = j < 31 ? (allOnes << (j + 1)) : 0; // 1s until position j, then 0s. left = 11100000\t\r\n\t \tint right = ((1 << i) - 1); // 1s after position i. right = 00000011\r\n\t\tint mask = left | right; // All 1s, except for 0s between i and j. mask = 11100011\r\n\r\n\t\t/* Clear i through j, then put m in there */\r\n\t\tint n_cleared = n & mask; // Clear bits j through i.\r\n\t\tint m_shifted = m << i; // Move m into correct position.\r\n\t\t\r\n\t\t/* OR them, and we're done! */\r\n\t\treturn n_cleared | m_shifted; \r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint a = ~23423;\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(a));\r\n\t\tint b = 5;\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(b));\t\t\r\n\t\tint c = updateBits(a, b, 29, 31);\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(c));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_02_Binary_to_String/Question.java",
"content": "package Q5_02_Binary_to_String;\r\n\r\npublic class Question {\r\n\tpublic static String printBinary(double num) {\r\n\t\tif (num >= 1 || num <= 0) {\r\n\t\t\treturn \"ERROR\";\r\n\t\t}\r\n\t\r\n\t\tStringBuilder binary = new StringBuilder();\r\n\t\tbinary.append(\".\");\r\n\t\twhile (num > 0) {\r\n\t\t\t/* Setting a limit on length: 32 characters */\r\n\t\t\tif (binary.length() > 32) {\r\n\t\t\t\treturn \"ERROR\";\r\n\t\t\t}\r\n\t\t\tdouble r = num * 2;\r\n\t\t\tif (r >= 1) {\r\n\t\t\t\tbinary.append(1);\r\n\t\t\t\tnum = r - 1;\r\n\t\t\t} else {\r\n\t\t\t\tbinary.append(0);\r\n\t\t\t\tnum = r;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn binary.toString();\r\n\t}\r\n\t\r\n\tpublic static String printBinary2(double num) {\r\n\t\tif (num >= 1 || num <= 0) {\r\n\t\t\treturn \"ERROR\";\r\n\t\t}\r\n\t\r\n\t\tStringBuilder binary = new StringBuilder();\r\n\t\tdouble frac = 0.5;\r\n\t\tbinary.append(\".\");\r\n\t\twhile (num > 0) {\r\n\t\t\t/* Setting a limit on length: 32 characters */\r\n\t\t\tif (binary.length() >= 32) {\r\n\t\t\t\treturn \"ERROR\";\r\n\t\t\t}\r\n\t\t\tif (num >= frac) {\r\n\t\t\t\tbinary.append(1);\r\n\t\t\t\tnum -= frac;\r\n\t\t\t} else {\r\n\t\t\t\tbinary.append(0);\r\n\t\t\t}\r\n\t\t\tfrac /= 2;\r\n\t\t}\r\n\t\treturn binary.toString();\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tString bs = printBinary(.125);\r\n\t\tSystem.out.println(bs);\r\n\t\t\r\n\t\tfor (int i = 0; i < 1000; i++) {\r\n\t\t\tdouble num = i / 1000.0;\r\n\t\t\tString binary = printBinary(num);\r\n\t\t\tString binary2 = printBinary2(num);\r\n\t\t\tif (!binary.equals(\"ERROR\") || !binary2.equals(\"ERROR\")) {\r\n\t\t\t\tSystem.out.println(num + \" : \" + binary + \" \" + binary2);\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_03_Flip_Bit_to_Win/QuestionA.java",
"content": "package Q5_03_Flip_Bit_to_Win;\n\npublic class QuestionA {\n\t\n\tpublic static int SEQUENCE_LENGTH = 32;\n\t\n\tpublic static boolean getBit(int num, int i) {\n\t\treturn ((num & (1 << i)) != 0);\n\t}\t\n\t\n\tpublic static int longestSequence(int n) {\n\t\tint maxSeq = 0;\n\t\t\n\t\tfor (int i = 0; i < SEQUENCE_LENGTH; i++) {\n\t\t\tmaxSeq = Math.max(maxSeq, longestSequenceOf1s(n, i));\n\t\t}\n\t\t\n\t\treturn maxSeq;\n\t}\n\t\n\tpublic static int longestSequenceOf1s(int n, int indexToIgnore) {\n\t\tint max = 0;\n\t\tint counter = 0;\n\t\tfor (int i = 0; i < SEQUENCE_LENGTH; i++) {\n\t\t\tif (i == indexToIgnore || getBit(n, i)) {\n\t\t\t\tcounter++;\n\t\t\t\tmax = Math.max(counter, max);\n\t\t\t} else {\n\t\t\t\tcounter = 0;\n\t\t\t}\n\t\t}\n\t\treturn max;\n\t}\t\n\t\n\tpublic static void main(String[] args) {\n\t\tint original_number = Integer.MAX_VALUE;\n\t\tint new_number = longestSequence(original_number);\n\t\t\t\n\t\tSystem.out.println(Integer.toBinaryString(original_number));\n\t\tSystem.out.println(new_number);\t\t\t\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_03_Flip_Bit_to_Win/QuestionB.java",
"content": "package Q5_03_Flip_Bit_to_Win;\n\nimport java.util.ArrayList;\n\npublic class QuestionB {\n\t\n\tpublic static int longestSequence(int n) {\n\t\tif (n == -1) return Integer.BYTES * 8;\n\t\tArrayList sequences = getAlternatingSequences(n);\n\t\treturn findLongestSequence(sequences);\n\t}\t\n\t\n\t/* Return a list of the sizes of the sequences. The sequence starts \n\t * off with the number of 0s (which might be 0) and then alternates\n\t * with the counts of each value.*/\n\tpublic static ArrayList getAlternatingSequences(int n) {\n\t\tArrayList sequences = new ArrayList();\n\t\t\n\t\tint searchingFor = 0;\n\t\tint counter = 0;\n\t\t\n\t\tfor (int i = 0; i < Integer.BYTES * 8; i++) {\n\t\t\tif ((n & 1) != searchingFor) {\n\t\t\t\tsequences.add(counter);\n\t\t\t\tsearchingFor = n & 1; // Flip 1 to 0 or 0 to 1\n\t\t\t\tcounter = 0;\t\n\t\t\t}\n\t\t\tcounter++;\n\t\t\tn >>>= 1;\n\t\t}\n\t\tsequences.add(counter);\n\t\t\n\t\treturn sequences;\n\t}\n\t\n\tpublic static int findLongestSequence(ArrayList seq) {\n\t\tint maxSeq = 1;\n\t\t\n\t\tfor (int i = 0; i < seq.size(); i += 2) {\n\t\t\tint zerosSeq = seq.get(i);\n\t\t\tint onesSeqPrev = i - 1 >= 0 ? seq.get(i - 1) : 0;\n\t\t\tint onesSeqNext = i + 1 < seq.size() ? seq.get(i + 1) : 0;\n\t\t\t\n\t\t\tint thisSeq = 0;\n\t\t\tif (zerosSeq == 1) { // Can merge\n\t\t\t\tthisSeq = onesSeqNext + 1 + onesSeqPrev; \n\t\t\t} else if (zerosSeq > 1) { // Just add a one to either side\n\t\t\t\tthisSeq = 1 + Math.max(onesSeqPrev, onesSeqNext);\n\t\t\t} else if (zerosSeq == 0) { // No zero, but take either side\n\t\t\t\tthisSeq = Math.max(onesSeqPrev, onesSeqNext);\n\t\t\t}\n\t\t\tmaxSeq = Math.max(thisSeq, maxSeq);\n\t\t}\n\t\t\n\t\treturn maxSeq;\n\t}\t\n\t\n\tpublic static void main(String[] args) {\n\t\tint original_number = 1775;\n\t\tint new_number = longestSequence(original_number);\n\t\t\t\n\t\tSystem.out.println(Integer.toBinaryString(original_number));\n\t\tSystem.out.println(new_number);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_03_Flip_Bit_to_Win/QuestionC.java",
"content": "package Q5_03_Flip_Bit_to_Win;\n\npublic class QuestionC {\n\n\tpublic static int SEQUENCE_LENGTH = 32;\n\t\n\t/* Given set of three sequences ordered as {0s, then 1s, then 0s}, \n\t * find max sequence that can be formed. */\n\tpublic static int getMaxSequence(int[] sequences) { /* 1s, then 0s, then [old] ones */\n\t\tif (sequences[1] == 1) { // a single 0 -> merge sequences\n\t\t\treturn sequences[0] + sequences[2] + 1; \n\t\t} else if (sequences[1] == 0) { // no 0s -> take one side\n\t\t\treturn Math.max(sequences[0], sequences[2]); \n\t\t} else { // many 0s -> take side, add 1 (flip a bit)\n\t\t\treturn Math.max(sequences[0], sequences[2]) + 1;\n\t\t}\n\t}\n\t\n\tpublic static void shift(int[] sequences) {\n\t\tsequences[2] = sequences[1];\n\t\tsequences[1] = sequences[0];\n\t\tsequences[0] = 0;\n\t}\n\t\n\tpublic static int longestSequence(int n) {\n\t\tint searchingFor = 0;\n\t\tint[] sequences = {0, 0, 0}; // Counts of last 3 sequences\n\t\tint maxSequence = 1;\n\t\t\n\t\tfor (int i = 0; i < SEQUENCE_LENGTH; i++) {\n\t\t\tif ((n & 1) != searchingFor) {\n\t\t\t\tif (searchingFor == 1) { // End of 1s + 0s + 1s sequence\n\t\t\t\t\tmaxSequence = Math.max(maxSequence, getMaxSequence(sequences));\n\t\t\t\t}\n\t\t\t\t\n\t\t\t\tsearchingFor = n & 1; // Flip 1 to 0 or 0 to 1\n\t\t\t\tshift(sequences); // Shift sequences\n\t\t\t}\n\t\t\tsequences[0]++;\n\t\t\tn >>>= 1;\n\t\t}\n\t\t\n\t\t/* Check final set of sequences */\n\t\tif (searchingFor == 0) {\n\t\t\tshift(sequences);\t\t\n\t\t}\n\t\tint finalSequence = getMaxSequence(sequences);\n\t\tmaxSequence = Math.max(finalSequence, maxSequence);\t\t\n\t\t\n\t\treturn maxSequence;\n\t}\t\t\n\t\n\tpublic static void main(String[] args) {\n\t\tint original_number = Integer.MAX_VALUE;\n\t\tint new_number = longestSequence(original_number);\n\t\t\t\n\t\tSystem.out.println(Integer.toBinaryString(original_number));\n\t\tSystem.out.println(new_number);\t\t\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_03_Flip_Bit_to_Win/QuestionD.java",
"content": "package Q5_03_Flip_Bit_to_Win;\n\npublic class QuestionD {\n\n\tpublic static int flipBit(int a) {\n\t\t/* If all 1s, this is already the longest sequence. */\n\t\tif (~a == 0) return Integer.BYTES * 8;\n\t\t\n\t\tint currentLength = 0;\n\t\tint previousLength = 0;\n\t\tint maxLength = 1; // We can always have a sequence of at least one 1\n\t\twhile (a != 0) {\n\t\t\tif ((a & 1) == 1) {\n\t\t\t\tcurrentLength++;\n\t\t\t} else if ((a & 1) == 0) {\n\t\t\t\t/* Update to 0 (if next bit is 0) or currentLength (if next bit is 1). */\n\t\t\t\tpreviousLength = (a & 2) == 0 ? 0 : currentLength;\n\t\t\t\tcurrentLength = 0;\n\t\t\t}\n\t\t\tmaxLength = Math.max(previousLength + currentLength + 1, maxLength);\n\t\t\ta >>>= 1;\n\t\t}\n\t\treturn maxLength;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint[][] cases = {{-1, 32}, {Integer.MAX_VALUE, 32}, {-10, 31}, {0, 1}, \n\t\t\t\t{1, 2}, {15, 5}, {1775, 8}};\n\t\tfor (int[] c : cases) {\n\t\t\tint x = flipBit(c[0]);\n\t\t\tboolean r = (c[1] == x);\n\t\t\tSystem.out.println(c[0] + \": \" + x + \", \" + c[1] + \" \" + r);\n\t\t}\n\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_03_Flip_Bit_to_Win/Tester.java",
"content": "package Q5_03_Flip_Bit_to_Win;\n\npublic class Tester {\n\t\n\tpublic static boolean checkRange(int start, int range) {\n\t\tfor (int i = 0; i < range; i++) {\n\t\t\tint value = start + i;\n\t\t\tint seqA = QuestionA.longestSequence(value);\n\t\t\tint seqB = QuestionB.longestSequence(value);\n\t\t\tint seqC = QuestionC.longestSequence(value);\n\t\t\tint seqD = QuestionC.longestSequence(value);\n\t\t\t\n\t\t\tif (seqA != seqB || seqB != seqC || seqC != seqD) {\n\t\t\t\tSystem.out.println(\"FAILURE on value \" + value);\n\t\t\t\tString xs = Integer.toBinaryString(value);\n\t\t\t\tSystem.out.println(xs);\n\t\t\t\tSystem.out.println(\"A: \" + seqA);\n\t\t\t\tSystem.out.println(\"B: \" + seqB);\n\t\t\t\tSystem.out.println(\"C: \" + seqC);\n\t\t\t\tSystem.out.println(\"D: \" + seqD);\n\t\t\t\treturn false;\n\t\t\t} \n\t\t}\n\t\treturn true;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint[][] ranges = {{Integer.MIN_VALUE, 1000}, {Integer.MAX_VALUE - 2333, 5333},\n\t\t\t\t{-10000, 20000}};\n\t\tfor (int[] range : ranges) {\n\t\t\tif (!checkRange(range[0], range[1])) {\n\t\t\t\tSystem.out.println(\"ERROR\");\n\t\t\t} else {\n\t\t\t\tint end = range[0] + range[1];\n\t\t\t\tSystem.out.println(\"SUCCESS: \" + range[0] + \" -> \" + end);\n\t\t\t}\n\t\t}\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_04_Next_Number/QuestionA.java",
"content": "package Q5_04_Next_Number;\r\n\r\npublic class QuestionA {\r\n\r\n\tpublic static int countOnes(int i) {\r\n\t\tint count = 0;\r\n\t\twhile (i > 0) {\r\n\t\t\tif ((i & 1) == 1) {\r\n\t\t\t\tcount++;\r\n\t\t\t}\r\n\t\t\ti = i >> 1;\r\n\t\t}\r\n\t\treturn count;\r\n\t}\r\n\t\r\n\tpublic static int countZeros(int i) {\r\n\t\treturn 32 - countOnes(i);\r\n\t}\t\r\n\t\r\n\tpublic static boolean hasValidNext(int i) {\r\n\t\tif (i == 0) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tint count = 0;\r\n\t\twhile ((i & 1) == 0) {\r\n\t\t\ti >>= 1;\r\n\t\t\tcount++;\r\n\t\t}\r\n\t\twhile ((i & 1) == 1) {\r\n\t\t\ti >>= 1;\r\n\t\t\tcount++;\r\n\t\t}\t\t\r\n\t\tif (count == 31) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn true;\t\r\n\t}\r\n\t\r\n\tpublic static boolean hasValidPrev(int i) {\r\n\t\twhile ((i & 1) == 1) {\r\n\t\t\ti >>= 1;\r\n\t\t}\r\n\t\tif (i == 0) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn true;\t\t\r\n\t}\r\n\r\n\tpublic static int getNextSlow(int i) {\r\n\t\tif (!hasValidNext(i)) {\r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\tint num_ones = countOnes(i);\r\n\t\ti++;\r\n\t\twhile (countOnes(i) != num_ones) {\r\n\t\t\ti++;\r\n\t\t}\r\n\t\treturn i;\r\n\t}\r\n\r\n\tpublic static int getPrevSlow(int i) {\r\n\t\tif (!hasValidPrev(i)) {\r\n\t\t\treturn -1;\r\n\t\t}\t\t\r\n\t\tint num_ones = countOnes(i);\r\n\t\ti--;\r\n\t\twhile (countOnes(i) != num_ones) {\r\n\t\t\ti--;\r\n\t\t}\r\n\t\treturn i;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint i = 13948;\r\n\t\tint p1 = getPrevSlow(i);\r\n\t\tint n1 = getNextSlow(i);\r\n\t\tTester.binPrint(p1);\r\n\t\tTester.binPrint(n1);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_04_Next_Number/QuestionB.java",
"content": "package Q5_04_Next_Number;\r\n\r\npublic class QuestionB {\r\n\t\r\n\tpublic static int getNext(int n) {\r\n\t\tint c = n;\r\n\t\tint c0 = 0;\r\n\t\tint c1 = 0;\r\n\t\twhile (((c & 1) == 0) && (c != 0)) {\r\n\t\t\tc0++;\r\n\t\t\tc >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\twhile ((c & 1) == 1) {\r\n\t\t\tc1++;\r\n\t\t\tc >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\t/* If c is 0, then n is a sequence of 1s followed by a sequence of 0s. This is already the biggest\r\n\t\t * number with c1 ones. Return error.\r\n\t\t */\r\n\t\tif (c0 + c1 == 31 || c0 + c1 == 0) {\r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\t\r\n\t\tint pos = c0 + c1; // position of right-most non-trailing zero (where the right most bit is bit 0)\r\n\t\t\r\n\t\t/* Flip the right-most non-trailing zero (which will be at position pos) */\r\n\t\tn |= (1 << pos); // Flip right-most non-trailing zero\r\n\t\t\t\t\r\n\t\t/* Clear all bits to the right of pos.\r\n\t\t * Example with pos = 5 \r\n\t\t * (1) Shift 1 over by 5 to create 0..0100000 [ mask = 1 << pos ]\r\n\t\t * (2) Subtract 1 to get 0..0011111 [ mask = mask - 1 ]\r\n\t\t * (3) Flip all the bits by using '~' to get 1..1100000 [ mask = ~mask ]\r\n\t\t * (4) AND with n\r\n\t\t */\r\n\t\tn &= ~((1 << pos) - 1); // Clear all bits to the right of pos\r\n\t\t\r\n\t\t/* Put (ones-1) 1s on the right by doing the following:\r\n\t\t * (1) Shift 1 over by (ones-1) spots. If ones = 3, this gets you 0..0100\r\n\t\t * (2) Subtract one from that to get 0..0011\r\n\t\t * (3) OR with n\r\n\t\t */\r\n\t\tn |= (1 << (c1 - 1)) - 1;\r\n\t\t\r\n\t\treturn n;\r\n\t}\r\n\t\r\n\tpublic static int getPrev(int n) {\r\n\t\tint temp = n;\r\n\t\tint c0 = 0;\r\n\t\tint c1 = 0;\r\n\t\twhile ((temp & 1) == 1) {\r\n\t\t\tc1++;\r\n\t\t\ttemp >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\t/* If temp is 0, then the number is a sequence of 0s followed by a sequence of 1s. This is already\r\n\t\t * the smallest number with c1 ones. Return -1 for an error.\r\n\t\t */\r\n\t\tif (temp == 0) { \r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\t\r\n\t\twhile (((temp & 1) == 0) && (temp != 0)) {\r\n\t\t\tc0++;\r\n\t\t\ttemp >>= 1;\r\n\t\t}\r\n\r\n\t\tint p = c0 + c1; // position of right-most non-trailing one (where the right most bit is bit 0)\r\n\r\n\t\t/* Flip right-most non-trailing one. \r\n\t\t * Example: n = 00011100011.\r\n\t\t * c1 = 2\r\n\t\t * c0 = 3\r\n\t\t * pos = 5\r\n\t\t * \r\n\t\t * Build up a mask as follows:\r\n\t\t * (1) ~0 will be a sequence of 1s\r\n\t\t * (2) shifting left by p + 1 will give you 11.111000000 (six 0s) \r\n\t\t * (3) ANDing with n will clear the last 6 bits\r\n\t\t * n is now 00011000000\r\n\t\t */\r\n\t\tn &= ((~0) << (p + 1)); // clears from bit p onwards (to the right)\r\n\t\t\r\n\t\t/* Create a sequence of (c1+1) 1s as follows\r\n\t\t * (1) Shift 1 to the left (c1+1) times. If c1 is 2, this will give you 0..001000\r\n\t\t * (2) Subtract one from that. This will give you 0..00111\r\n\t\t */\r\n\t\tint mask = (1 << (c1 + 1)) - 1; // Sequence of (c1+1) ones\r\n\t\t\r\n\t\t/* Move the ones to be right up next to bit p \r\n\t\t * Since this is a sequence of (c1+1) ones, and p = c1 + c0, we just need to\r\n\t\t * shift this over by (c0-1) spots.\r\n\t\t * If c0 = 3 and c1 = 2, then this will look like 00...0011100\r\n\t\t * \r\n\t\t * Then, finally, we OR this with n.\r\n\t\t */\r\n\t\tn |= mask << (c0 - 1); \r\n\t\t\r\n\t\treturn n;\t\t\r\n\t}\t\r\n\t\r\n\tpublic static void binPrint(int i) {\r\n\t\tSystem.out.println(i + \": \" + Integer.toBinaryString(i));\t\t\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint i = 13948;\r\n\t\tint p1 = getPrev(i);\r\n\t\tint n1 = getNext(i);\r\n\t\tTester.binPrint(p1);\r\n\t\tTester.binPrint(n1);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_04_Next_Number/QuestionC.java",
"content": "package Q5_04_Next_Number;\r\n\r\npublic class QuestionC {\r\n\tpublic static int getNextArith(int n) {\r\n\t\tint c = n;\r\n\t\tint c0 = 0;\r\n\t\tint c1 = 0;\r\n\t\twhile (((c & 1) == 0) && (c != 0)) {\r\n\t\t\tc0++;\r\n\t\t\tc >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\twhile ((c & 1) == 1) {\r\n\t\t\tc1++;\r\n\t\t\tc >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\t/* If c is 0, then n is a sequence of 1s followed by a sequence of 0s. This is already the biggest\r\n\t\t * number with c1 ones. Return error.\r\n\t\t */\r\n\t\tif (c0 + c1 == 31 || c0 + c1 == 0) {\r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\t\r\n\t\t/* Arithmetically:\r\n\t\t * 2^c0 = 1 << c0\r\n\t\t * 2^(c1-1) = 1 << (c0 - 1)\r\n\t\t * next = n + 2^c0 + 2^(c1-1) - 1;\r\n\t\t */\r\n\t\t\r\n\t\treturn n + (1 << c0) + (1 << (c1 - 1)) - 1;\r\n\t}\r\n\t\r\n\tpublic static int getPrevArith(int n) {\r\n\t\tint temp = n;\r\n\t\tint c0 = 0;\r\n\t\tint c1 = 0;\r\n\t\twhile (((temp & 1) == 1) && (temp != 0)) {\r\n\t\t\tc1++;\r\n\t\t\ttemp >>= 1;\r\n\t\t}\r\n\t\t\r\n\t\t/* If temp is 0, then the number is a sequence of 0s followed by a sequence of 1s. This is already\r\n\t\t * the smallest number with c1 ones. Return -1 for an error.\r\n\t\t */\r\n\t\tif (temp == 0) { \r\n\t\t\treturn -1;\r\n\t\t}\r\n\t\t\r\n\t\twhile ((temp & 1) == 0 && (temp != 0)) {\r\n\t\t\tc0++;\r\n\t\t\ttemp >>= 1;\r\n\t\t}\r\n\r\n\t\t/* Arithmetic:\r\n\t\t * 2^c1 = 1 << c1\r\n\t\t * 2^(c0 - 1) = 1 << (c0 - 1)\r\n\t\t */\r\n\t\treturn n - (1 << c1) - (1 << (c0 - 1)) + 1;\t\t\r\n\t}\t\r\n\t\r\n\tpublic static void binPrint(int i) {\r\n\t\tSystem.out.println(i + \": \" + Integer.toBinaryString(i));\t\t\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint i = 13948;\r\n\t\tint p1 = getPrevArith(i);\r\n\t\tint n1 = getNextArith(i);\r\n\t\tTester.binPrint(p1);\r\n\t\tTester.binPrint(n1);\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_04_Next_Number/Tester.java",
"content": "package Q5_04_Next_Number;\r\n\r\npublic class Tester {\r\n\tpublic static void binPrint(int i) {\r\n\t\tSystem.out.println(i + \": \" + Integer.toBinaryString(i));\t\t\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tfor (int i = 0; i < 200; i++) {\r\n\t\t\tint p1 = QuestionA.getPrevSlow(i);\r\n\t\t\tint p2 = QuestionB.getPrev(i);\r\n\t\t\tint p3 = QuestionC.getPrevArith(i);\r\n\t\t\t\r\n\t\t\tint n1 = QuestionA.getNextSlow(i);\r\n\t\t\tint n2 = QuestionB.getNext(i);\r\n\t\t\tint n3 = QuestionC.getNextArith(i);\r\n\t\t\t\r\n\t\t\tif (p1 != p2 || p2 != p3 || n1 != n2 || n2 != n3) {\r\n\t\t\t\tbinPrint(i);\r\n\t\t\t\tbinPrint(p1);\r\n\t\t\t\tbinPrint(p2);\r\n\t\t\t\tbinPrint(p3);\r\n\t\t\t\tbinPrint(n1);\r\n\t\t\t\tbinPrint(n2);\r\n\t\t\t\tbinPrint(n3);\r\n\t\t\t\tSystem.out.println(\"\");\r\n\t\t\t\tbreak;\r\n\t\t\t}\t\t\t\r\n\t\t}\r\n\t\tSystem.out.println(\"Done!\");\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_06_Conversion/QuestionA.java",
"content": "package Q5_06_Conversion;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionA {\r\n\tpublic static int bitSwapRequired(int a, int b) {\r\n\t\tint count = 0;\r\n\t\tint c = a ^ b;\r\n\t\twhile (c != 0) {\r\n\t\t\tcount += c & 1; // Increment count if c ends with a 1\r\n\t\t\tc >>>= 1; // Shift right by 1\r\n\t\t}\r\n\t\treturn count;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint a = -23432;\r\n\t\tint b = 512132;\r\n\t\tSystem.out.println(a + \": \" + AssortedMethods.toFullBinaryString(a));\r\n\t\tSystem.out.println(b + \": \" + AssortedMethods.toFullBinaryString(b));\r\n\t\tSystem.out.println(\"Required number of bits: \" + bitSwapRequired(a, b));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_06_Conversion/QuestionB.java",
"content": "package Q5_06_Conversion;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class QuestionB {\r\n\tpublic static int bitSwapRequired(int a, int b){\r\n\t\tint count = 0;\r\n\t\tint c = a ^ b;\r\n\r\n\t\tSystem.out.println(\"****\");\r\n\t\tSystem.out.println(c + \": \" + AssortedMethods.toFullBinaryString(c));\r\n\t\twhile (c != 0) {\r\n\t\t\tSystem.out.println(\"c - 1: \" + c + \": \" + AssortedMethods.toFullBinaryString(c - 1));\r\n\t\t\tc = c & (c-1);\r\n\t\t\tSystem.out.println(\"c: \" + c + \": \" + AssortedMethods.toFullBinaryString(c));\r\n\t\t\tcount++;\r\n\t\t\tSystem.out.println(\"****\");\r\n\t\t}\r\n\t\treturn count;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint a = -23432;\r\n\t\tint b = 512132;\r\n\t\tSystem.out.println(a + \": \" + AssortedMethods.toFullBinaryString(a));\r\n\t\tSystem.out.println(b + \": \" + AssortedMethods.toFullBinaryString(b));\r\n\t\tSystem.out.println(\"Required number of bits: \" + bitSwapRequired(a, b));\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_06_Conversion/Tester.java",
"content": "package Q5_06_Conversion;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Tester {\r\n\tpublic static int bitSwapRequired(int a, int b) {\r\n\t\tint count = 0;\r\n\t\tfor (int c = a ^ b; c != 0; c = c >>> 1) { \r\n\t\t\tcount += c & 1;\r\n\t\t}\r\n\t\treturn count;\r\n\t}\r\n\t\r\n\tpublic static int bitSwapRequired2(int a, int b){\r\n\t\tint count = 0;\r\n\t\tfor (int c = a ^ b; c != 0; c = c & (c-1)) {\r\n\t\t\tcount++;\r\n\t\t}\r\n\t\treturn count;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint a = -23432;\r\n\t\tint b = 512132;\r\n\t\tSystem.out.println(a + \": \" + AssortedMethods.toFullBinaryString(a));\r\n\t\tSystem.out.println(b + \": \" + AssortedMethods.toFullBinaryString(b));\r\n\t\tint nbits = QuestionA.bitSwapRequired(a, b);\r\n\t\tint nbits2 = QuestionB.bitSwapRequired(a, b);\r\n\t\tSystem.out.println(\"Required number of bits: \" + nbits + \" \" + nbits2);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_07_Pairwise_Swap/Question.java",
"content": "package Q5_07_Pairwise_Swap;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\r\n\tpublic static int swapOddEvenBits(int x) { \r\n\t\treturn ( ((x & 0xaaaaaaaa) >>> 1) | ((x & 0x55555555) << 1) ); \r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint a = 234321;\r\n\t\tSystem.out.println(a + \": \" + AssortedMethods.toFullBinaryString(a));\r\n\t\tint b = swapOddEvenBits(a);\r\n\t\tSystem.out.println(b + \": \" + AssortedMethods.toFullBinaryString(b));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Q5_08_Draw_Line/Question.java",
"content": "package Q5_08_Draw_Line;\r\n\r\npublic class Question {\r\n\tpublic static int computeByteNum(int width, int x, int y) {\r\n\t\treturn (width * y + x) / 8;\r\n\t}\r\n\t\r\n\tpublic static void drawLine(byte[] screen, int width, int x1, int x2, int y) {\r\n\t\tint start_offset = x1 % 8;\r\n\t\tint first_full_byte = x1 / 8;\r\n\t\tif (start_offset != 0) {\r\n\t\t\tfirst_full_byte++;\r\n\t\t}\r\n\t\t\r\n\t\tint end_offset = x2 % 8;\r\n\t\tint last_full_byte = x2 / 8;\r\n\t\tif (end_offset != 7) {\r\n\t\t\tlast_full_byte--;\r\n\t\t}\r\n\t\t\r\n\t\t// Set full bytes\r\n\t\tfor (int b = first_full_byte; b <= last_full_byte; b++) {\r\n\t\t\tscreen[(width / 8) * y + b] = (byte) 0xFF;\r\n\t\t}\r\n\t\t\r\n\t\tbyte start_mask = (byte) (0xFF >> start_offset);\r\n\t\tbyte end_mask = (byte) ~(0xFF >> (end_offset + 1));\r\n\t\t\r\n\t\t// Set start and end of line\r\n\t\tif ((x1 / 8) == (x2 / 8)) { // If x1 and x2 are in the same byte\r\n\t\t\tbyte mask = (byte) (start_mask & end_mask);\r\n\t\t\tscreen[(width / 8) * y + (x1 / 8)] |= mask;\r\n\t\t} else {\r\n\t\t\tif (start_offset != 0) {\r\n\t\t\t\tint byte_number = (width / 8) * y + first_full_byte - 1;\r\n\t\t\t\tscreen[byte_number] |= start_mask;\r\n\t\t\t}\r\n\t\t\tif (end_offset != 7) {\r\n\t\t\t\tint byte_number = (width / 8) * y + last_full_byte + 1;\r\n\t\t\t\tscreen[byte_number] |= end_mask;\r\n\t\t\t} \r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void printByte(byte b) {\r\n\t\tfor (int i = 7; i >= 0; i--) {\r\n\t\t\tchar c = ((b >> i) & 1) == 1 ? '1' : '_';\r\n\t\t\tSystem.out.print(c);\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void printScreen(byte[] screen, int width) {\r\n\t\tint height = screen.length * 8 / width;\r\n\t\tfor (int r = 0; r < height; r++) {\r\n\t\t\tfor (int c = 0; c < width; c+=8) {\r\n\t\t\t\tbyte b = screen[computeByteNum(width, c, r)];\r\n\t\t\t\tprintByte(b);\r\n\t\t\t}\r\n\t\t\tSystem.out.println(\"\");\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tint width = 8 * 1;\r\n\t\tint height = 1;\r\n\t\tfor (int r = 0; r < height; r++) {\r\n\t\t\tfor (int c1 = 0; c1 < width; c1++) {\r\n\t\t\t\tfor (int c2 = c1; c2 < width; c2++) {\r\n\t\t\t\t\tbyte[] screen = new byte[width * height / 8];\r\n\r\n\t\t\t\t\tSystem.out.println(\"row: \" + r + \": \" + c1 + \" -> \" + c2);\r\n\t\t\t\t\tdrawLine(screen, width, c1, c2, r);\r\n\t\t\t\t\tprintScreen(screen, width);\r\n\t\t\t\t\tSystem.out.println(\"\\n\\n\");\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Sample_Code/RightShifts.java",
"content": "package Sample_Code;\n\nimport CtCILibrary.AssortedMethods;\n\npublic class RightShifts {\n\tpublic static int repeatedArithmeticShift(int x, int count) {\n\t\tfor (int i = 0; i < count; i++) {\n\t\t\tx >>= 1; // Arithmetic shift by 1\n\t\t}\n\t\treturn x;\n\t}\n\t\n\tpublic static int repeatedLogicalShift(int x, int count) {\n\t\tfor (int i = 0; i < count; i++) {\n\t\t\tx >>>= 1; // Logical shift by 1\n\t\t}\n\t\treturn x;\n\t}\t\n\t\n\tpublic static void main(String[] args) {\n\t\tfor (int i = 8; i >= -8; i--) {\n\t\t\tSystem.out.println(AssortedMethods.toFullBinaryString(i) + \": \" + i);\n\t\t}\n\t\t\n\t\tint x = -93242;\n\t\tint resultArithmetic = repeatedArithmeticShift(x, 40);\n\t\tint resultLogical = repeatedLogicalShift(x, 40);\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(resultArithmetic) + \": \" + resultArithmetic);\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(resultLogical) + \": \" + resultLogical);\n\t}\n\n}\n"
},
{
"path": "Java/Ch 05. Bit Manipulation/Sample_Code/Sample_Code.java",
"content": "package Sample_Code;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Sample_Code {\r\n\r\n\tpublic static boolean getBit(int num, int i) {\r\n\t\treturn ((num & (1 << i)) != 0);\r\n\t}\r\n\t\r\n\tpublic static int setBit(int num, int i) {\r\n\t\treturn num | (1 << i);\r\n\t}\r\n\t\r\n\tpublic static int clearBit(int num, int i) {\r\n\t\tint mask = ~(1 << i);\r\n\t\treturn num & mask;\r\n\t}\r\n\t\r\n\tpublic static int updateBit(int num, int i, boolean bitIs1) {\r\n\t\tint value = bitIs1 ? 1 : 0;\r\n\t\tint mask = ~(1 << i);\r\n\t\treturn (num & mask) | (value << i);\r\n\t}\r\n\t\r\n\tpublic static int clearBitsMSBthroughI(int num, int i) {\r\n\t\tint mask = (1 << i) - 1;\r\n\t\treturn num & mask;\r\n\t}\r\n\t\r\n\tpublic static int clearBitsIthrough0(int num, int i) {\r\n\t\tint mask = (-1 << (i+1));\r\n\t\treturn num & mask;\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\t\r\n\t\tint number = 59;\r\n\t\tSystem.out.println(\"Testing with number: \" + number);\r\n\t\t\r\n\t\t// Get Bit\r\n\t\tSystem.out.println(\"Get Bit\");\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(number));\r\n\t\tfor (int i = 31; i >= 0; i--) {\r\n\t\t\tint res = getBit(number, i) ? 1 : 0;\r\n\t\t\tSystem.out.print(res);\r\n\t\t}\r\n\t\t\r\n\t\t// Update Bit\r\n\t\tSystem.out.println(\"\\n\\nUpdate Bit\");\t\t\r\n\t\tint num1 = 1578; // arbitrary number\r\n\t\tfor (int i = 31; i >= 0; i--) {\r\n\t\t\tnum1 = updateBit(num1, i, getBit(number, i));\r\n\t\t}\t\r\n\t\tSystem.out.println(num1);\r\n\t\t\r\n\t\t// Set and Clear Bit\r\n\t\tSystem.out.println(\"\\nSet and Clear Bit\");\t\t\r\n\t\tint num2 = 1578; // arbitrary number\r\n\t\tfor (int i = 31; i >= 0; i--) {\r\n\t\t\tif (getBit(number, i)) {\r\n\t\t\t\tnum2 = setBit(num2, i);\r\n\t\t\t} else {\r\n\t\t\t\tnum2 = clearBit(num2, i);\r\n\t\t\t}\r\n\t\t}\t\r\n\t\tSystem.out.println(num2);\r\n\t\r\n\t\t// Clear Bits MSB through i\r\n\t\tnumber = 13242352;\r\n\t\tint clearMSBThrough = 4;\r\n\t\tSystem.out.println(\"\\nClear bits MSB through \" + clearMSBThrough);\t\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(number));\r\n\t\tint num3 = clearBitsMSBthroughI(number, clearMSBThrough);\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(num3));\r\n\t\t\r\n\t\t// Clear Bits i through 0\r\n\t\tint clearToLSB = 2;\r\n\t\tSystem.out.println(\"\\nClear bits \" + clearToLSB + \" through 0\");\t\r\n\t\tnumber = -1;\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(number));\r\n\t\tint num4 = clearBitsIthrough0(number, clearToLSB);\r\n\t\tSystem.out.println(AssortedMethods.toFullBinaryString(num4));\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Introduction/PrimeNumbers.java",
"content": "package Introduction;\r\n\r\npublic class PrimeNumbers {\r\n\r\n\tpublic static boolean primeNaive(int n) {\r\n\t\tfor (int i = 2; i < n; i++) {\r\n\t\t\tif (n % i == 0) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic static boolean primeSlightlyBetter(int n) {\r\n\t\tint sqrt = (int) Math.sqrt(n);\r\n\t\tfor (int i = 2; i <= sqrt; i++) {\r\n\t\t\tif (n % i == 0) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn true;\r\n\t}\t\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tfor (int i = 2; i < 100; i++) {\r\n\t\t\tif (primeSlightlyBetter(i)) {\r\n\t\t\t\tSystem.out.println(i);\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Introduction/SieveOfEratosthenes.java",
"content": "package Introduction;\r\n\r\npublic class SieveOfEratosthenes {\r\n\t\r\n\tpublic static void crossOff(boolean[] flags, int prime) {\r\n\t\t/* Cross off remaining multiples of prime. We can start with\r\n\t\t * (prime*prime), because if we have a k * prime, where k < prime,\r\n\t\t * this value would have already been crossed off in a prior\r\n\t\t * iteration. */\t\t\r\n\t\tfor (int i = prime * prime; i < flags.length; i += prime) {\r\n\t\t\tflags[i] = false;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static int getNextPrime(boolean[] flags, int prime) {\r\n\t\tint next = prime + 1;\r\n\t\twhile (next < flags.length && !flags[next]) {\r\n\t\t\tnext++;\r\n\t\t}\r\n\t\treturn next;\t\r\n\t}\r\n\t\r\n\tpublic static void init(boolean[] flags) {\r\n\t\tflags[0] = false;\r\n\t\tflags[1] = false;\r\n\t\tfor (int i = 2; i < flags.length; i++) {\r\n\t\t\tflags[i] = true;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic static int[] prune(boolean[] flags, int count) {\r\n\t\tint[] primes = new int[count];\r\n\t\tint index = 0;\r\n\t\tfor (int i = 0; i < flags.length; i++) {\r\n\t\t\tif (flags[i]) {\r\n\t\t\t\tprimes[index] = i;\r\n\t\t\t\tindex++;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn primes;\r\n\t}\r\n\t\r\n\tpublic static boolean[] sieveOfEratosthenes(int max) {\r\n boolean[] flags = new boolean[max + 1];\r\n \r\n\t\tinit(flags);\r\n int prime = 2;\r\n \r\n while (prime <= Math.sqrt(max)) { \t\r\n \t\t/* Cross off remaining multiples of prime */ \r\n \t\tcrossOff(flags, prime); \r\n\r\n \t\t/* Find next value which is true */\r\n \t\tprime = getNextPrime(flags, prime);\r\n }\r\n \r\n return flags; //prune(flags, count);\r\n\t}\r\n\t\r\n\tpublic static void main(String[] args) {\r\n\t\tboolean[] primes = sieveOfEratosthenes(4);\r\n\t\tfor (int i = 0; i < primes.length; i++) {\r\n\t\t\tif (primes[i]) {\r\n\t\t\t\tSystem.out.println(i);\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_05_Egg_Drop/Question.java",
"content": "package Q6_05_Egg_Drop;\n\npublic class Question {\n\tpublic static int breakingPoint = 89;\n\tpublic static int countDrops = 0;\n\n\n\tpublic static boolean willBreak(int floor) {\n\t\tcountDrops++;\n\t\treturn floor >= breakingPoint;\n\t}\n\n\n\tpublic static int findBreakingPoint(int floors) {\n\t\tint interval = 14;\n\t\tint previousFloor = 0;\n\t\tint egg1 = interval;\n\t\t\n\t\t/* Drop egg1 at decreasing intervals. */\n\t\twhile (!willBreak(egg1) && egg1 <= floors) {\n\t\t\tinterval -= 1;\n\t\t\tpreviousFloor = egg1;\n\t\t\tegg1 += interval;\n\t\t}\n\t\t\n\t\t/* Drop egg2 at 1 unit increments. */\n\t\tint egg2 = previousFloor + 1;\n\t\twhile (egg2 < egg1 && egg2 <= floors && !willBreak(egg2)) {\n\t\t\tegg2 += 1;\n\t\t}\n\t\t\n\t\t/* If it didn’t break, return -1. */\n\t\treturn egg2 > floors ? -1 : egg2;\n\t}\n\n\n\tpublic static void main(String[] args) {\n\t\tint max = 0;\n\t\tfor (int i = 1; i <= 100; i++) {\n\t\t\tcountDrops = 0;\n\t\t\tbreakingPoint = i;\n\t\t\tint bp = findBreakingPoint(100);\n\t\t\t\n\t\t\tif (bp == breakingPoint) {\n\t\t\t\tSystem.out.println(\"SUCCESS: \" + i + \" -> \" + bp + \" -> \" + countDrops);\n\t\t\t} else {\n\t\t\t\tSystem.out.println(\"ERROR: \" + i + \" -> \" + bp + \" vs \" + breakingPoint);\n\t\t\t\tbreak;\n\t\t\t}\n\t\t\tmax = countDrops > max ? countDrops : max;\n\t\t}\n\t\tSystem.out.println(max);\n\t}\n}\n\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_07_The_Apocalypse/Question.java",
"content": "package Q6_07_The_Apocalypse;\n\nimport java.util.Random;\n\npublic class Question {\n\tpublic static int[] runOneFamily() {\n\t\tRandom random = new Random();\n\t\tint boys = 0;\n\t\tint girls = 0;\n\t\twhile (girls == 0) { // until we have a girl\n\t\t\tif (random.nextBoolean()) { // girl\n\t\t\t\tgirls += 1;\n\t\t\t} else { // boy\n\t\t\t\tboys += 1;\n\t\t\t}\n\t\t}\n\t\tint[] genders = {girls, boys};\n\t\treturn genders;\n\t}\n\t\n\tpublic static double runNFamilies(int n) {\n\t\tint boys = 0;\n\t\tint girls = 0;\n\t\tfor (int i = 0; i < n; i++) {\n\t\t\tint[] genders = runOneFamily();\n\t\t\tgirls += genders[0];\n\t\t\tboys += genders[1];\n\t\t}\n\t\treturn girls / (double) (boys + girls); \n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tdouble ratio = runNFamilies(10000000);\n\t\tSystem.out.println(ratio);\n\n\t}\n\n}\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_10_Test_Strips/Bottle.java",
"content": "package Q6_10_Test_Strips;\n\npublic class Bottle {\n\tprivate boolean poisoned = false;\n\tprivate int id;\n\t\n\tpublic Bottle(int id) {\n\t\tthis.id = id;\n\t}\n\t\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\t\n\tpublic void setAsPoisoned() {\n\t\tpoisoned = true;\n\t}\n\t\n\tpublic boolean isPoisoned() {\n\t\treturn poisoned;\n\t}\n}\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_10_Test_Strips/QuestionA.java",
"content": "package Q6_10_Test_Strips;\n\nimport java.util.ArrayList;\nimport java.util.Random;\n\npublic class QuestionA {\n\tpublic static int findPoisonedBottle(ArrayList bottles, ArrayList strips) {\n\t\tint today = 0;\n\t\t\n\t\twhile (bottles.size() > 1 && strips.size() > 0) {\n\t\t\t/* Run tests. */\n\t\t\trunTestSet(bottles, strips, today);\n\t\t\t\n\t\t\t/* Wait for results. */\n\t\t\ttoday += TestStrip.DAYS_FOR_RESULT;\n\t\t\t\n\t\t\t/* Check results. */\n\t\t\tfor (TestStrip strip : strips) {\n\t\t\t\tif (strip.isPositiveOnDay(today)) {\n\t\t\t\t\tbottles = strip.getLastWeeksBottles(today);\n\t\t\t\t\tstrips.remove(strip);\n\t\t\t\t\tbreak;\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t\n\t\tif (bottles.size() == 1) {\n\t\t\tSystem.out.println(\"Suspected bottle is \" + bottles.get(0).getId() + \" on day \" + today);\n\t\t\treturn bottles.get(0).getId();\n\t\t}\n\t\treturn -1;\t\n\t}\t\n\t\n\tpublic static void runTestSet(ArrayList bottles, ArrayList strips, int day) {\n\t\tint index = 0;\n\t\tfor (Bottle bottle : bottles) {\n\t\t\tTestStrip strip = strips.get(index);\n\t\t\tstrip.addDropOnDay(day, bottle);\n\t\t\tindex = (index + 1) % strips.size();\n\t\t}\n\t}\n\t\n\tpublic static ArrayList createBottles(int nBottles, int poisoned) {\n\t\tArrayList bottles = new ArrayList();\n\t\tfor (int i = 0; i < nBottles; i++) {\n\t\t\tbottles.add(new Bottle(i));\n\t\t}\n\t\t\n\t\tif (poisoned == -1) {\n\t\t\tRandom random = new Random();\n\t\t\tpoisoned = random.nextInt(nBottles);\n\t\t}\n\t\tbottles.get(poisoned).setAsPoisoned();\n\t\t\n\t\tSystem.out.println(\"Added poison to bottle \" + poisoned);\n\t\t\n\t\treturn bottles;\n\t}\n\t\n\tpublic static ArrayList createTestStrips(int nTestStrips) {\n\t\tArrayList testStrips = new ArrayList();\n\t\tfor (int i = 0; i < nTestStrips; i++) {\n\t\t\ttestStrips.add(new TestStrip(i));\n\t\t}\n\t\treturn testStrips;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint nBottles = 1000;\n\t\tint nTestStrips = 10;\n\t\tfor (int poisoned = 0; poisoned < nBottles; poisoned++) {\n\t\t\tArrayList bottles = createBottles(nBottles, poisoned);\n\t\t\tArrayList testStrips = createTestStrips(nTestStrips);\n\t\t\tint poisonedId = findPoisonedBottle(bottles, testStrips);\n\t\t\tSystem.out.println(\"Suspected Bottle: \" + poisonedId);\n\t\t\tif (poisonedId != poisoned) {\n\t\t\t\tSystem.out.println(\"ERROR\");\n\t\t\t\tbreak;\n\t\t\t}\n\t\t}\n\t}\n}\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_10_Test_Strips/QuestionB.java",
"content": "package Q6_10_Test_Strips;\n\nimport java.util.ArrayList;\nimport java.util.HashSet;\nimport java.util.Random;\n\npublic class QuestionB {\n\tpublic static ArrayList createBottles(int nBottles, int poisoned) {\n\t\tArrayList bottles = new ArrayList();\n\t\tfor (int i = 0; i < nBottles; i++) {\n\t\t\tbottles.add(new Bottle(i));\n\t\t}\n\t\t\n\t\tif (poisoned == -1) {\n\t\t\tRandom random = new Random();\n\t\t\tpoisoned = random.nextInt(nBottles);\n\t\t}\n\t\tbottles.get(poisoned).setAsPoisoned();\n\t\t\n\t\tSystem.out.println(\"Added poison to bottle \" + poisoned);\n\t\t\n\t\treturn bottles;\n\t}\n\n\tpublic static int findPoisonedBottle(ArrayList bottles, ArrayList strips) {\n\t\tif (bottles.size() > 1000 || strips.size() < 10) return -1;\n\t\t\n\t\tint tests = 4; // three digits, plus one extra\n\t\tint nTestStrips = strips.size();\n\t\t\n\t\t/* Run tests. */\n\t\tfor (int day = 0; day < tests; day++) {\n\t\t\trunTestSet(bottles, strips, day);\n\t\t}\n\t\t\n\t\t/* Get results. */\n\t\tHashSet previousResults = new HashSet();\n\t\tint[] digits = new int[tests];\n\t\tfor (int day = 0; day < tests; day++) {\n\t\t\tint resultDay = day + TestStrip.DAYS_FOR_RESULT;\n\t\t\tdigits[day] = getPositiveOnDay(strips, resultDay, previousResults);\n\t\t\tpreviousResults.add(digits[day]);\n\t\t}\n\t\t\n\t\t/* If day 1's results matched day 0's, update the digit. */\n\t\tif (digits[1] == -1) {\n\t\t\tdigits[1] = digits[0];\n\t\t}\n\t\t\n\t\t/* If day 2 matched day 0 or day 1, check day 3. Day 3 is\n\t\t * the same as day 2, but incremented by 1. */\n\t\tif (digits[2] == -1) { \n\t\t\tif (digits[3] == -1) { /* Day 3 didn't give new result */\n\t\t\t\t/* Digit 2 equals digit 0 or digit 1. But, digit 2, when incremented also matches \n\t\t\t\t * digit 0 or digit 1. This means that digit 0 incremented matches digit 1, or the\n\t\t\t\t * other way around. */\n\t\t\t\tdigits[2] = ((digits[0] + 1) % nTestStrips) == digits[1] ? digits[0] : digits[1]; \n\t\t\t} else {\n\t\t\t\tdigits[2] = (digits[3] - 1 + nTestStrips) % nTestStrips;\n\t\t\t}\n\t\t}\n\t\t\n\t\treturn digits[0] * 100 + digits[1] * 10 + digits[2];\n\t}\n\t\n\t/* Run set of tests for this day. */\n\tpublic static void runTestSet(ArrayList bottles, ArrayList strips, int day) {\n\t\tif (day > 3) return; // only works for 3 days (digits) + one extra\n\n\t\tfor (Bottle bottle : bottles) {\n\t\t\tint index = getTestStripIndexForDay(bottle, day, strips.size());\n\t\t\tTestStrip testStrip = strips.get(index);\n\t\t\ttestStrip.addDropOnDay(day, bottle);\n\t\t}\n\t}\n\t\n\t/* Get test strip index that should be used on this bottle on this day. */ \n\tpublic static int getTestStripIndexForDay(Bottle bottle, int day, int nTestStrips) {\n\t\tint id = bottle.getId();\n\t\tswitch (day) {\n\t\t\tcase 0: return id /100;\n\t\t\tcase 1: return (id % 100) / 10;\n\t\t\tcase 2: return id % 10;\n\t\t\tcase 3: return (id % 10 + 1) % nTestStrips;\n\t\t\tdefault: return -1;\n\t\t}\n\t}\t\n\t\n\t/* Get results that are positive for a particular day, excluding prior results. */\n\tpublic static int getPositiveOnDay(ArrayList testStrips, int day, HashSet previousResults) {\n\t\tfor (TestStrip testStrip : testStrips) {\n\t\t\tint id = testStrip.getId();\n\t\t\tif (testStrip.isPositiveOnDay(day) && !previousResults.contains(id)) {\n\t\t\t\treturn testStrip.getId();\n\t\t\t}\n\t\t}\n\t\treturn -1;\n\t}\t\n\t\n\tpublic static ArrayList createTestStrips(int nTestStrips) {\n\t\tArrayList testStrips = new ArrayList();\n\t\tfor (int i = 0; i < nTestStrips; i++) {\n\t\t\ttestStrips.add(new TestStrip(i));\n\t\t}\n\t\treturn testStrips;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint nBottles = 1000;\n\t\tint nTestStrips = 10;\n\t\tfor (int poisoned = 0; poisoned < nBottles; poisoned++) {\n\t\t\tArrayList bottles = createBottles(nBottles, poisoned);\n\t\t\tArrayList testStrips = createTestStrips(nTestStrips);\n\t\t\tint poisonedId = findPoisonedBottle(bottles, testStrips);\n\t\t\tSystem.out.println(\"Suspected Bottle: \" + poisonedId);\n\t\t\tif (poisonedId != poisoned) {\n\t\t\t\tSystem.out.println(\"ERROR\");\n\t\t\t\tbreak;\n\t\t\t}\n\t\t}\n\t}\n}\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_10_Test_Strips/QuestionC.java",
"content": "package Q6_10_Test_Strips;\n\nimport java.util.ArrayList;\nimport java.util.Random;\n\npublic class QuestionC {\n\tpublic static ArrayList createBottles(int nBottles, int poisoned) {\n\t\tArrayList bottles = new ArrayList();\n\t\tfor (int i = 0; i < nBottles; i++) {\n\t\t\tbottles.add(new Bottle(i));\n\t\t}\n\t\t\n\t\tif (poisoned == -1) {\n\t\t\tRandom random = new Random();\n\t\t\tpoisoned = random.nextInt(nBottles);\n\t\t}\n\t\tbottles.get(poisoned).setAsPoisoned();\n\t\t\n\t\tSystem.out.println(\"Added poison to bottle \" + poisoned);\n\t\t\n\t\treturn bottles;\n\t}\n\t\n\tpublic static int findPoisonedBottle(ArrayList bottles, ArrayList strips) {\n\t\trunTests(bottles, strips);\n\t\tArrayList positive = getPositiveOnDay(strips, 7);\n\t\treturn setBits(positive);\n\t}\t\n\t\n\t/* Add bottles to test strips */\n\tpublic static void runTests(ArrayList bottles, ArrayList testStrips) {\n\t\tfor (Bottle bottle : bottles) {\n\t\t\tint id = bottle.getId();\n\t\t\tint bitIndex = 0;\n\t\t\twhile (id > 0) {\n\t\t\t\tif ((id & 1) == 1) {\n\t\t\t\t\ttestStrips.get(bitIndex).addDropOnDay(0, bottle);\n\t\t\t\t}\n\t\t\t\tbitIndex++;\n\t\t\t\tid >>= 1;\n\t\t\t}\n\t\t}\n\t}\n\t\n\t/* Get test strips that are positive on a particular day. */\n\tpublic static ArrayList getPositiveOnDay(ArrayList testStrips, int day) {\n\t\tArrayList positive = new ArrayList();\n\t\tfor (TestStrip testStrip : testStrips) {\n\t\t\tint id = testStrip.getId();\n\t\t\tif (testStrip.isPositiveOnDay(day)) {\n\t\t\t\tpositive.add(id);\n\t\t\t}\n\t\t}\n\t\treturn positive;\n\t}\n\t\n\t/* Create number by setting bits with indices specified in positive. */\n\tpublic static int setBits(ArrayList positive) {\n\t\tint id = 0;\n\t\tfor (Integer bitIndex : positive) {\n\t\t\tid |= 1 << bitIndex;\n\t\t}\n\t\treturn id;\n\t}\n\t\n\tpublic static ArrayList createTestStrips(int nTestStrips) {\n\t\tArrayList testStrips = new ArrayList();\n\t\tfor (int i = 0; i < nTestStrips; i++) {\n\t\t\ttestStrips.add(new TestStrip(i));\n\t\t}\n\t\treturn testStrips;\n\t}\n\t\n\tpublic static void main(String[] args) {\n\t\tint nBottles = 1000;\n\t\tint nTestStrips = 10;\n\t\tfor (int poisoned = 0; poisoned < nBottles; poisoned++) {\n\t\t\tArrayList bottles = createBottles(nBottles, poisoned);\n\t\t\tArrayList testStrips = createTestStrips(nTestStrips);\n\t\t\tint poisonedId = findPoisonedBottle(bottles, testStrips);\n\t\t\tSystem.out.println(\"Suspected Bottle: \" + poisonedId);\n\t\t\tif (poisonedId != poisoned) {\n\t\t\t\tSystem.out.println(\"ERROR\");\n\t\t\t\tbreak;\n\t\t\t}\n\t\t}\n\t}\n}\n"
},
{
"path": "Java/Ch 06. Math and Logic Puzzles/Q6_10_Test_Strips/TestStrip.java",
"content": "package Q6_10_Test_Strips;\n\nimport java.util.ArrayList;\n\npublic class TestStrip {\n\tpublic static int DAYS_FOR_RESULT = 7; \n\tprivate ArrayList> dropsByDay = new ArrayList>();\n\tprivate int id;\n\t\n\tpublic TestStrip(int id) {\n\t\tthis.id = id;\n\t}\n\t\n\tpublic int getId() {\n\t\treturn id;\n\t}\n\t\n\t/* Resize list of days/drops to be large enough. */\n\tprivate void sizeDropsForDay(int day) {\n\t\twhile (dropsByDay.size() <= day) {\n\t\t\tdropsByDay.add(new ArrayList());\n\t\t}\n\t}\n\t\n\t/* Add drop from bottle on specific day. */\n\tpublic void addDropOnDay(int day, Bottle bottle) {\n\t\tsizeDropsForDay(day);\n\t\tArrayList drops = dropsByDay.get(day);\n\t\tdrops.add(bottle);\n\t}\n\t\n\t/* Checks if any of the bottles in the set are poisoned. */\n\tprivate boolean hasPoison(ArrayList bottles) {\n\t\tfor (Bottle b : bottles) {\n\t\t\tif (b.isPoisoned()) {\n\t\t\t\treturn true;\n\t\t\t}\n\t\t}\n\t\treturn false;\n\t}\n\t\n\t/* Gets bottles that were used in the test DAYS_FOR_RESULT days ago. */ \n\tpublic ArrayList getLastWeeksBottles(int day) {\n\t\tif (day < DAYS_FOR_RESULT) {\n\t\t\treturn null;\n\t\t}\n\t\treturn dropsByDay.get(day - DAYS_FOR_RESULT);\n\t}\n\t\n\t/* Checks if the test strip has had any poisoned bottles since before DAYS_FOR_RESULT */\n\tpublic boolean isPositiveOnDay(int day) {\n\t\tint testDay = day - DAYS_FOR_RESULT;\n\t\tif (testDay < 0 || testDay >= dropsByDay.size()) {\n\t\t\treturn false;\n\t\t}\n\t\tfor (int d = 0; d <= testDay; d++) {\n\t\t\tArrayList bottles = dropsByDay.get(d);\n\t\t\tif (hasPoison(bottles)) {\n\t\t\t\treturn true;\n\t\t\t}\n\t\t}\n\t\treturn false;\n\t}\n}\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/BlackJackCard.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\npublic class BlackJackCard extends Card {\r\n\tpublic BlackJackCard(int c, Suit s) {\r\n\t\tsuper(c, s);\r\n\t}\r\n\t\r\n\tpublic int value() {\r\n\t\tif (isAce()) { // Ace\r\n\t\t\treturn 1; \r\n\t\t} else if (isFaceCard()) { // Face card\r\n\t\t\treturn 10;\r\n\t\t} else { // Number card\r\n\t\t\treturn faceValue;\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic int minValue() {\r\n\t\tif (isAce()) { // Ace\r\n\t\t\treturn 1; \r\n\t\t} else {\r\n\t\t\treturn value();\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic int maxValue() {\r\n\t\tif (isAce()) { // Ace\r\n\t\t\treturn 11; \r\n\t\t} else {\r\n\t\t\treturn value();\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic boolean isAce() { \r\n\t\treturn faceValue == 1;\r\n\t} \r\n\t\r\n\tpublic boolean isFaceCard() {\r\n\t\treturn faceValue >= 11 && faceValue <= 13;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/BlackJackGameAutomator.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\nimport java.util.ArrayList;\r\n\r\npublic class BlackJackGameAutomator {\r\n\tprivate Deck deck;\r\n\tprivate BlackJackHand[] hands;\r\n\tprivate static final int HIT_UNTIL = 16;\r\n\t\r\n\tpublic BlackJackGameAutomator(int numPlayers) {\r\n\t\thands = new BlackJackHand[numPlayers];\r\n\t\tfor (int i = 0; i < numPlayers; i++) {\r\n\t\t\thands[i] = new BlackJackHand();\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic boolean dealInitial() {\r\n\t\tfor (BlackJackHand hand : hands) {\r\n\t\t\tBlackJackCard card1 = deck.dealCard();\r\n\t\t\tBlackJackCard card2 = deck.dealCard();\r\n\t\t\tif (card1 == null || card2 == null) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\thand.addCard(card1);\r\n\t\t\thand.addCard(card2);\t\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic ArrayList getBlackJacks() {\r\n\t\tArrayList winners = new ArrayList();\r\n\t\tfor (int i = 0; i < hands.length; i++) {\r\n\t\t\tif (hands[i].isBlackJack()) {\r\n\t\t\t\twinners.add(i);\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn winners;\r\n\t}\r\n\t\r\n\tpublic boolean playHand(int i) {\r\n\t\tBlackJackHand hand = hands[i];\r\n\t\treturn playHand(hand);\r\n\t}\r\n\t\r\n\tpublic boolean playHand(BlackJackHand hand) {\r\n\t\twhile (hand.score() < HIT_UNTIL) {\r\n\t\t\tBlackJackCard card = deck.dealCard();\r\n\t\t\tif (card == null) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t\thand.addCard(card);\r\n\t\t}\r\n\t\treturn true;\r\n\t}\t\r\n\t\r\n\tpublic boolean playAllHands() {\r\n\t\tfor (BlackJackHand hand : hands) {\r\n\t\t\tif (!playHand(hand)) {\r\n\t\t\t\treturn false;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic ArrayList getWinners() {\r\n\t\tArrayList winners = new ArrayList();\r\n\t\tint winningScore = 0;\r\n\t\tfor (int i = 0; i < hands.length; i++) {\r\n\t\t\tBlackJackHand hand = hands[i];\r\n\t\t\tif (!hand.busted()) {\r\n\t\t\t\tif (hand.score() > winningScore) {\r\n\t\t\t\t\twinningScore = hand.score();\r\n\t\t\t\t\twinners.clear();\r\n\t\t\t\t\twinners.add(i);\r\n\t\t\t\t} else if (hand.score() == winningScore) {\r\n\t\t\t\t\twinners.add(i);\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn winners;\r\n\t}\r\n\t\r\n\tpublic void initializeDeck() {\r\n\t\tArrayList cards = new ArrayList();\r\n\t\tfor (int i = 1; i <= 13; i++) {\r\n\t\t\tfor (int j = 0; j <= 3; j++) {\r\n\t\t\t\tSuit suit = Suit.getSuitFromValue(j);\r\n\t\t\t\tBlackJackCard card = new BlackJackCard(i, suit);\r\n\t\t\t\tcards.add(card);\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\tdeck = new Deck();\r\n\t\tdeck.setDeckOfCards(cards);\r\n\t\tdeck.shuffle();\t\r\n\t}\r\n\t\r\n\tpublic void printHandsAndScore() {\r\n\t\tfor (int i = 0; i < hands.length; i++) {\r\n\t\t\tSystem.out.print(\"Hand \" + i + \" (\" + hands[i].score() + \"): \");\r\n\t\t\thands[i].print();\r\n\t\t\tSystem.out.println(\"\");\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/BlackJackHand.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\nimport java.util.ArrayList;\r\n\r\npublic class BlackJackHand extends Hand {\r\n\tpublic BlackJackHand() {\r\n\t\t\r\n\t}\r\n\t\r\n\tpublic int score() {\r\n\t\tArrayList scores = possibleScores();\r\n\t\tint maxUnder = Integer.MIN_VALUE;\r\n\t\tint minOver = Integer.MAX_VALUE;\r\n\t\tfor (int score : scores) {\r\n\t\t\tif (score > 21 && score < minOver) {\r\n\t\t\t\tminOver = score;\r\n\t\t\t} else if (score <= 21 && score > maxUnder) {\r\n\t\t\t\tmaxUnder = score;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn maxUnder == Integer.MIN_VALUE ? minOver : maxUnder;\r\n\t}\r\n\t\r\n\tprivate ArrayList possibleScores() {\r\n\t\tArrayList scores = new ArrayList();\r\n\t\tif (cards.size() == 0) {\r\n\t\t\treturn scores;\r\n\t\t}\r\n\t\tfor (BlackJackCard card : cards) {\r\n\t\t\taddCardToScoreList(card, scores);\r\n\t\t}\r\n\t\treturn scores;\r\n\t}\r\n\t\r\n\tprivate void addCardToScoreList(BlackJackCard card, ArrayList scores) {\r\n\t\tif (scores.size() == 0) {\r\n\t\t\tscores.add(0);\r\n\t\t} \r\n\t\tint length = scores.size();\r\n\t\tfor (int i = 0; i < length; i++) {\r\n\t\t\tint score = scores.get(i);\r\n\t\t\tscores.set(i, score + card.minValue());\r\n\t\t\tif (card.minValue() != card.maxValue()) {\r\n\t\t\t\tscores.add(score + card.maxValue());\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic boolean busted() {\r\n\t\treturn score() > 21;\r\n\t}\r\n\t\r\n\tpublic boolean is21() {\r\n\t\treturn score() == 21;\r\n\t}\r\n\t\r\n\tpublic boolean isBlackJack() {\r\n\t\tif (cards.size() != 2) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tBlackJackCard first = cards.get(0);\r\n\t\tBlackJackCard second = cards.get(1);\r\n\t\treturn (first.isAce() && second.isFaceCard()) || (second.isAce() && first.isFaceCard());\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/Card.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\npublic abstract class Card {\r\n\tprivate boolean available = true;\r\n\t\r\n\t/* number or face that's on card - a number 2 through 10, \r\n\t * or 11 for Jack, 12 for Queen, 13 for King, or 1 for Ace \r\n\t */\r\n\tprotected int faceValue;\r\n\tprotected Suit suit;\r\n\r\n\tpublic Card(int c, Suit s) {\r\n\t\tfaceValue = c;\r\n\t\tsuit = s;\r\n\t}\r\n\t\r\n\tpublic abstract int value();\r\n\t\r\n\tpublic Suit suit() { \r\n\t\treturn suit; \r\n\t}\r\n\t\r\n\t/* returns whether or not the card is available to be given out to someone */\r\n\tpublic boolean isAvailable() {\r\n\t\treturn available;\r\n\t}\r\n\t\r\n\tpublic void markUnavailable() {\r\n\t\tavailable = false;\r\n\t}\r\n\t\r\n\tpublic void markAvailable() {\r\n\t\tavailable = true;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tString[] faceValues = {\"A\", \"2\", \"3\", \"4\", \"5\", \"6\", \"7\", \"8\", \"9\", \"10\", \"J\", \"Q\", \"K\"};\r\n\t\tSystem.out.print(faceValues[faceValue - 1]);\r\n\t\tswitch (suit) {\r\n\t\tcase Club:\r\n\t\t\tSystem.out.print(\"c\");\r\n\t\t\tbreak;\r\n\t\tcase Heart:\r\n\t\t\tSystem.out.print(\"h\");\r\n\t\t\tbreak;\r\n\t\tcase Diamond:\r\n\t\t\tSystem.out.print(\"d\");\r\n\t\t\tbreak;\r\n\t\tcase Spade:\r\n\t\t\tSystem.out.print(\"s\");\r\n\t\t\tbreak;\t\t\t\r\n\t\t}\r\n\t\tSystem.out.print(\" \");\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/Deck.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\nimport java.util.ArrayList;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Deck {\r\n\tprivate ArrayList cards;\r\n\tprivate int dealtIndex = 0; // marks first undealt card\r\n\t\r\n\tpublic Deck() {\r\n\t}\r\n\t\r\n\tpublic void setDeckOfCards(ArrayList deckOfCards) {\r\n\t\tcards = deckOfCards;\r\n\t}\r\n\t\r\n\tpublic void shuffle() {\r\n\t\tfor (int i = 0; i < cards.size(); i++) {\r\n\t\t\tint j = AssortedMethods.randomIntInRange(i, cards.size() - i - 1);\r\n\t\t\tT card1 = cards.get(i);\r\n\t\t\tT card2 = cards.get(j);\r\n\t\t\tcards.set(i, card2);\r\n\t\t\tcards.set(j, card1);\r\n\t\t}\r\n\t}\r\n\t\r\n\tpublic int remainingCards() {\r\n\t\treturn cards.size() - dealtIndex;\r\n\t}\r\n\t\r\n\tpublic T[] dealHand(int number) {\r\n\t\tif (remainingCards() < number) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\t\r\n\t\tT[] hand = (T[]) new Card[number];\r\n\t\tint count = 0;\r\n\t\twhile (count < number) {\r\n\t\t\tT card = dealCard();\r\n\t\t\tif (card != null) {\r\n\t\t\t\thand[count] = card;\r\n\t\t\t\tcount++;\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\treturn hand;\r\n\t}\r\n\t\r\n\tpublic T dealCard() {\r\n\t\tif (remainingCards() == 0) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\t\r\n\t\tT card = cards.get(dealtIndex);\r\n\t\tcard.markUnavailable();\r\n\t\tdealtIndex++;\r\n\t\t\r\n\t\treturn card;\t\t\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tfor (Card card : cards) {\r\n\t\t\tcard.print();\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/Hand.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\nimport java.util.ArrayList;\r\n\r\npublic class Hand {\r\n\tprotected ArrayList cards = new ArrayList();\r\n\t\r\n\tpublic int score() {\r\n\t\tint score = 0;\r\n\t\tfor (T card : cards) {\r\n\t\t\tscore += card.value();\r\n\t\t}\r\n\t\treturn score;\r\n\t}\r\n\t\r\n\tpublic void addCard(T card) {\r\n\t\tcards.add(card);\r\n\t}\t\r\n\t\r\n\tpublic void print() {\r\n\t\tfor (Card card : cards) {\r\n\t\t\tcard.print();\r\n\t\t}\r\n\t}\t\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/Question.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\nimport java.util.ArrayList;\r\n\r\npublic class Question {\r\n\r\n\t\r\n\tpublic static void main(String[] args) {\t\r\n\t\tint numHands = 5;\r\n\t\t\r\n\t\tBlackJackGameAutomator automator = new BlackJackGameAutomator(numHands);\r\n\t\tautomator.initializeDeck();\r\n\t\tboolean success = automator.dealInitial();\r\n\t\t\tif (!success) {\r\n\t\t\t\tSystem.out.println(\"Error. Out of cards.\");\r\n\t\t\t} else {\r\n\t\t\tSystem.out.println(\"-- Initial --\");\r\n\t\t\tautomator.printHandsAndScore();\r\n\t\t\tArrayList blackjacks = automator.getBlackJacks();\r\n\t\t\tif (blackjacks.size() > 0) {\r\n\t\t\t\tSystem.out.print(\"Blackjack at \");\r\n\t\t\t\tfor (int i : blackjacks) {\r\n\t\t\t\t\tSystem.out.print(i + \", \");\r\n\t\t\t\t}\r\n\t\t\t\tSystem.out.println(\"\");\r\n\t\t\t} else {\r\n\t\t\t\tsuccess = automator.playAllHands();\r\n\t\t\t\tif (!success) {\r\n\t\t\t\t\tSystem.out.println(\"Error. Out of cards.\");\r\n\t\t\t\t} else {\r\n\t\t\t\t\tSystem.out.println(\"\\n-- Completed Game --\");\r\n\t\t\t\t\tautomator.printHandsAndScore();\r\n\t\t\t\t\tArrayList winners = automator.getWinners();\r\n\t\t\t\t\tif (winners.size() > 0) {\r\n\t\t\t\t\t\tSystem.out.print(\"Winners: \");\r\n\t\t\t\t\t\tfor (int i : winners) {\r\n\t\t\t\t\t\t\tSystem.out.print(i + \", \");\r\n\t\t\t\t\t\t}\r\n\t\t\t\t\t\tSystem.out.println(\"\");\r\n\t\t\t\t\t} else {\r\n\t\t\t\t\t\tSystem.out.println(\"Draw. All players have busted.\");\r\n\t\t\t\t\t}\r\n\t\t\t\t}\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_01_Deck_of_Cards/Suit.java",
"content": "package Q7_01_Deck_of_Cards;\r\n\r\npublic enum Suit { \r\n\tClub (0),\r\n\tDiamond (1),\r\n\tHeart (2),\r\n\tSpade (3);\r\n\t\r\n\tprivate int value;\r\n\tprivate Suit(int v) {\r\n\t\tvalue = v;\r\n\t}\r\n\t\r\n\tpublic int getValue() {\r\n\t\treturn value;\r\n\t}\r\n\t\r\n\tpublic static Suit getSuitFromValue(int value) {\r\n\t\tswitch (value) {\r\n\t\tcase 0:\r\n\t\t\treturn Suit.Club;\r\n\t\tcase 1:\r\n\t\t\treturn Suit.Diamond;\r\n\t\tcase 2:\r\n\t\t\treturn Suit.Heart;\r\n\t\tcase 3: \r\n\t\t\treturn Suit.Spade;\r\n\t\tdefault:\r\n\t\t\t\treturn null;\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Call.java",
"content": "package Q7_02_Call_Center;\r\n\r\n/* Represents a call from a user. Calls have a minimum rank and are assigned to the\r\n * first employee who can handle that call.\r\n */\r\npublic class Call {\r\n\t/* Minimal rank of employee who can handle this call. */\r\n\tprivate Rank rank;\r\n\r\n\t/* Person who is calling. */\r\n\tprivate Caller caller;\r\n\r\n\t/* Employee who is handling call. */\r\n\tprivate Employee handler;\r\n\r\n\tpublic Call(Caller c) {\r\n\t\trank = Rank.Responder;\r\n\t\tcaller = c;\r\n\t}\r\n\r\n\t/* Set employee who is handling call. */\r\n\tpublic void setHandler(Employee e) {\r\n\t\thandler = e;\r\n\t}\r\n\r\n\t/* Play recorded message to the customer. */\r\n\tpublic void reply(String message) {\r\n\t\tSystem.out.println(message);\r\n\t}\r\n\r\n\tpublic Rank getRank() {\r\n\t\treturn rank;\r\n\t}\r\n\r\n\tpublic void setRank(Rank r) {\r\n\t\trank = r;\r\n\t}\r\n\r\n\tpublic Rank incrementRank() {\r\n\t\tif (rank == Rank.Responder) {\r\n\t\t\trank = Rank.Manager;\r\n\t\t} else if (rank == Rank.Manager) {\r\n\t\t\trank = Rank.Director;\r\n\t\t}\r\n\t\treturn rank;\r\n\t}\r\n\r\n\t/* Disconnect call. */\r\n\tpublic void disconnect() {\r\n\t\treply(\"Thank you for calling\");\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/CallHandler.java",
"content": "package Q7_02_Call_Center;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.List;\r\n\r\n/* CallHandler represents the body of the program,\r\n * and all calls are funneled first through it. \r\n */\r\npublic class CallHandler {\t\r\n\t/* We have 3 levels of employees: respondents, managers, directors. */\r\n private final int LEVELS = 3; \r\n \r\n /* Initialize with 10 respondents, 4 managers, and 2 directors. */\r\n private final int NUM_RESPONDENTS = 10;\r\n private final int NUM_MANAGERS = 4;\r\n private final int NUM_DIRECTORS = 2;\r\n\r\n /* List of employees, by level.\r\n * employeeLevels[0] = respondents\r\n * employeeLevels[1] = managers\r\n * employeeLevels[2] = directors\r\n */\r\n List> employeeLevels;\r\n\r\n\t/* queues for each call�s rank */\r\n List> callQueues; \r\n\r\n public CallHandler() {\r\n \temployeeLevels = new ArrayList>(LEVELS);\r\n \tcallQueues = new ArrayList>(LEVELS); \r\n \t\r\n // Create respondents.\r\n ArrayList respondents = new ArrayList(NUM_RESPONDENTS);\r\n for (int k = 0; k < NUM_RESPONDENTS - 1; k++) {\r\n respondents.add(new Respondent(this));\r\n }\r\n employeeLevels.add(respondents);\r\n\r\n // Create managers.\r\n ArrayList managers = new ArrayList(NUM_MANAGERS);\r\n managers.add(new Manager(this));\r\n employeeLevels.add(managers);\r\n\r\n // Create directors.\r\n ArrayList directors = new ArrayList(NUM_DIRECTORS);\r\n directors.add(new Director(this));\r\n employeeLevels.add(directors);\r\n }\r\n \r\n /* Gets the first available employee who can handle this call. */\r\n public Employee getHandlerForCall(Call call) {\r\n for (int level = call.getRank().getValue(); level < LEVELS - 1; level++) {\r\n List employeeLevel = employeeLevels.get(level);\r\n for (Employee emp : employeeLevel) {\r\n if (emp.isFree()) {\r\n return emp;\r\n }\r\n }\r\n }\r\n return null;\r\n }\r\n\r\n /* Routes the call to an available employee, or saves in a queue if no employee available. */\r\n public void dispatchCall(Caller caller) {\r\n \tCall call = new Call(caller);\r\n \tdispatchCall(call);\r\n }\r\n \r\n /* Routes the call to an available employee, or saves in a queue if no employee available. */\r\n public void dispatchCall(Call call) {\r\n \t/* Try to route the call to an employee with minimal rank. */\r\n Employee emp = getHandlerForCall(call);\r\n if (emp != null) {\r\n \temp.receiveCall(call);\r\n \tcall.setHandler(emp);\r\n } else {\r\n\t /* Place the call into corresponding call queue according to its rank. */\r\n\t call.reply(\"Please wait for free employee to reply\");\r\n\t callQueues.get(call.getRank().getValue()).add(call);\r\n }\r\n } \r\n\r\n /* An employee got free. Look for a waiting call that he/she can serve. Return true\r\n * if we were able to assign a call, false otherwise. */\r\n public boolean assignCall(Employee emp) {\r\n /* Check the queues, starting from the highest rank this employee can serve. */\r\n for (int rank = emp.getRank().getValue(); rank >= 0; rank--) {\r\n List que = callQueues.get(rank);\r\n \r\n /* Remove the first call, if any */\r\n if (que.size() > 0) {\r\n\t Call call = que.remove(0); \r\n\t if (call != null) {\r\n\t emp.receiveCall(call);\r\n\t return true;\r\n\t }\r\n }\r\n }\r\n return false;\r\n }\r\n}\r\n\r\n\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Caller.java",
"content": "package Q7_02_Call_Center;\r\n\r\npublic class Caller {\r\n\tprivate String name;\r\n\tprivate int userId;\r\n\tpublic Caller(int id, String nm) {\r\n\t\tname = nm;\r\n\t\tuserId = id;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Director.java",
"content": "package Q7_02_Call_Center;\r\n\r\nclass Director extends Employee {\r\n public Director(CallHandler callHandler) {\r\n \tsuper(callHandler);\r\n \trank = Rank.Director;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Employee.java",
"content": "package Q7_02_Call_Center;\r\n\r\n/* Employee is a super class for the Director, Manager, and Respondent classes. It is implemented as an\r\n * abstract class, since there should be no reason to instantiated an Employee type directly.\r\n */\r\nabstract class Employee {\r\n\tprivate Call currentCall = null;\r\n\tprotected Rank rank;\r\n\tprivate CallHandler callHandler;\r\n\r\n\tpublic Employee(CallHandler handler) {\r\n\t\tcallHandler = handler;\r\n\t}\r\n\r\n\t/* Start the conversation */\r\n\tpublic void receiveCall(Call call) {\r\n\t\tcurrentCall = call;\r\n\t}\r\n\r\n\t/* the issue is resolved, finish the call */\r\n\tpublic void callCompleted() {\r\n\t\tif (currentCall != null) {\r\n\t\t\t/* Disconnect the call. */\r\n\t\t\tcurrentCall.disconnect();\r\n\r\n\t\t\t/* Free the employee */\r\n\t\t\tcurrentCall = null;\r\n\t\t}\r\n\r\n\t\t/* Check if there is a call waiting in queue */\r\n\t\tassignNewCall();\r\n\t}\r\n\r\n\t/*\r\n\t * The issue has not been resolved. Escalate the call, and assign a new call\r\n\t * to the employee.\r\n\t */\r\n\tpublic void escalateAndReassign() {\r\n\t\tif (currentCall != null) {\r\n\t\t\t/* escalate call */\r\n\t\t\tcurrentCall.incrementRank();\r\n\t\t\tcallHandler.dispatchCall(currentCall);\r\n\r\n\t\t\t/* free the employee */\r\n\t\t\tcurrentCall = null;\r\n\t\t}\r\n\r\n\t\t/* assign a new call */\r\n\t\tassignNewCall();\r\n\t}\r\n\r\n\t/* Assign a new call to an employee, if the employee is free. */\r\n\tpublic boolean assignNewCall() {\r\n\t\tif (!isFree()) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn callHandler.assignCall(this);\r\n\t}\r\n\r\n\t/* Returns whether or not the employee is free. */\r\n\tpublic boolean isFree() {\r\n\t\treturn currentCall == null;\r\n\t}\r\n\r\n\tpublic Rank getRank() {\r\n\t\treturn rank;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Manager.java",
"content": "package Q7_02_Call_Center;\r\n\r\nclass Manager extends Employee {\r\n public Manager(CallHandler callHandler) {\r\n \tsuper(callHandler);\r\n \trank = Rank.Manager;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Rank.java",
"content": "package Q7_02_Call_Center;\r\n\r\npublic enum Rank {\r\n\tResponder (0),\r\n\tManager (1),\r\n\tDirector (2);\r\n\t\r\n\tprivate int value;\r\n\t\r\n\tprivate Rank(int v) {\r\n\t\tvalue = v;\r\n\t}\r\n\t\r\n\tpublic int getValue() {\r\n\t\treturn value;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Respondent.java",
"content": "package Q7_02_Call_Center;\r\n\r\nclass Respondent extends Employee {\r\n public Respondent(CallHandler callHandler) {\r\n \tsuper(callHandler);\r\n \trank = Rank.Responder;\r\n }\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_02_Call_Center/Test.java",
"content": "package Q7_02_Call_Center;\r\n\r\npublic class Test {\r\n\r\n\t/**\r\n\t * @param args\r\n\t */\r\n\tpublic static void main(String[] args) {\r\n\t\tCallHandler ch = new CallHandler();\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/CD.java",
"content": "package Q7_03_Jukebox;\r\n\r\npublic class CD {\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/CDPlayer.java",
"content": "package Q7_03_Jukebox;\r\n\r\npublic class CDPlayer {\r\n\tprivate Playlist p;\r\n\tprivate CD c;\r\n\t\r\n\tpublic Playlist getPlaylist() { return p; }\r\n\tpublic void setPlaylist(Playlist p) { this.p = p; }\r\n\tpublic CD getCD() { return c; }\r\n\tpublic void setCD(CD c) { this.c = c; }\r\n\t\r\n\tpublic CDPlayer(Playlist p) { this.p = p; }\r\n\tpublic CDPlayer(CD c, Playlist p) { \r\n\t\tthis.p = p;\r\n\t\tthis.c = c;\r\n\t}\r\n\r\n\tpublic CDPlayer(CD c){ this.c = c; }\r\n\tpublic void playSong(Song s) { }\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/JukeBox.java",
"content": "package Q7_03_Jukebox;\r\n\r\nimport java.util.Set;\r\n\r\npublic class JukeBox {\r\n\tprivate CDPlayer cdPlayer;\r\n\tprivate User user;\r\n\tprivate Set cdCollection;\r\n\tprivate SongSelector ts;\r\n\t\r\n\tpublic JukeBox(CDPlayer cdPlayer, User user, Set cdCollection,\r\n\t\t\t\t SongSelector ts) {\r\n\t\tsuper();\r\n\t\tthis.cdPlayer = cdPlayer;\r\n\t\tthis.user = user;\r\n\t\tthis.cdCollection = cdCollection;\r\n\t\tthis.ts = ts;\r\n\t}\r\n\t\r\n\tpublic Song getCurrentSong() { return ts.getCurrentSong();\t}\r\n\tpublic void setUser(User u) { this.user = u;\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/Playlist.java",
"content": "package Q7_03_Jukebox;\r\n\r\nimport java.util.Queue;\r\n\r\npublic class Playlist {\r\n\tprivate Song song;\r\n\tprivate Queue queue;\r\n\tpublic Playlist(Song song, Queue queue) {\r\n\t\tsuper();\r\n\t\tthis.song = song;\r\n\t\tthis.queue = queue;\r\n\t}\r\n\t\r\n\tpublic Song getNextSongToPlay(){ return queue.peek(); }\r\n\tpublic void queueUpSong(Song s){ queue.add(s); }\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/Song.java",
"content": "package Q7_03_Jukebox;\r\n\r\npublic class Song {\r\n\tprivate String songName;\r\n\tpublic String toString() { return songName; }\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/SongSelector.java",
"content": "package Q7_03_Jukebox;\r\n\r\n\r\npublic class SongSelector {\r\n\tprivate Song currentSong;\r\n\tpublic SongSelector(Song s) { currentSong=s; }\r\n\tpublic void setSong(Song s) { currentSong = s;\t}\r\n\tpublic Song getCurrentSong() { return currentSong;\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_03_Jukebox/User.java",
"content": "package Q7_03_Jukebox;\r\n\r\npublic class User {\r\n\tprivate String name;\r\n\tpublic String getName() { return name; }\r\n\tpublic void setName(String name) {\tthis.name = name; }\r\n\tpublic long getID() { return ID; }\r\n\tpublic void setID(long iD) { ID = iD; }\r\n\tprivate long ID;\r\n\tpublic User(String name, long iD) {\r\n\t\tthis.name = name;\r\n\t\tID = iD;\r\n\t}\r\n\tpublic User getUser() { return this; }\r\n\tpublic static User addUser(String name, long iD){\r\n\t\treturn new User(name, iD);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Bus.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic class Bus extends Vehicle {\r\n\tpublic Bus() {\r\n\t\tspotsNeeded = 5;\r\n\t\tsize = VehicleSize.Large;\r\n\t}\r\n\t\r\n\tpublic boolean canFitInSpot(ParkingSpot spot) {\r\n\t\treturn spot.getSize() == VehicleSize.Large;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tSystem.out.print(\"B\");\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Car.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic class Car extends Vehicle {\r\n\tpublic Car() {\r\n\t\tspotsNeeded = 1;\r\n\t\tsize = VehicleSize.Compact;\r\n\t}\r\n\t\r\n\tpublic boolean canFitInSpot(ParkingSpot spot) {\r\n\t\treturn spot.getSize() == VehicleSize.Large || spot.getSize() == VehicleSize.Compact;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tSystem.out.print(\"C\");\r\n\t}\t\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Level.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\n/* Represents a level in a parking garage */\r\npublic class Level {\r\n\tprivate int floor;\r\n\tprivate ParkingSpot[] spots;\r\n\tprivate int availableSpots = 0; // number of free spots\r\n\tprivate static final int SPOTS_PER_ROW = 10;\r\n\t\r\n\tpublic Level(int flr, int numberSpots) {\r\n\t\tfloor = flr;\r\n\t\tspots = new ParkingSpot[numberSpots];\r\n\t\tint largeSpots = numberSpots / 4;\r\n\t\tint bikeSpots = numberSpots / 4;\r\n\t\tint compactSpots = numberSpots - largeSpots - bikeSpots;\r\n\t\tfor (int i = 0; i < numberSpots; i++) {\r\n\t\t\tVehicleSize sz = VehicleSize.Motorcycle;\r\n\t\t\tif (i < largeSpots) {\r\n\t\t\t\tsz = VehicleSize.Large;\r\n\t\t\t} else if (i < largeSpots + compactSpots) {\r\n\t\t\t\tsz = VehicleSize.Compact;\r\n\t\t\t}\r\n\t\t\tint row = i / SPOTS_PER_ROW;\r\n\t\t\tspots[i] = new ParkingSpot(this, row, i, sz);\r\n\t\t}\r\n\t\tavailableSpots = numberSpots;\r\n\t}\r\n\t\r\n\tpublic int availableSpots() {\r\n\t\treturn availableSpots;\r\n\t}\r\n\t\r\n\t/* Try to find a place to park this vehicle. Return false if failed. */\r\n\tpublic boolean parkVehicle(Vehicle vehicle) {\r\n\t\tif (availableSpots() < vehicle.getSpotsNeeded()) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tint spotNumber = findAvailableSpots(vehicle);\r\n\t\tif (spotNumber < 0) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\treturn parkStartingAtSpot(spotNumber, vehicle);\r\n\t}\r\n\t\r\n\t/* Park a vehicle starting at the spot spotNumber, and continuing until vehicle.spotsNeeded. */\r\n\tprivate boolean parkStartingAtSpot(int spotNumber, Vehicle vehicle) {\r\n\t\tvehicle.clearSpots();\r\n\t\tboolean success = true;\r\n\t\tfor (int i = spotNumber; i < spotNumber + vehicle.spotsNeeded; i++) {\r\n\t\t\t success &= spots[i].park(vehicle);\r\n\t\t}\r\n\t\tavailableSpots -= vehicle.spotsNeeded;\r\n\t\treturn success;\r\n\t}\r\n\t\r\n\t/* find a spot to park this vehicle. Return index of spot, or -1 on failure. */\r\n\tprivate int findAvailableSpots(Vehicle vehicle) {\r\n\t\tint spotsNeeded = vehicle.getSpotsNeeded();\r\n\t\tint lastRow = -1;\r\n\t\tint spotsFound = 0;\r\n\t\tfor (int i = 0; i < spots.length; i++) {\r\n\t\t\tParkingSpot spot = spots[i];\r\n\t\t\tif (lastRow != spot.getRow()) {\r\n\t\t\t\tspotsFound = 0;\r\n\t\t\t\tlastRow = spot.getRow();\r\n\t\t\t}\r\n\t\t\tif (spot.canFitVehicle(vehicle)) {\r\n\t\t\t\tspotsFound++;\r\n\t\t\t} else {\r\n\t\t\t\tspotsFound = 0;\r\n\t\t\t}\r\n\t\t\tif (spotsFound == spotsNeeded) {\r\n\t\t\t\treturn i - (spotsNeeded - 1);\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn -1;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tint lastRow = -1;\r\n\t\tfor (int i = 0; i < spots.length; i++) {\r\n\t\t\tParkingSpot spot = spots[i];\r\n\t\t\tif (spot.getRow() != lastRow) {\r\n\t\t\t\tSystem.out.print(\" \");\r\n\t\t\t\tlastRow = spot.getRow();\r\n\t\t\t}\r\n\t\t\tspot.print();\r\n\t\t}\r\n\t}\r\n\t\r\n\t/* When a car was removed from the spot, increment availableSpots */\r\n\tpublic void spotFreed() {\r\n\t\tavailableSpots++;\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Motorcycle.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic class Motorcycle extends Vehicle {\r\n\tpublic Motorcycle() {\r\n\t\tspotsNeeded = 1;\r\n\t\tsize = VehicleSize.Motorcycle;\r\n\t}\r\n\t\r\n\tpublic boolean canFitInSpot(ParkingSpot spot) {\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tSystem.out.print(\"M\");\r\n\t}\t\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/ParkingLot.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic class ParkingLot {\r\n\tprivate Level[] levels;\r\n\tprivate final int NUM_LEVELS = 5;\r\n\t\r\n\tpublic ParkingLot() {\r\n\t\tlevels = new Level[NUM_LEVELS];\r\n\t\tfor (int i = 0; i < NUM_LEVELS; i++) {\r\n\t\t\tlevels[i] = new Level(i, 30);\r\n\t\t}\r\n\t}\r\n\t\r\n\t/* Park the vehicle in a spot (or multiple spots). Return false if failed. */\r\n\tpublic boolean parkVehicle(Vehicle vehicle) {\r\n\t\tfor (int i = 0; i < levels.length; i++) {\r\n\t\t\tif (levels[i].parkVehicle(vehicle)) {\r\n\t\t\t\treturn true;\r\n\t\t\t}\r\n\t\t}\r\n\t\treturn false;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tfor (int i = 0; i < levels.length; i++) {\r\n\t\t\tSystem.out.print(\"Level\" + i + \": \");\r\n\t\t\tlevels[i].print();\r\n\t\t\tSystem.out.println(\"\");\r\n\t\t}\r\n\t\tSystem.out.println(\"\");\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/ParkingSpot.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic class ParkingSpot {\r\n\tprivate Vehicle vehicle;\r\n\tprivate VehicleSize spotSize;\r\n\tprivate int row;\r\n\tprivate int spotNumber;\r\n\tprivate Level level;\r\n\t\r\n\tpublic ParkingSpot(Level lvl, int r, int n, VehicleSize sz) {\r\n\t\tlevel = lvl;\r\n\t\trow = r;\r\n\t\tspotNumber = n;\r\n\t\tspotSize = sz;\r\n\t}\r\n\t\r\n\tpublic boolean isAvailable() {\r\n\t\treturn vehicle == null;\r\n\t}\r\n\t\r\n\t/* Checks if the spot is big enough for the vehicle (and is available). This compares\r\n\t * the SIZE only. It does not check if it has enough spots. */\r\n\tpublic boolean canFitVehicle(Vehicle vehicle) {\r\n\t\treturn isAvailable() && vehicle.canFitInSpot(this);\r\n\t}\r\n\t\r\n\t/* Park vehicle in this spot. */\r\n\tpublic boolean park(Vehicle v) {\r\n\t\tif (!canFitVehicle(v)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tvehicle = v;\r\n\t\tvehicle.parkInSpot(this);\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic int getRow() {\r\n\t\treturn row;\r\n\t}\r\n\t\r\n\tpublic int getSpotNumber() {\r\n\t\treturn spotNumber;\r\n\t}\r\n\t\r\n\tpublic VehicleSize getSize() {\r\n\t\treturn spotSize;\r\n\t}\r\n\t\r\n\t/* Remove vehicle from spot, and notify level that a new spot is available */\r\n\tpublic void removeVehicle() {\r\n\t\tlevel.spotFreed();\r\n\t\tvehicle = null;\r\n\t}\r\n\t\r\n\tpublic void print() {\r\n\t\tif (vehicle == null) {\r\n\t\t\tif (spotSize == VehicleSize.Compact) {\r\n\t\t\t\tSystem.out.print(\"c\");\r\n\t\t\t} else if (spotSize == VehicleSize.Large) {\r\n\t\t\t\tSystem.out.print(\"l\");\r\n\t\t\t} else if (spotSize == VehicleSize.Motorcycle) {\r\n\t\t\t\tSystem.out.print(\"m\");\r\n\t\t\t}\r\n\t\t} else {\r\n\t\t\tvehicle.print();\r\n\t\t}\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Question.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\nimport CtCILibrary.AssortedMethods;\r\n\r\npublic class Question {\r\n\r\n\t/**\r\n\t * @param args\r\n\t */\r\n\tpublic static void main(String[] args) {\r\n\t\tParkingLot lot = new ParkingLot();\r\n\t\t\r\n\t\tVehicle v = null;\r\n\t\twhile (v == null || lot.parkVehicle(v)) {\r\n\t\t\tlot.print();\r\n\t\t\tint r = AssortedMethods.randomIntInRange(0, 10);\r\n\t\t\tif (r < 2) {\r\n\t\t\t\tv = new Bus();\r\n\t\t\t} else if (r < 4) {\r\n\t\t\t\tv = new Motorcycle();\r\n\t\t\t} else {\r\n\t\t\t\tv = new Car();\r\n\t\t\t}\r\n\t\t\tSystem.out.print(\"\\nParking a \");\r\n\t\t\tv.print();\r\n\t\t\tSystem.out.println(\"\");\r\n\t\t}\r\n\t\tSystem.out.println(\"Parking Failed. Final state: \");\r\n\t\tlot.print();\r\n\t}\r\n\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/Vehicle.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\nimport java.util.ArrayList;\r\n\r\npublic abstract class Vehicle {\r\n\tprotected ArrayList parkingSpots = new ArrayList();\r\n\tprotected String licensePlate;\r\n\tprotected int spotsNeeded;\r\n\tprotected VehicleSize size;\r\n\t\r\n\tpublic int getSpotsNeeded() {\r\n\t\treturn spotsNeeded;\r\n\t}\r\n\t\r\n\tpublic VehicleSize getSize() {\r\n\t\treturn size;\r\n\t}\r\n\r\n\t/* Park vehicle in this spot (among others, potentially) */\r\n\tpublic void parkInSpot(ParkingSpot spot) {\r\n\t\tparkingSpots.add(spot);\r\n\t}\r\n\t\r\n\t/* Remove car from spot, and notify spot that it's gone */\r\n\tpublic void clearSpots() {\r\n\t\tfor (int i = 0; i < parkingSpots.size(); i++) {\r\n\t\t\tparkingSpots.get(i).removeVehicle();\r\n\t\t}\r\n\t\tparkingSpots.clear();\r\n\t}\r\n\t\r\n\tpublic abstract boolean canFitInSpot(ParkingSpot spot);\r\n\tpublic abstract void print();\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_04_Parking_Lot/VehicleSize.java",
"content": "package Q7_04_Parking_Lot;\r\n\r\npublic enum VehicleSize {\r\n\tMotorcycle, \r\n\tCompact, \r\n\tLarge,\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/Book.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\npublic class Book {\r\n\tprivate int bookId;\r\n\tprivate String details;\t\r\n\t\r\n\tpublic Book(int id, String det) {\r\n\t\tbookId = id;\r\n\t\tdetails = det;\r\n\t}\r\n\t\r\n\tpublic void update() { } \r\n\t\r\n\tpublic int getID() { \r\n\t\treturn bookId; \r\n\t}\r\n\t\r\n\tpublic void setID(int id) { \r\n\t\tbookId = id;\r\n\t}\r\n\t\r\n\tpublic String getDetails() { \r\n\t\treturn details;\r\n\t}\r\n\t\r\n\tpublic void setDetails(String details) { \r\n\t\tthis.details = details; \r\n\t}\r\n}"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/Display.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\npublic class Display {\r\n\tprivate Book activeBook;\r\n\tprivate User activeUser;\r\n\tprivate int pageNumber = 0;\r\n\t\r\n\tpublic void displayUser(User user) {\r\n\t\tactiveUser = user;\r\n\t\trefreshUsername();\r\n\t}\r\n\t\r\n\tpublic void displayBook(Book book) {\r\n\t\tpageNumber = 0;\r\n\t\tactiveBook = book;\r\n\t\t\r\n\t\trefreshTitle();\r\n\t\trefreshDetails();\r\n\t\trefreshPage();\r\n\t}\r\n\t\r\n\tpublic void refreshUsername() {\r\n\t\t/* updates username display */\r\n\t}\r\n\t\r\n\tpublic void refreshTitle() {\r\n\t\t/* updates title display */\r\n\t}\r\n\t\r\n\tpublic void refreshDetails() {\r\n\t\t/* updates details display */\r\n\t}\r\n\t\r\n\tpublic void refreshPage() {\r\n\t\t/* updated page display */\r\n\t}\r\n\t\r\n\tpublic void turnPageForward() {\r\n\t\tpageNumber++;\r\n\t\trefreshPage();\r\n\t}\r\n\t\r\n\tpublic void turnPageBackward() {\r\n\t\tpageNumber--;\r\n\t\trefreshPage();\r\n\t}\t\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/Library.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\nimport java.util.HashMap;\r\n\r\npublic class Library {\r\n\r\n\tprivate HashMap books;\r\n\t\r\n\tpublic Book addBook(int id, String details) {\r\n\t\tif (books.containsKey(id)) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\tBook book = new Book(id, details);\r\n\t\tbooks.put(id, book);\r\n\t\treturn book;\r\n\t}\r\n\t\r\n\tpublic boolean remove(Book b){\r\n\t\treturn remove(b.getID());\r\n\t}\r\n\t\r\n\tpublic boolean remove(int id) {\r\n\t\tif (!books.containsKey(id)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tbooks.remove(id);\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic Book find(int id){\r\n\t\treturn books.get(id);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/OnlineReaderSystem.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\npublic class OnlineReaderSystem {\r\n\tprivate Library library;\r\n\tprivate UserManager userManager;\r\n\tprivate Display display;\r\n\t\r\n\tprivate Book activeBook;\r\n\tprivate User activeUser;\r\n\t\r\n\tpublic OnlineReaderSystem() {\r\n\t\tuserManager = new UserManager();\r\n\t\tlibrary = new Library();\r\n\t\tdisplay = new Display();\r\n\t}\r\n\t\r\n\tpublic Library getLibrary() {\r\n\t\treturn library;\r\n\t}\r\n\t\r\n\tpublic UserManager getUserManager() {\r\n\t\treturn userManager;\r\n\t}\r\n\t\r\n\tpublic Display getDisplay() {\r\n\t\treturn display;\r\n\t}\r\n\t\r\n\tpublic Book getActiveBook() {\r\n\t\treturn activeBook;\r\n\t}\r\n\t\r\n\tpublic void setActiveBook(Book book) {\r\n\t\tdisplay.displayBook(book);\r\n\t\tactiveBook = book;\r\n\t}\r\n\t\r\n\tpublic User getActiveUser() {\r\n\t\treturn activeUser;\r\n\t}\r\n\t\r\n\tpublic void setActiveUser(User user) {\r\n\t\tactiveUser = user;\r\n\t\tdisplay.displayUser(user);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/User.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\npublic class User {\r\n\tprivate int userId;\r\n\tprivate String details;\r\n\tprivate int accountType;\r\n\t\r\n\tpublic void renewMembership() { }\r\n\r\n\tpublic User(int id, String details, int accountType) {\r\n\t\tuserId = id;\r\n\t\tthis.details = details;\r\n\t\tthis.accountType = accountType;\r\n\t}\r\n\t\r\n\t/* getters and setters */\r\n\tpublic int getID() { return userId; }\r\n\tpublic void setID(int id) { userId = id; }\r\n\tpublic String getDetails() { return details; }\r\n\tpublic void setDetails(String details) { this.details = details; }\r\n\tpublic int getAccountType() { return accountType; }\r\n\tpublic void setAccountType(int accountType) { \r\n\t\tthis.accountType = accountType;\r\n\t}\r\n}\r\n\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_05_Online_Book_Reader/UserManager.java",
"content": "package Q7_05_Online_Book_Reader;\r\n\r\nimport java.util.HashMap;\r\n\r\npublic class UserManager {\r\n\tprivate HashMap users;\r\n\t\r\n\tpublic User addUser(int id, String details, int accountType) {\r\n\t\tif (users.containsKey(id)) {\r\n\t\t\treturn null;\r\n\t\t}\r\n\t\tUser user = new User(id, details, accountType);\r\n\t\tusers.put(id, user);\r\n\t\treturn user;\r\n\t}\r\n\t\r\n\tpublic boolean remove(User u) {\r\n\t\treturn remove(u.getID());\r\n\t}\r\n\t\r\n\tpublic boolean remove(int id) {\r\n\t\tif (!users.containsKey(id)) {\r\n\t\t\treturn false;\r\n\t\t}\r\n\t\tusers.remove(id);\r\n\t\treturn true;\r\n\t}\r\n\t\r\n\tpublic User find(int id){\r\n\t\treturn users.get(id);\r\n\t}\r\n}\r\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_06_Jigsaw/Edge.java",
"content": "package Q7_06_Jigsaw;\n\npublic class Edge {\t\n\tprivate Shape shape;\n\tprivate String code; // used to mock how pieces would fit together.\n\tprivate Piece parentPiece;\n\t\n\tpublic Edge(Shape shape, String code) {\n\t\tthis.shape = shape;\n\t\tthis.code = code;\n\t}\n\t\n\tprivate String getCode() {\n\t\treturn code;\n\t}\n\t\n\tpublic Edge _createMatchingEdge() {\n\t\tif (shape == Shape.FLAT) return null;\n\t\treturn new Edge(shape.getOpposite(), getCode());\n\t}\n\n\t/* Check if this edge fits into the other one. */\n\tpublic boolean fitsWith(Edge edge) { \n\t\treturn edge.getCode().equals(getCode());\n\t}\n\t\n\t/* Set parent piece. */\n\tpublic void setParentPiece(Piece parentPiece) {\n\t\tthis.parentPiece = parentPiece;\n\t}\n\t\n\t/* Get the parent piece. */\n\tpublic Piece getParentPiece() {\n\t\treturn parentPiece;\n\t}\n\t\n\t/* Return the shape of the edge. */\n\tpublic Shape getShape() {\n\t\treturn shape;\n\t}\n\t\n\tpublic String toString() {\n\t\treturn code;\n\t}\n}\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_06_Jigsaw/Orientation.java",
"content": "package Q7_06_Jigsaw;\n\npublic enum Orientation {\n\tLEFT, TOP, RIGHT, BOTTOM; // Should stay in this order \n\t\n\tpublic Orientation getOpposite() {\n\t\tswitch (this) {\n\t\t\tcase LEFT: return RIGHT;\n\t\t\tcase RIGHT: return LEFT;\n\t\t\tcase TOP: return BOTTOM;\n\t\t\tcase BOTTOM: return TOP;\n\t\t\tdefault: return null;\n\t\t}\n\t}\n}\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_06_Jigsaw/Piece.java",
"content": "package Q7_06_Jigsaw;\n\nimport java.util.HashMap;\nimport java.util.Map.Entry;\n\npublic class Piece {\n\tprivate final static int NUMBER_OF_EDGES = 4;\n\tprivate HashMap edges = new HashMap();\n\t\n\tpublic Piece(Edge[] edgeList) {\t\t\n\t\tOrientation[] orientations = Orientation.values();\n\t\tfor (int i = 0; i < edgeList.length; i++) {\n\t\t\tEdge edge = edgeList[i];\n\t\t\tedge.setParentPiece(this);\t\n\t\t\tedges.put(orientations[i], edge);\n\t\t}\n\t}\n\t\n\t/* Set this edge in the appropriate orientation, rotating the piece as necessary. */\n\tpublic void setEdgeAsOrientation(Edge edge, Orientation orientation) {\n\t\tOrientation currentOrientation = getOrientation(edge);\n\t\trotateEdgesBy(orientation.ordinal() - currentOrientation.ordinal());\n\t}\n\t\n\t/* Return the current orientation of the edge. */\n\tprivate Orientation getOrientation(Edge edge) {\n\t\tfor (Entry entry : edges.entrySet()) {\n\t\t\tif (entry.getValue() == edge) {\n\t\t\t\treturn entry.getKey();\n\t\t\t}\n\t\t}\n\t\treturn null;\n\t}\n\t\n\t/* Rotate edges by \"numberRotations\". */\n\tpublic void rotateEdgesBy(int numberRotations) {\n\t\tOrientation[] orientations = Orientation.values();\n\t\tHashMap rotated = new HashMap();\n\t\t\n\t\tnumberRotations = numberRotations % NUMBER_OF_EDGES;\n\t\tif (numberRotations < 0) numberRotations += NUMBER_OF_EDGES;\n\t\t\n\t\tfor (int i = 0; i < orientations.length; i++) {\n\t\t\tOrientation oldOrientation = orientations[(i - numberRotations + NUMBER_OF_EDGES) % NUMBER_OF_EDGES];\n\t\t\tOrientation newOrientation = orientations[i];\n\t\t\trotated.put(newOrientation, edges.get(oldOrientation));\n\t\t}\t\t\n\t\tedges = rotated;\n\t}\n\t\n\t/* Check if this piece is a corner piece. */\n\tpublic boolean isCorner() {\n\t\tOrientation[] orientations = Orientation.values();\n\t\tfor (int i = 0; i < orientations.length; i++) {\n\t\t\tShape current = edges.get(orientations[i]).getShape();\n\t\t\tShape next = edges.get(orientations[(i + 1) % NUMBER_OF_EDGES]).getShape();\n\t\t\tif (current == Shape.FLAT && next == Shape.FLAT) {\n\t\t\t\treturn true;\n\t\t\t}\n\t\t}\n\t\treturn false;\n\t}\n\t\n\t/* Check if this piece has a border edge. */\n\tpublic boolean isBorder() {\n\t\tOrientation[] orientations = Orientation.values();\n\t\tfor (int i = 0; i < orientations.length; i++) {\n\t\t\tif (edges.get(orientations[i]).getShape() == Shape.FLAT) {\n\t\t\t\treturn true;\n\t\t\t}\n\t\t}\n\t\treturn false;\n\t}\n\t\n\t/* Get edge at this orientation. */\n\tpublic Edge getEdgeWithOrientation(Orientation orientation) {\n\t\treturn edges.get(orientation);\n\t}\t\n\t\n\t/* Return the edge that matches targetEdge. Returns null if there is no match. */\n\tpublic Edge getMatchingEdge(Edge targetEdge) {\n\t\tfor (Edge e : edges.values()) {\n\t\t\tif (targetEdge.fitsWith(e)) {\n\t\t\t\treturn e;\n\t\t\t}\n\t\t}\n\t\treturn null;\n\t}\n\t\n\tpublic String toString() {\n\t\tStringBuilder sb = new StringBuilder();\n\t\tOrientation[] orientations = Orientation.values();\n\t\tfor (Orientation o : orientations) {\n\t\t\tsb.append(edges.get(o).toString() + \",\");\n\t\t}\n\t\treturn \"[\" + sb.toString() + \"]\";\n\t}\n}\n"
},
{
"path": "Java/Ch 07. Object-Oriented Design/Q7_06_Jigsaw/Puzzle.java",
"content": "package Q7_06_Jigsaw;\n\nimport java.util.LinkedList;\n\npublic class Puzzle {\n\tprivate LinkedList pieces; /* Remaining pieces left to put away. */ \n\tprivate Piece[][] solution;\n\tprivate int size;\n\t\n\tpublic Puzzle(int size, LinkedList pieces) {\n\t\tthis.pieces = pieces;\n\t\tthis.size = size;\n\t}\n\t\n\t/* Group pieces into border pieces (including corners) and inside pieces. */\n\tpublic void groupPieces(LinkedList cornerPieces, LinkedList borderPieces, LinkedList insidePieces) {\n\t\tfor (Piece p : pieces) {\n\t\t\tif (p.isCorner()) {\n\t\t\t\tcornerPieces.add(p);\n\t\t\t} else if (p.isBorder()) {\n\t\t\t\tborderPieces.add(p);\n\t\t\t} else {\n\t\t\t\tinsidePieces.add(p);\n\t\t\t}\n\t\t}\n\t}\n\t\n\t/* Orient this corner piece so that its flat edges are on the top and left. */ \n\tpublic void orientTopLeftCorner(Piece piece) {\n\t\tif (!piece.isCorner()) return;\n\t\t\n\t\tOrientation[] orientations = Orientation.values();\n\t\tfor (int i = 0; i < orientations.length; i++) {\n\t\t\tEdge current = piece.getEdgeWithOrientation(orientations[i]);\n\t\t\tEdge next = piece.getEdgeWithOrientation(orientations[(i + 1) % orientations.length]);\n\t\t\tif (current.getShape() == Shape.FLAT && next.getShape() == Shape.FLAT) {\n\t\t\t\tpiece.setEdgeAsOrientation(current, Orientation.LEFT);\n\t\t\t\treturn;\n\t\t\t}\t\n\t\t}\n\t}\n\t\n\t/* Bounds check. Check if this index is on a border (0 or size - 1) */\n\tpublic boolean isBorderIndex(int location) {\n\t\treturn location == 0 || location == size - 1;\n\t}\n\t\n\t/* Given a list of pieces, check if any have an edge that matches this piece. Return the edge*/\n\tprivate Edge getMatchingEdge(Edge targetEdge, LinkedList pieces) {\n\t\tfor (Piece piece : pieces) {\n\t\t\tEdge matchingEdge = piece.getMatchingEdge(targetEdge);\n\t\t\tif (matchingEdge != null) {\n\t\t\t\treturn matchingEdge;\n\t\t\t}\n\t\t}\t\n\t\treturn null;\n\t}\n\t\n\t/* Put the edge/piece into the solution, turn it appropriately, and remove from list. */ \n\tprivate void setEdgeInSolution(LinkedList pieces, Edge edge, int row, int column, Orientation orientation) {\n\t\tPiece piece = edge.getParentPiece();\n\t\tpiece.setEdgeAsOrientation(edge, orientation);\n\t\tpieces.remove(piece);\n\t\tsolution[row][column] = piece;\n\t}\n\t\n\t/* Return the list where a piece with this index would be found. */\n\tprivate LinkedList getPieceListToSearch(LinkedList cornerPieces, LinkedList