You are welcome to use code. If you find any bug, please file an issue. I will fix it soon. I will continue publishing new code whenever I see any interesting coding puzzle.

[Puzzle Coding] (https://github.com/xiaoningning/algorithm/tree/master/PuzzleCoding) It includes a collection of fun coding puzzles.

• AddBinary: add two binary number from string
• AddTwoNumber: add two number from arrays
• BSTtoDLL: convert binary search tree to double linked list
• BTreeIterator: binary tree iterator: in-order, pre-order, post-order
• BuildBT: build binary from array inputs
• ClimbStairs: climb stair problem
• CombinationPermutation: combination and permutation problems
• CombinationSum: the sum of combination in array
• CompareArrayBST: compare binary search tree
• DecodeNumber: how many ways to decode number
• FindMiddleShiftedSorted: find the middle elements of shifted sorted array
• GenerateParentheses: generate parentheses and valid parentheses string
• GrayCode: gray code
• HanoiTower: Hanoi tower game
• InsertCyclicList: insert element into a cyclic list
• IntervalComparator: merge interval comparator class
• IntToString: convert integer into A, B, C,.. AA, AB...
• IsBST: validate binary search tree
• IsBSTPostOrder: check if an array is a post-order bst.
• JumpGame: Jump Game
• LargestBSTSubtree: largest BST which may or may not include all children
• LongestBalanceSubstring: longest balanced substring
• LongestPalindrome: a linear way to find a longest palindrome string
• LongestStringWithoutRepeat: longest string without repeat
• MaxInWindow: max value in a sliding window
• MergeIntervals: merge intervals
• MergeSortedArray: k-way merge sorted arrays, using min heap
• MinCostSortedArray: cost to sort array
• MinCuttingWords: the minimal way to cut string based on dictionary
• MinHeap: min heap implementation
• MinPathSum: min sum of path (DP and Dijkstra)
• MinWindowSubString: minimal window of substring
• Node: tree node
• Queen: Queen game
• QueueByStack: implement queue with stack
• Rand: Random number, rejecting sampling
• RegexMatch: regex string match
• ScrambleString: scramble string puzzle
• SearchInRotatedSortedArray: search in rotated sorted array
• SecondLargeInt: the second large int in array
• SetMatrixZero: set matrix to zero (in-place)
• SimplifyUnixPath: simply unix directory path
• SpiralMatrix: generate spiral matrix
• StablePartition: in-place partition array
• StringAnagram: anagram string
• ThreeSumClosest: three sum closest to a num in array
• TreeLeafPath: tree leaf path print
• Trie: trie implementation
• ValidSudoku: valid Sudoku game
• WordEditDistance: calculate the distance of word
• ZigZagPrintMatrix: zigzag print matrix

• ActivityZero
• allSubsets
• BlockingQueue
• boggleWords
• boldTree
• BTree
• coin
• DataCenterCooling
• find2DArray
• FindLargestSubMatrix
• IntArrayOps
• isNumber
• longPalindromicString
• LRU
• MathOps
• maxDist
• MinCuttingWords
• permutationStr
• RePack
• StringOps
• sumZero
• TreeOps
• TriangleFunc
• MirrorMaze

There is no license. If you want to use any code in book, please contact with me. Please feel free to refer the code with GitHub.