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awangdev/leet-code

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Snapshot of awangdev/leet-code: 4.3k★, Java, Backend. Java Solutions to problems on LintCode/LeetCode

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Stars★ 4.3k

Forks⑂ 30

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Top 21 contributors to awangdev/leet-code

Leetcode#	Problem	Level	Tags	Time	Space	Language	Sequence
N/A	Jump Game II.java	Hard	[Array, Coordinate DP, DP, Greedy]	O(n)	O(1)	Java	0
N/A	Majority Number II.java	Medium	[Enumeration, Greedy]			Java	1
N/A	Search a 2D Matrix II.java	Medium	[Binary Search, Divide and Conquer]			Java	2
N/A	Missing Ranges.java	Medium	[Array]			Java	3
N/A	Inorder Successor in BST.java	Medium	[BST, Tree]			Java	4
N/A	Convert Integer A to Integer B.java	Easy	[Bit Manipulation]			Java	5
N/A	Backpack VI.java	Medium	[Backpack DP, DP]			Java	6
N/A	Total Occurrence of Target.java	Medium	[]			Java	7
N/A	House Robber III.java	Medium	[DFS, DP, Status DP, Tree]			Java	8
N/A	Binary Tree Maximum Path Sum II.java	Medium	[DFS, Tree]			Java	9
N/A	Backpack V.java	Medium	[Backpack DP, DP]			Java	10
N/A	Closest Number in Sorted Array.java	Easy	[Binary Search]			Java	11
N/A	Convert Expression to Polish Notation.java	Hard	[Binary Tree, DFS, Expression Tree, Stack]			Java	12
N/A	Missing Number.java	Easy	[Array, Bit Manipulation, Math]			Java	13
N/A	Restore IP Addresses.java	Medium	[Backtracking, DFS, String]			Java	14
N/A	Linked List Cycle II.java	Medium	[Linked List, Math, Two Pointers]			Java	15
N/A	Unique Binary Search Tree.java	Medium	[BST, DP, Tree]			Java	16
N/A	Largest Number.java	Medium	[Sort]			Java	17
N/A	Reverse String.java	Easy	[String, Two Pointers]			Java	18
N/A	Triangles.java	Medium	[Array, Coordinate DP, DFS, DP, Memoization]			Java	19
N/A	Frog Jump.java	Hard	[DP, Hash Table]			Java	20
N/A	Summary Ranges.java	Medium	[Array]			Java	21
N/A	Sliding Window Median.java	Hard	[Design, Heap, MaxHeap, MinHeap, Sliding Window]			Java	22
N/A	Single Number III.java	Medium	[Bit Manipulation]			Java	23
N/A	Trailing Zeros.java	Easy	[Math]			Java	24
N/A	Fast Power.java	Medium	[DFS, Divide and Conquer]			Java	25
N/A	Perfect Rectangle.java	Hard	[Design, Geometry, Hash Table]			Java	26
N/A	Total Hamming Distance.java	Medium	[Bit Manipulation]	O(n)	O(1), 32-bit array	Java	27
N/A	Word Pattern.java	Easy	[]			Java	28
N/A	Two Sum IV - Input is a BST.java	Easy	[Tree]			Java	29
N/A	Count 1 in Binary.java	Easy	[Bit Manipulation]			Java	30
N/A	Two Lists Sum.java	Medium	[Linked List]			Java	31
N/A	Flatten 2D Vector.java	Medium	[Design]			Java	32
N/A	Hamming Distance.java	Easy	[]			Java	33
N/A	Find the Weak Connected Component in the Directed Graph.java	Medium	[Union Find]			Java	34
N/A	Interval Minimum Number.java	Medium	[Binary Search, Divide and Conquer, Lint, Segment Tree]			Java	35
N/A	Stone Game.java	Medium	[DP]			Java	36
N/A	Longest Increasing Continuous subsequence II.java	Medium	[Array, Coordinate DP, DP, Memoization]			Java	37
N/A	Plus One.java	Easy	[Array, Math]			Java	38
N/A	Paint Fence.java	Easy	[DP, Sequence DP]	O(n)	O(n)	Java	39
N/A	Line Reflection.java	Medium	[Hash Table, Math]	O(n)	O(n)	Java	40
N/A	Binary Representation.java	Hard	[Bit Manipulation, String]			Java	41
N/A	Longest Consecutive Sequence.java	Hard	[Array, Hash Table, Union Find]			Java	42
N/A	Find Minimum in Rotated Sorted Array.java	Medium	[Array, Binary Search]			Java	43
N/A	Binary Tree Longest Consecutive Sequence II.java	Medium	[DFS, Divide and Conquer, Double Recursive, Tree]			Java	44
N/A	Minimum Subarray.java	Easy	[Array, DP, Greedy, Sequence DP, Subarray]	O(m)	O(1)	Java	45
N/A	Connecting Graph.java	Medium	[Union Find]			Java	46
N/A	Count of Smaller Number.java	Medium	[Binary Search, Lint, Segment Tree]			Java	47
N/A	Binary Gap.java	Easy	[Bit Manipulation]	O(n), n = # of bits	O(1)	Java	48
N/A	Flip Game II.java	Medium	[Backtracking, DFS, DP]			Java	49
N/A	Subtree of Another Tree.java	Easy	[DFS, Divide and Conquer, Tree]			Java	50
N/A	Binary Tree Level Order Traversal II.java	Medium	[BFS, Tree]			Java	51
N/A	Maximum Average Subarray I.java	Easy	[Array, Subarray]	O(n)	O(1)	Java	52
N/A	IndexMatch.java	Easy	[]			Java	53
N/A	Walls and Gates.java	Medium	[BFS, DFS]			Java	54
N/A	Decode String.java	Medium	[DFS, Divide and Conquer, Stack]			Java	55
N/A	The Maze.java	Medium	[BFS, DFS]			Java	56
N/A	Palindromic Substrings.java	Medium	[DP, String]			Java	57
N/A	Rearrange String k Distance Apart.java	Hard	[Greedy, Hash Table, Heap]			Java	58
N/A	Count and Say.java	Easy	[Basic Implementation, String]			Java	59
N/A	Median of Two Sorted Arrays.java	Hard	[Array, Binary Search, DFS, Divide and Conquer]			Java	60
N/A	Perfect Squares.java	Medium	[BFS, DP, Math, Partition DP]			Java	61
N/A	Word Search.java	Medium	[Array, Backtracking, DFS]			Java	62
N/A	Backpack II.java	Medium	[Backpack DP, DP]			Java	63
N/A	Reshape the Matrix.java	Easy	[]			Java	64
N/A	Update Bits.java	Medium	[Bit Manipulation]			Java	65
N/A	Triangle Count.java	Medium	[Array]			Java	66
N/A	Remove Duplicate Letters.java	Hard	[Greedy, Hash Table, Stack]			Java	67
N/A	Permutation Sequence.java	Medium	[Backtracking, Math]			Java	68
N/A	House Robber II.java	Medium	[DP, Sequence DP, Status DP]			Java	69
N/A	O(1) Check Power of 2.java	Easy	[Bit Manipulation]			Java	70
N/A	Letter Combinations of a Phone Number.java	Medium	[Backtracking, String]			Java	71
N/A	Backspace String Compare.java	Easy	[Stack, Two Pointers]			Java	72
N/A	Minimum Size Subarray Sum.java	Medium	[Array, Binary Search, Subarray, Two Pointers]	O(n)	O(1)	Java	73
N/A	Implement Stack using Queues.java	Easy	[Design, Stack]			Java	74
N/A	Minimum Absolute Difference in BST.java	Easy	[BST]			Java	75
N/A	Maximum Binary Tree.java	Medium	[Stack, Tree]			Java	76
N/A	ColorGrid.java	Medium	[Design, Hash Table]			Java	77
N/A	HashWithArray.java	Easy	[]			Java	78
N/A	Flood Fill.java	Easy	[DFS]			Java	79
N/A	Construct Binary Tree from Inorder and Postorder Traversal.java	Medium	[Array, DFS, Divide and Conquer, Tree]			Java	80
N/A	Backpack.java	Medium	[Backpack DP, DP]			Java	81
N/A	Longest Common Subsequence.java	Medium	[DP, Double Sequence DP, Sequence DP]			Java	82
N/A	Peeking Iterator.java	Medium	[Design]			Java	83
N/A	Orderly Queue.java	Hard	[Math, String]			Java	84
N/A	QuickSort.java	Medium	[Quick Sort, Sort]			Java	85
N/A	Maximal Rectangle.java	Hard	[Array, DP, Hash Table, Stack]			Java	86
N/A	Expression Evaluation.java	Hard	[Binary Tree, DFS, Expression Tree, Minimum Binary Tree, Stack]			Java	87
N/A	Subtree.java	Easy	[DFS, Tree]			Java	88
N/A	LFU Cache.java	Hard	[Design, Hash Table]			Java	89
N/A	Cosine Similarity.java	Easy	[Basic Implementation]			Java	90
N/A	Scramble String.java	Hard	[DP, Interval DP, String]			Java	91
N/A	Redundant Connection.java	Medium	[BFS, DFS, Graph, Tree, Union Find]			Java	92
N/A	Rotate List.java	Medium	[Linked List, Two Pointers]			Java	93
N/A	Swap Nodes in Pairs.java	Medium	[Linked List]			Java	94
N/A	Longest Increasing Continuous subsequence.java	Easy	[Array, Coordinate DP, DP]			Java	95
N/A	K Edit Distance.java	Hard	[DP, Double Sequence DP, Sequence DP, Trie]			Java	96
N/A	Combinations.java	Medium	[Backtracking, Combination, DFS]			Java	97
N/A	Max Area of Island.java	Easy	[Array, DFS]			Java	98
N/A	Sort List.java	Medium	[Divide and Conquer, Linked List, Merge Sort, Sort]			Java	99
N/A	Find Peak Element.java	Medium	[Array, Binary Search]			Java	100
N/A	Word Search II.java	Hard	[Backtracking, DFS, Trie]			Java	101
N/A	K Empty Slots.java	Hard	[Array, BST, TreeSet]			Java	102
N/A	Gray Code.java	Medium	[Backtracking]			Java	103
N/A	Encode and Decode TinyURL.java	Medium	[Hash Table, Math]			Java	104
N/A	Game of Life.java	Medium	[Array]			Java	105
N/A	Compare Version Numbers.java	Medium	[String]			Java	106
N/A	Singleton.java	Easy	[Design]			Java	107
N/A	Ugly Number.java	Medium	[Math]			Java	108
N/A	Russian Doll Envelopes.java	Hard	[Binary Search, Coordinate DP, DP]			Java	109
N/A	Rehashing.java	Medium	[Hash Table]			Java	110
N/A	Kth Smallest Sum In Two Sorted Arrays.java	Hard	[]			Java	111
N/A	Longest Common Substring.java	Medium	[DP, Double Sequence DP, Sequence DP, String]			Java	112
N/A	Rotate Image.java	Medium	[Array, Enumeration]			Java	113
N/A	Backpack III.java	Hard	[Backpack DP, DP]			Java	114
N/A	Combination Sum IV.java	Medium	[Array, Backpack DP, DP]			Java	115
N/A	Number of Longest Increasing Subsequence.java	Medium	[Coordinate DP, DP]	O(n^2)		Java	116
N/A	Permutation Index.java	Easy	[]			Java	117
N/A	4Sum.java	Medium	[Hash Table]			Java	118
N/A	Shortest Palindrome.java	Hard	[KMP, String]			Java	119
N/A	Convert Sorted Array to Binary Search Tree.java	Easy	[DFS, Divide and Conquer, Tree]			Java	120
N/A	Populating Next Right Pointers in Each Node.java	Medium	[DFS, Divide and Conquer, Tree]			Java	121
N/A	Space Replacement.java	Medium	[String]			Java	122
N/A	Contiguous Array.java	Medium	[Hash Table]			Java	123
N/A	Reverse Linked List II .java	Medium	[Linked List]			Java	124
N/A	Palindrome Pairs.java	Hard	[Hash Table, String, Trie]			Java	125
N/A	Find Peak Element II.java	Hard	[Binary Search, DFS, Divide and Conquer]			Java	126
N/A	Minimum Height Trees.java	Medium	[BFS, Graph]			Java	127
N/A	Longest Substring Without Repeating Characters.java	Medium	[Hash Table, String, Two Pointers]			Java	128
N/A	Fraction to Recurring Decimal.java	Medium	[Hash Table, Math]			Java	129
N/A	Wiggle Sort.java	Medium	[Array, Sort]			Java	130
N/A	Reverse Words in a String II.java	Medium	[String]			Java	131
N/A	Remove Node in Binary Search Tree.java	Hard	[BST]			Java	132
N/A	Reorder List.java	Medium	[Linked List]			Java	133
N/A	Redundant Connection II.java	Hard	[DFS, Graph, Tree, Union Find]			Java	134
N/A	[tool] Quick Select - Median.java	Easy	[Array, Lint, Quick Select, Quick Sort, Two Pointers]	O(n)	O(logN)	Java	135
N/A	Swap Bits.java	Easy	[Bit Manipulation]			Java	136
N/A	Friends Of Appropriate Ages.java	Medium	[Array, Math]			Java	137
N/A	Longest Increasing Subsequence.java	Medium	[Binary Search, Coordinate DP, DP, Memoization]	O(n^2) dp, O(nLogN) binary search	O(n)	Java	138
N/A	Power of Two.java	Easy	[Bit Manipulation, Math]			Java	139
N/A	Min Stack.java	Easy	[Design, Stack]			Java	140
N/A	Count of Smaller Number before itself.java	Hard	[]			Java	141
N/A	Majority Number III.java	Medium	[Hash Table, Linked List]			Java	142
N/A	Number of Digit One.java	Hard	[Math]			Java	143
N/A	Tweaked Identical Binary Tree.java	Easy	[DFS, Tree]			Java	144
N/A	Search Range in Binary Search Tree .java	Medium	[BST, Binary Tree]			Java	145
N/A	Best Time to Buy and Sell Stock III.java	Hard	[Array, DP, Sequence DP]			Java	146
N/A	Design Search Autocomplete System.java	Hard	[Design, Hash Table, MinHeap, PriorityQueue, Trie]	input: O(x), where x = possible words, constructor: O(mn) m = max length, n = # of words	O(n^2), n = # of possible words, n = # of trie levels; mainlay saving the `Map<S, freq>`	Java	147
N/A	Subsets II.java	Medium	[Array, BFS, Backtracking, DFS]	O(2^n)		Java	148
N/A	One Edit Distance.java	Medium	[String]			Java	149
N/A	Segment Tree Modify.java	Medium	[Binary Tree, DFS, Divide and Conquer, Lint, Segment Tree]			Java	150
N/A	Distinct Subsequences.java	Hard	[DP, String]			Java	151
N/A	Insert Node in a Binary Search Tree .java	Easy	[BST]			Java	152
N/A	Container With Most Water.java	Medium	[Array, Two Pointers]			Java	153
N/A	Word Ladder.java	Medium	[BFS]			Java	154
N/A	Single Number II.java	Medium	[Bit Manipulation]			Java	155
N/A	Heaters.java	Easy	[]			Java	156
N/A	Kth Smallest Element in a BST.java	Medium	[BST, DFS, Stack, Tree]			Java	157
N/A	Robot Room Cleaner.java	Hard	[Backtracking, DFS]			Java	158
N/A	Coins in a Line II.java	Medium	[Array, DP, Game Theory, Memoization, MiniMax]			Java	159
N/A	Partition List.java	Medium	[Linked List, Two Pointers]			Java	160
N/A	Classical Binary Search.java	Easy	[Binary Search]			Java	161
N/A	Wood Cut.java	Medium	[Binary Search]			Java	162
N/A	Connecting Graph III.java	Medium	[Union Find]			Java	163
N/A	Invert Binary Tree.java	Easy	[BFS, DFS, Tree]			Java	164
N/A	Remove Duplicates from Unsorted List.java	Medium	[Linked List]			Java	165
N/A	Maximum Size Subarray Sum Equals k.java	Medium	[Hash Table, PreSum, Subarray]	O(n)	O(n)	Java	166
N/A	The Smallest Difference.java	Medium	[Array, Sort, Two Pointers]			Java	167
N/A	Unique Binary Search Tree II.java	Medium	[BST, DP, Divide and Conquer, Tree]			Java	168
N/A	Encode and Decode Strings.java	Medium	[String]			Java	169
N/A	Remove Duplicates from Sorted List II.java	Medium	[Linked List]			Java	170
N/A	Subarray Sum II.java	Hard	[Array, Binary Search, Two Pointers]			Java	171
N/A	Matrix Zigzag Traversal.java	Easy	[]			Java	172
N/A	Ones and Zeroes.java	Hard	[DP]			Java	173
N/A	Number of Connected Components in an Undirected Graph.java	Medium	[BFS, DFS, Graph, Union Find]			Java	174
N/A	Submatrix Sum.java	Medium	[Array, Hash Table, PreSum]			Java	175
N/A	Zigzag Iterator.java	Medium	[BST]			Java	176
N/A	Find the Connected Component in the Undirected Graph.java	Medium	[BFS, DFS]			Java	177
N/A	Implement Stack.java	Easy	[Stack]			Java	178
N/A	Number of Airplane in the sky.java	Medium	[Array, Interval, PriorityQueue, Sort, Sweep Line]			Java	179
N/A	Surrounded Regions.java	Medium	[BFS, DFS, Matrix DFS, Union Find]			Java	180
N/A	Wildcard Matching.java	Hard	[Backtracking, DP, Double Sequence DP, Greedy, Sequence DP, String]			Java	181
N/A	Expression Add Operators.java	Hard	[Backtracking, DFS, Divide and Conquer, String]	O(4^n)	O(4^n)	Java	182
N/A	Cracking the Safe.java	Hard	[DFS, Greedy, Math]			Java	183
N/A	Unique Word Abbreviation.java	Medium	[Design, Hash Table]			Java	184
N/A	Best Time to Buy and Sell Stock IV.java	Hard	[DP, Sequence DP]			Java	185
N/A	Find Minimum in Rotated Sorted Array II.java	Hard	[Array, Binary Search]			Java	186
N/A	Longest Valid Parentheses.java	Hard	[Coordinate DP, Stack, String]			Java	187
N/A	Ugly Number II.java	Medium	[DP, Enumeration, Heap, Math, PriorityQueue]	O(n)	O(n)	Java	188
N/A	Add Two Numbers II.java	Medium	[Linked List]			Java	189
N/A	Maximum Average Subarray II.java	Review	[Array, Binary Search, PreSum]			Java	190
N/A	Expression Tree Build.java	Hard	[Binary Tree, Expression Tree, Minimum Binary Tree, Stack]			Java	191
N/A	Merge Two Binary Trees.java	Easy	[DFS, Tree]			Java	192
N/A	Copy Books.java	Hard	[Binary Search, DP, Partition DP]			Java	193
N/A	Power of Three.java	Easy	[Math]			Java	194
N/A	Sort Colors II.java	Medium	[Partition, Quick Sort, Sort, Two Pointers]			Java	195
N/A	Maximum Subarray III.java	Review	[]			Java	196
N/A	Path Sum II.java	Easy	[Backtracking, DFS, Tree]			Java	197
N/A	Segment Tree Query II.java	Medium	[Binary Tree, DFS, Divide and Conquer, Lint, Segment Tree]			Java	198
N/A	Shortest Distance from All Buildings.java	Hard	[BFS]			Java	199
N/A	Brick Wall.java	Medium	[Hash Table]	O(mn)	O(X), X = max wall width	Java	200
N/A	Longest Increasing Path in a Matrix.java	Hard	[Coordinate DP, DFS, DP, Memoization, Topological Sort]			Java	201
N/A	Interleaving String.java	Hard	[DP, String]			Java	202
N/A	Shuffle an Array.java	Medium	[Permutation]			Java	203
N/A	Recover Binary Search Tree.java	Hard	[BST, DFS, Tree]			Java	204
N/A	My Calendar I.java	Medium	[Array, TreeMap]			Java	205
N/A	Evaluate Reverse Polish Notation.java	Medium	[Stack]	O(n)	O(n)	Java	206
N/A	Counting Bits.java	Medium	[Bit Manipulation, Bitwise DP, DP]			Java	207
N/A	Sort Letters by Case.java	Medium	[Partition, Sort, String, Two Pointers]			Java	208
N/A	Two Strings Are Anagrams.java	Easy	[]			Java	209
N/A	Two Sum II - Input array is sorted.java	Medium	[Array, Binary Search, Two Pointers]			Java	210
N/A	[HackerRank]. Change to Anagram.java	Easy	[String]			Java	211
N/A	Implement Queue using Stacks.java	Easy	[Design, Stack]			Java	212
N/A	Basic Calculator.java	Hard	[Binary Tree, Expression Tree, Math, Minimum Binary Tree, Stack]			Java	213
N/A	Word Squares.java	Hard	[Backtracking, Trie]			Java	214
N/A	Insertion Sort List.java	Medium	[Linked List, Sort]			Java	215
N/A	Interval Sum.java	Medium	[Binary Search, Lint, Segment Tree]			Java	216
N/A	Strobogrammatic Number II.java	Medium	[DFS, Enumeration, Math, Sequence DFS]			Java	217
N/A	The Maze II.java	Medium	[BFS, DFS, PriorityQueue]			Java	218
N/A	k Sum.java	Hard	[DP]			Java	219
N/A	Coins in a Line III.java	Hard	[Array, DP, Game Theory, Interval DP, Memoization]			Java	220
N/A	Convert Sorted List to Binary Search Tree.java	Medium	[BST, DFS, Divide and Conquer, Linked List]			Java	221
N/A	Guess Number Higher or Lower.java	Easy	[Binary Search]			Java	222
N/A	Trapping Rain Water II.java	Hard	[BFS, Heap, MinHeap, PriorityQueue]			Java	223
N/A	Bricks Falling When Hit.java	Hard	[Union Find]			Java	224
N/A	Subarray Sum Closest.java	Medium	[PreSum, PriorityQueue, Sort, Subarray]	O(nlogn)	O(n)	Java	225
N/A	Burst Balloons.java	Hard	[DP, Divide and Conquer, Interval DP, Memoization]			Java	226
N/A	Partition Array by Odd and Even.java	Easy	[Array, Two Pointers]			Java	227
N/A	Best Time to Buy and Sell Stock with Cooldown.java	Medium	[DP]			Java	228
N/A	Palindrome Partitioning II.java	Hard	[DP, Partition DP]			Java	229
N/A	Convert Binary Search Tree to Sorted Doubly Linked List (extra space).java	Medium	[Linked List, Stack, Tree]	O(n)	O(n)	Java	230
N/A	Kth Largest Element in an Array.java	Medium	[Divide and Conquer, Heap, MinHeap, PriorityQueue, Quick Sort]			Java	231
N/A	Sliding Puzzle.java	Hard	[BFS, Graph]			Java	232
N/A	Interval Sum II.java	Hard	[Binary Search, Lint, Segment Tree]			Java	233
N/A	Add Digits.java	Easy	[Math]			Java	234
N/A	HashWithCustomizedClass(LinkedList).java	Medium	[Hash Table]			Java	235
N/A	Maximum Vacation Days.java	Hard	[DP]			Java	236
N/A	Smallest Subtree with all the Deepest Nodes.java	Medium	[DFS, Divide and Conquer, Tree]	O(n)	O(n)	Java	237
N/A	Kth Smallest Element in a Sorted Matrix.java	Medium	[Binary Search, Heap]	O(n + klogn)	O(n)	Java	238
N/A	Combination Sum III.java	Medium	[Array, Backtracking, Combination, DFS]			Java	239
N/A	Last Position of Target.java	Easy	[Binary Search]			Java	240
N/A	Path Sum III.java	Easy	[DFS, Double Recursive, Tree]			Java	241
N/A	Convert Expression to Reverse Polish Notation.java	Hard	[Binary Tree, DFS, Expression Tree, Stack]			Java	242
N/A	Complete Binary Tree.java	Easy	[BFS, Tree]			Java	243
N/A	Best Time to Buy and Sell Stock with Transaction Fee.java	Medium	[Array, DP, Greedy, Sequence DP, Status DP]	O(n)	O(n), O(1) rolling array	Java	244
N/A	Pow(x, n).java	Medium	[Binary Search, Math]			Java	245
N/A	Maximum Subarray II.java	Medium	[Array, DP, Greedy, PreSum, Sequence DP, Subarray]			Java	246
N/A	Sort Colors.java	Medium	[Array, Partition, Quick Sort, Sort, Two Pointers]			Java	247
N/A	Word Ladder II.java	Hard	[Array, BFS, Backtracking, DFS, Hash Table, String]			Java	248
N/A	Sum of Two Integers.java	Easy	[Bit Manipulation]			Java	249
N/A	Predict the Winner.java	Medium	[DP, MiniMax]			Java	250
N/A	Connecting Graph II.java	Medium	[Union Find]			Java	251
N/A	Search Insert Position.java	Easy	[]			Java	252
N/A	Longest Univalue Path.java	Easy	[]			Java	253
N/A	Contains Duplicate III.java	Medium	[BST]			Java	254
N/A	Spiral Matrix.java	Medium	[Array, Enumeration]			Java	255
N/A	Next Closest Time.java	Medium	[Basic Implementation, Enumeration, String]			Java	256
N/A	Group Shifted Strings.java	Medium	[Hash Table, String]			Java	257
N/A	The Maze III.java	Hard	[BFS, DFS, PriorityQueue]			Java	258
N/A	Coins in a Line.java	Medium	[DP, Game Theory, Greedy]			Java	259
N/A	Binary Tree Longest Consecutive Sequence.java	Medium	[DFS, Divide and Conquer, Tree]			Java	260
N/A	The Spiral Matrix II.java	Medium	[Array]			Java	261
N/A	Trim a Binary Search Tree.java	Easy	[BST, Tree]			Java	262
N/A	Number Of Corner Rectangles.java	Medium	[DP, Math]			Java	263
N/A	Queue Reconstruction by Height.java	Medium	[Greedy]			Java	264
N/A	Minimum Swaps To Make Sequences Increasing.java	Medium	[Coordinate DP, DP, Status DP]			Java	265
N/A	Interleaving Positive and Negative Numbers.java	Medium	[Two Pointers]			Java	266
N/A	Path Sum IV.java	Medium	[DFS, Hash Table, Tree]			Java	267
N/A	Excel Sheet Column Number.java	Easy	[Math]			Java	268
N/A	Target Sum.java	Medium	[DFS, DP]			Java	269
N/A	Partition Array.java	Medium	[Array, Quick Sort, Sort, Two Pointers]			Java	270
N/A	Bus Routes.java	Hard	[BFS]			Java	271
N/A	Max Sum of Rectangle No Larger Than K.java	Hard	[Array, BST, Binary Search, DP, Queue, TreeSet]			Java	272
N/A	String Permutation.java	Easy	[]			Java	273
N/A	Maximum XOR of Two Numbers in an Array.java	Medium	[Bit Manipulation, Trie]			Java	274
N/A	Search for a Range.java	Medium	[Array, Binary Search]			Java	275
N/A	Palindrome Permutation II.java	Medium	[Backtracking, Permutation]			Java	276
N/A	Populating Next Right Pointers in Each Node II.java	Medium	[DFS, Tree]	O(n)	O(1)	Java	277
N/A	Nim Game.java	Easy	[Brainteaser, DP, Game Theory]			Java	278
N/A	Search a 2D Matrix.java	Medium	[Array, Binary Search]			Java	279
N/A	Largest Rectangle in Histogram.java	Hard	[Array, Monotonous Stack, Stack]			Java	280
[lint]	[lint]. Merge k Sorted Arrays.java	Medium	[Heap, MinHeap, PriorityQueue]	O(nlogk)	O(k)	Java	281
[lint]	[lint]. Segment Tree Build II.java	Medium	[Binary Tree, Divide and Conquer, Lint, Segment Tree]			Java	282
[lint]	[lint]. Nth to Last Node in List.java	Easy	[Linked List, Lint]			Java	283
[lint]	[lint]. Product of Array Exclude Itself.java	Medium	[Array, Lint]			Java	284
[lint]	[lint]. Compare Strings.java	Easy	[Lint, String]			Java	285
[lint]	[lint]. Segment Tree Query.java	Medium	[Binary Tree, DFS, Divide and Conquer, Lint, Segment Tree]			Java	286
[lint]	[lint]. HashHeap.java	Hard	[HashHeap, Heap, Lint]			Java	287
[lint]	[lint]. Longest Words.java	Easy	[Hash Table, Lint, String]			Java	288
[lint]	[lint]. Anagrams.java	Medium	[Array, Hash Table, Lint]	O(n)	O(n)	Java	289
[lint]	[lint]. 3 Sum Closest.java	Medium	[Array, Lint, Two Pointers]			Java	290
[lint]	[lint]. Unique Characters.java	Easy	[Array, Lint, String]			Java	291
[lint]	[lint]. Lowest Common Ancestor II.java	Easy	[Hash Table, Lint, Tree]			Java	292
[lint]	[lint]. Heapify.java	Medium	[HashHeap, Heap, Lint, MinHeap]			Java	293
[lint]	[lint]. Subarray Sum.java	Easy	[Array, Hash Table, Lint, PreSum, Subarray]	O(n)	O(n)	Java	294
[lint]	[lint]. Recover Rotated Sorted Array.java	Easy	[Array, Lint]			Java	295
[lint]	[lint]. 2 Sum II.java	Medium	[Array, Binary Search, Lint, Two Pointers]			Java	296
[lint]	[lint]. Segment Tree Build.java	Medium	[Binary Tree, Divide and Conquer, Lint, Segment Tree]			Java	297
[tool]	[tool]. MergeSort.java	Medium	[Lint, Merge Sort, Sort]	O(mlogn)	O(n)	Java	298
[tool]	[tool]. Hash Function.java	Easy	[Hash Table, Lint]	O(1) get	O(n) store map	Java	299
[tool]	[tool]. UnionFind.java	Medium	[Lint, Union Find]	O(n), with Path Compression O(mN), with Union by Rank O(logN)	O(n)	Java	300
[tool]	[tool]. Topological Sorting.java	Medium	[BFS, DFS, Lint, Topological Sort]	O(V + E)	O(V + E)	Java	301
36	36. Valid Sudoku.java	Easy	[Enumeration, Hash Table]	(mn)	(mn)	Java	302
359	359. Logger Rate Limiter.java	Easy	[Design, Hash Table]	O(1)	O(n)	Java	303
198	198. House Robber.java	Easy	[DP, Sequence DP, Status DP]	O(n)	O(n) or rolling array O(1)	Java	304
21	21. Merge Two Sorted Lists.java	Easy	[Linked List]	O(n)	O(1)	Java	305
102	102. Binary Tree Level Order Traversal.java	Medium	[BFS, DFS, Tree]	O(n)	O(n)	Java	306
788	788. Rotated Digits.java	Easy	[Basic Implementation, String]	O(n)	O(n)	Java	307
42	42. Trapping Rain Water.java	Hard	[Array, Stack, Two Pointers]	O(n)	O(1)	Java	308
347	347. Top K Frequent Elements.java	Medium	[Hash Table, Heap, MaxHeap, MinHeap, PriorityQueue]	O(n)	O(n)	Java	309
269	269. Alien Dictionary.java	Hard	[BFS, Backtracking, DFS, Graph, Topological Sort]	O(n), n = # of graph edges	O(n)	Java	310
237	237. Delete Node in a Linked List.java	Easy	[Linked List]			Java	311
142	142. Linked List Cycle II.java	Medium	[Cycle Detection, Linked List, Slow Fast Pointer, Two Pointers]	O(n)	O(1)	Java	312
448	448. Find All Numbers Disappeared in an Array.java	Easy	[Array, Bucket Sort]	O(n)	O(1)	Java	313
360	360. Sort Transformed Array.java	Medium	[Math, Two Pointers]	O(n)	O(n) store result	Java	314
22	22. Generate Parentheses.java	Medium	[Backtracking, DFS, Sequence DFS, String]	O(2^n)	O(2^n)	Java	315
849	849. Maximize Distance to Closest Person.java	Easy	[Array, Basic Implementation, Two Pointers]	O(n)	O(1)	Java	316
408	408. Valid Word Abbreviation.java	Easy	[Basic Implementation, String]			Java	317
415	415. Add Strings.java	Easy	[Basic Implementation, Math, String]	O(n)	O(n)	Java	318
83	83. Remove Duplicates from Sorted List.java	Easy	[Linked List]			Java	319
1108	1108. Defanging an IP Address.java	Easy	[Basic Implementation, String]			Java	320
1021	1021. Remove Outermost Parentheses.java	Easy	[Stack]			Java	321
236	236. Lowest Common Ancestor of a Binary Tree.java	Medium	[DFS, Tree]	O(n)	O(n)	Java	322
766	766. Toeplitz Matrix.java	Easy	[Array]	O(mn)	O(1)	Java	323
953	953. Verifying an Alien Dictionary.java	Easy	[Hash Table]	O(nm)	O(1)	Java	324
1053	1053. Previous Permutation With One Swap.java	Medium	[Array, Greedy, Permutation]	O(n)	O(1)	Java	325
1213	1213. Intersection of Three Sorted Arrays.java	Easy	[Hash Table, Two Pointers]	O(m + n + h) two pointers approach	O(1)	Java	326
383	383. Ransom Note.java	Easy	[Basic Implementation, String]			Java	327
56	56. Merge Intervals.java	Medium	[Array, PriorityQueue, Sort, Sweep Line]	O(nlogn)	O(n)	Java	328
252	252. Meeting Rooms.java	Easy	[PriorityQueue, Sort, Sweep Line]	O(nlogn)	O(1)	Java	329
665	665. Non-decreasing Array.java	Easy	[Array]	O(n)	O(1)	Java	330
843	843. Guess the Word.java	Hard	[MiniMax]	TODO	TODO	Java	331
986	986. Interval List Intersections.java	Medium	[Two Pointers]	O(n)	O(1)	Java	332
76	76. Minimum Window Substring.java	Hard	[Hash Table, Sliding Window, String, Two Pointers]	O(n)	O(1)	Java	333
293	293. Flip Game.java	Easy	[String]			Java	334
244	244. Shortest Word Distance II.java	Medium	[Array, Design, Hash Table, Two Pointers]	O(n) to build map, O(a + b) to query	O(n)	Java	335
686	686. Repeated String Match.java	Easy	[Basic Implementation, Edge Case, String]			Java	336
80	80.Remove Duplicates from Sorted Array II.java	Medium	[Array, Two Pointers]			Java	337
301	301. Remove Invalid Parentheses.java	Hard	[BFS, DFS, DP]			Java	338
111	111. Minimum Depth of Binary Tree.java	Easy	[BFS, DFS, Tree]	O(n)	O(n)	Java	339
1216	1216. Valid Palindrome III.java	Hard	[DFS, DP, Memoization, String]	O(n^2)	O(n^2)	Java	340
7	7. Reverse Integer.java	Easy	[Math]	O(n)	O(1)	Java	341
5	5. Longest Palindromic Substring.java	Medium	[DP, String]	O(n^2)	O(n^2)	Java	342
303	303. Range Sum Query - Immutable.java	Easy	[DP, PreSum]	O(1) query, O(n) setup	O(n)	Java	343
674	674. Longest Continuous Increasing Subsequence.java	Easy	[Array, Coordinate DP, DP, Sliding Window]	O(n)	O(1)	Java	344
1007	1007. Minimum Domino Rotations For Equal Row.java	Medium	[Array, Greedy]	O(n)	O(1)	Java	345
485	485. Max Consecutive Ones.java	Easy	[Array, Basic Implementation]	O(n)	O(1)	Java	346
896	896. Monotonic Array.java	Easy	[Array]			Java	347
207	207. Course Schedule.java	Medium	[BFS, Backtracking, DFS, Graph, Topological Sort]	O(n)	O(n)	Java	348
327	327. Count of Range Sum.java	Hard	[BIT, Divide and Conquer, Merge Sort, PreSum, Segment Tree]	O(nlogn)	O(n)	Java	349
987	987. Vertical Order Traversal of a Binary Tree.java	Medium	[BFS, Binary Tree, DFS, Hash Table, Tree]			Java	350
26	26.Remove Duplicates from Sorted Array.java	Easy	[Array, Two Pointers]			Java	351
429	429. N-ary Tree Level Order Traversal.java	Medium	[BFS, Tree]	O(n)	O(n)	Java	352
275	275. H-Index II.java	Medium	[Binary Search]	O(logN)	O(1) extra	Java	353
204	204. Count Primes.java	Easy	[Hash Table, Math]			Java	354
58	58. Length of Last Word.java	Easy	[String]			Java	355
496	496. Next Greater Element I.java	Easy	[Hash Table, Stack]	O(n)	O(n)	Java	356
41	41. First Missing Positive.java	Hard	[Analysis, Array, Edge Case]	O(n)	O(1)	Java	357
694	694. Number of Distinct Islands.java	Medium	[DFS, Hash Table]	O(n)	O(n)	Java	358
717	717. 1-bit and 2-bit Characters.java	Easy	[Array]			Java	359
53	53. Maximum Subarray.java	Easy	[Array, DFS, DP, Divide and Conquer, PreSum, Sequence DP, Subarray]	O(n)	O(n), O(1) rolling array	Java	360
152	152. Maximum Product Subarray.java	Medium	[Array, DP, PreProduct, Subarray]	O(n)	O(1)	Java	361
199	199. Binary Tree Right Side View.java	Medium	[BFS, DFS, Tree]	O(n)	O(n)	Java	362
259	259. 3Sum Smaller.java	Medium	[Array, Sort, Two Pointers]			Java	363
977	977. Squares of a Sorted Array.java	Easy	[Array, Two Pointers]	O(n)	O(n)	Java	364
824	824. Goat Latin.java	Easy	[Basic Implementation, String]	O(n)	O(1)	Java	365
308	308. Range Sum Query 2D - Mutable.java	Hard	[Binary Indexed Tree, Segment Tree]	build(n), update(logn), rangeRuery(logn + k)	O(n)	Java	366
1203	1203. Sort Items by Groups Respecting Dependencies.java	Hard	[BFS, DFS, Graph, Topological Sort]	O(V + E) to traverse the graph, #nodes + #edges	O(V + E)	Java	367
1153	1153. String Transforms Into Another String.java	Hard	[Graph]	O(n)	O(n)	Java	368
1008	1008. Construct Binary Search Tree from Preorder Traversal.java	Medium	[DFS, Tree]	O(n)	O(n)	Java	369
151	151. Reverse Words in a String.java	Medium	[String]	O(n)		Java	370
855	855. Exam Room.java	Medium	[PriorityQueue, Sort, TreeMap, TreeSet]	O(logn)	O(n)	Java	371
31	31. Next Permutation.java	Medium	[Array, Permutation]	O(n)	O(1)	Java	372
518	518. Coin Change 2.java	Medium	[Backpack DP, DP]	O(n)	O(n)	Java	373
405	405. Convert a Number to Hexadecimal.java	Easy	[Bit Manipulation]			Java	374
850	850. Rectangle Area II.java	Hard	[Segment Tree, Sweep Line]	O(n^2)	O(n)	Java	375
515	515. Find Largest Value in Each Tree Row.java	Medium	[BFS, DFS, Tree]	O(n)	O(n)	Java	376
253	253. Meeting Rooms II.java	Medium	[Greedy, Heap, PriorityQueue, Sort, Sweep Line]	O(nlogn)	O(n)	Java	377
1161	1161. Maximum Level Sum of a Binary Tree.java	Medium	[BFS, DFS, Graph]	O(n) visit all nodes	O(n)	Java	378
509	509. Fibonacci Number.java	Easy	[DP, Math, Memoization]			Java	379
221	221. Maximal Square.java	Medium	[Coordinate DP, DP]	O(mn)	O(mn)	Java	380
131	131. Palindrome Partitioning.java	Medium	[Backtracking, DFS]	O(2^n)	O(n^2)	Java	381
136	136. Single Number.java	Easy	[Bit Manipulation, Hash Table]			Java	382
222	222. Count Complete Tree Nodes.java	Medium	[Binary Search, DFS, Tree]	O(n)	O(h)	Java	383
257	257. Binary Tree Paths.java	Easy	[Backtracking, Binary Tree, DFS]	O(n)	O(nlogn)	Java	384
543	543. Diameter of Binary Tree.java	Easy	[Tree]	O(n) when non-balanced	O(n) when non-balanced	Java	385
398	398. Random Pick Index.java	Medium	[Reservior Sampling]	O(n)	O(n) for input int[], O(1) extra space used	Java	386
238	238. Product of Array Except Self.java	Medium	[Array, PreProduct]	O(n)	O(1)	Java	387
1060	1060. Missing Element in Sorted Array.java	Medium	[Binary Search]	O(logn)	O(1)	Java	388
1048	1048. Longest String Chain.java	Medium	[Bucket Sort, DP, Hash Table, Sort]	O(n)	O(n)	Java	389
67	67. Add Binary.java	Easy	[Math, String, Two Pointers]			Java	390
299	299. Bulls and Cows.java	Medium	[Hash Table]	O(n)	O(n)	Java	391
557	557. Reverse Words in a String III.java	Easy	[String]			Java	392
203	203. Remove Linked List Elements.java	Easy	[Linked List]			Java	393
1219	1219. Path with Maximum Gold.java	Medium	[Backtracking, DFS]	O(n^2)	O(n) recursive depth	Java	394
266	266. Palindrome Permutation.java	Easy	[Hash Table]	O(n)	O(n)	Java	395
62	62. Unique Path.java	Medium	[Array, Coordinate DP, DP]	O(mn)	O(mn), rolling array O(n)	Java	396
1091	1091. Shortest Path in Binary Matrix.java	Medium	[BFS]	O(n^2)		Java	397
1110	1110. Delete Nodes And Return Forest.java	Medium	[DFS, Divide and Conquer, Tree]	O(n)	O(logn)	Java	398
1249	1249. Minimum Remove to Make Valid Parentheses.java	Medium	[Stack, String]	O(n)	O(n)	Java	399
15	15. 3Sum.java	Medium	[Array, Sort, Two Pointers]	O(n^2)		Java	400
311	311. Sparse Matrix Multiplication.java	Medium	[Hash Table]	O(mnk), where `m = A.row`, `n = B.col`, `k = A.col = B.row`	O(1) extra	Java	401
339	339. Nested List Weight Sum.java	Easy	[BFS, DFS, NestedInteger]	O(n)	O(h), h = levels	Java	402
322	322. Coin Change.java	Medium	[Backpack DP, DFS, DP, Memoization]	O(n * S)	O(S)	Java	403
55	55. Jump Game.java	Medium	[Array, DP, Greedy]	O(n)	O(1)	Java	404
173	173. Binary Search Tree Iterator.java	Medium	[BST, Design, Stack, Tree]	O(1) average	O(h)	Java	405
140	140. Word Break II.java	Hard	[Backtracking, DFS, DP, Hash Table, Memoization]	O(n!)	O(n!)	Java	406
51	51. N-Queens.java	Hard	[Backtracking]	O(n!)	O(n^2)	Java	407
875	875. Koko Eating Bananas.java	Medium	[Binary Search]	O(n*logM)	O(1)	Java	408
189	189. Rotate Array.java	Easy	[Array, Rotation]			Java	409
19	19. Remove Nth Node From End of List.java	Medium	[Linked List, Two Pointers]	O(n)	O(1)	Java	410
134	134. Gas Station.java	Medium	[Greedy]	O(n)	O(1)	Java	411
119	119. Pascal's Triangle II.java	Easy	[Array, Basic Implementation]	O(k^2), pascal triangle size	O(k^2)	Java	412
1197	1197. Minimum Knight Moves.java	Medium	[BFS]	O(8^n)	O(8^n)	Java	413
493	493. Reverse Pairs.java	Medium	[BST, Binary Indexed Tree, Divide and Conquer, Merge Sort, Segment Tree]			Java	414
1306	1306. Jump Game III.java	Medium	[BFS, Graph]	O(n)	O(n)	Java	415
305	305. Number of Islands II.java	Hard	[Union Find]	O(k * log(mn))	O(mn)	Java	416
206	206. Reverse Linked List.java	Easy	[Linked List]			Java	417
277	277. Find the Celebrity.java	Medium	[Adjacency Matrix, Array, Graph, Greedy, Pruning]	O(n)	O(1)	Java	418
741	741. Cherry Pickup.java	Hard	[DFS, DP]	O(n^3)	O(n^3), memo size	Java	419
168	168. Excel Sheet Column Title.java	Easy	[Math]	O(n)	O(1)	Java	420
104	104. Maximum Depth of Binary Tree.java	Easy	[DFS, Tree]			Java	421
349	349. Intersection of Two Arrays.java	Easy	[Binary Search, Hash Table, Sort, Two Pointers]	O(m + n)	O(m + n)	Java	422
443	443. String Compression.java	Easy	[Basic Implementation, String]			Java	423
297	297. Serialize and Deserialize Binary Tree.java	Hard	[BFS, DFS, Deque, Design, Divide and Conquer, Tree]	O(n)	O(n)	Java	424
46	46. Permutations.java	Medium	[BFS, Backtracking, DFS, Permutation]	O(n!)	O(n!)	Java	425
844	844. Backspace String Compare.java	Easy	[Stack, Two Pointers]	O(n)	O(1)	Java	426
9	9. Palindrome Number.java	Easy	[Math]			Java	427
1094	1094. Car Pooling.java	Medium	[Greedy, Heap, PriorityQueue, Sort]	O(n)	O(1) only use bucket size 1000	Java	428
245	245. Shortest Word Distance III.java	Medium	[Array, Design, Hash Table, Two Pointers]	O(n)	O(1)	Java	429
1117	1117. Building H2O.java	Medium	[Lock, Semaphore, Thread]			Java	430
973	973. K Closest Points to Origin.java	Medium	[Divide and Conquer, Heap, Sort]	O(klogk)	O(k)	Java	431
771	771. Jewels and Stones.java	Easy	[Hash Table]	O(n)	O(n)	Java	432
200	200. Number of Islands.java	Medium	[BFS, DFS, Matrix DFS, Union Find]	O(n)	O(n)	Java	433
141	141. Linked List Cycle.java	Easy	[Cycle Detection, Linked List, Slow Fast Pointer, Two Pointers]	O(n)	O(1)	Java	434
567	567. Permutation in String.java	Medium	[Sliding Window, Two Pointers]	O(m + n)	O(1)	Java	435
727	727. Minimum Window Subsequence.java	Hard	[DP, Hash Table, Sliding Window, String, Two Pointers]	O(n^2)	O(1)	Java	436
158	158. Read N Characters Given Read4 II - Call multiple times.java	Hard	[Enumeration, String]	O(n)	O(n)	Java	437
369	369. Plus One Linked List.java	Medium	[Linked List]	O(n)	O(1)	Java	438
211	211. Add and Search Word - Data structure design.java	Medium	[Backtracking, Design, Trie]	O(n) to search and to add word	< O(mn), depends on the input. m = # of words	Java	439
43	43. Multiply Strings.java	Medium	[Math, String]	O(mn)	O(mn)	Java	440
621	621. Task Scheduler.java	Medium	[Array, Enumeration, Greedy, PriorityQueue, Queue]	O(n)	O(1)	Java	441
680	680. Valid Palindrome II.java	Easy	[String]			Java	442
295	295. Find Median from Data Stream.java	Hard	[Design, Heap, MaxHeap, MinHeap]	O(1) get, O(logn) addNum	O(n)	Java	443
70	70. Climbing Stairs.java	Easy	[DP, Memoization, Sequence DP]			Java	444
747	747. Largest Number At Least Twice of Others.java	Easy	[Array]			Java	445
315	315. Count of Smaller Numbers After Self.java	Hard	[BST, Binary Indexed Tree, Binary Search, Divide and Conquer, Segment Tree]	O(nlogn)	O(n)	Java	446
239	239. Sliding Window Maximum.java	Hard	[Deque, Heap, Sliding Window]	O(n)	O(n)	Java	447
47	47. Permutations II.java	Medium	[Backtracking, DFS]			Java	448
332	332. Reconstruct Itinerary.java	Medium	[Backtracking, DFS, Graph]	O(n^n)	O(m)	Java	449
88	88. Search in Rotated Sorted Array II.java	Medium	[Array, Binary Search]	O(logn), worst O(n)	O(1)	Java	450
561	561. Array Partition I.java	Easy	[Array]	O(nlogn)	O(1)	Java	451
387	387. First Unique Character in a String.java	Easy	[Hash Table, String]	O(n)	O(256) = O(1)	Java	452
345	345. Reverse Vowels of a String.java	Easy	[String, Two Pointers]			Java	453
39	39. Combination Sum.java	Medium	[Array, Backtracking, Combination, DFS]	O(k * 2^n), k = avg rst length	O(k) stack depth, if not counting result size	Java	454
10	10. Regular Expression Matching.java	Hard	[Backtracking, DP, Double Sequence DP, Sequence DP, String]			Java	455
367	367. Valid Perfect Square.java	Easy	[Binary Search, Math]	O(logN)	O(1)	Java	456
270	270. Closest Binary Search Tree Value.java	Easy	[BST, Binary Search, Tree]	O(logn)	O(1)	Java	457
28	28. Implement strStr().java	Easy	[String, Two Pointers]			Java	458
1106	1106. Parsing A Boolean Expression.java	Hard	[DFS, Stack, String]			Java	459
144	144. Binary Tree Preorder Traversal.java	Medium	[BFS, DFS, Stack, Tree]	O(n)	O(n)	Java	460
852	852. Peak Index in a Mountain Array.java	Easy	[Binary Search]	O(logn)	O(1)	Java	461
146	146. LRU Cache.java	Medium	[Design, Doubly Linked List, Hash Table, Linked List]	O(1)	O(1)	Java	462
110	110. Balanced Binary Tree.java	Easy	[DFS, Tree]			Java	463
1040	1040. Moving Stones Until Consecutive II.java	Medium	[Array, Sliding Window]	O(nlogn)	O(n)	Java	464
246	246. Strobogrammatic Number.java	Easy	[Enumeration, Hash Table, Math, Two Pointers]	O(n)	O(1)	Java	465
100	100. Same Tree.java	Easy	[BFS, DFS, Tree]	O(n)	O(logn)	Java	466
307	307. Range Sum Query - Mutable.java	Medium	[Binary Indexed Tree, Segment Tree]	build O(n), query (logn +k), update O(logn)	O(n)	Java	467
88	88. Merge Sorted Array.java	Easy	[Array, Two Pointers]	O(n)	O(1)	Java	468
319	319. Bulb Switcher.java	Medium	[Brainteaser, Math]	O(1)	O(1)	Java	469
112	112. Path Sum.java	Easy	[DFS, Tree]			Java	470
463	463. Island Perimeter.java	Easy	[Hash Table]	O(n)		Java	471
170	170. Two Sum III - Data structure design.java	Easy	[Design, Hash Table, Memoization]	O(n)	O(n)	Java	472
122	122. Best Time to Buy and Sell Stock II.java	Easy	[Array, DP, Greedy, Sequence DP, Status DP]	O(n)	O(1) greedy, O(n) dp	Java	473
715	715. Range Module.java	Hard	[Segment Tree, TreeSet]	query O(logn), update O(n)	O(n)	Java	474
12	12. Integer to Roman.java	Medium	[Basic Implementation, Math, String]	O(n)	O(n)	Java	475
14	14. Longest Common Prefix.java	Easy	[String]			Java	476
243	243. Shortest Word Distance.java	Easy	[Array, Two Pointers]	O(n)	O(1)	Java	477
414	414. Third Maximum Number.java	Easy	[Array, PriorityQueue]			Java	478
1267	1267. Count Servers that Communicate.java	Medium	[Array, Graph]	O(mn)	O(m + n)	Java	479
20	20. Valid Parentheses.java	Easy	[Stack, String]	O(n)	O(n)	Java	480
893	893. Groups of Special-Equivalent Strings.java	Easy	[Basic Implementation, String]			Java	481
427	427. Construct Quad Tree.java	Medium	[Tree]	O(n^2)	O(n^2)	Java	482
981	981. Time Based Key-Value Store.java	Medium	[Binary Search, Hash Table, TreeMap]	set O(1), get(logn)	O(n)	Java	483
169	169. Majority Element.java	Easy	[Array, Bit Manipulation, Divide and Conquer, Moore Voting, Sort]	O(n)	O(1)	Java	484
234	234. Palindrome Linked List.java	Easy	[Linked List, Two Pointers]	O(n)	O(1)	Java	485
202	202. Happy Number.java	Easy	[Hash Table, Math]	O(m), m iterations	O(m), m number in set	Java	486
69	69. Sqrt(x).java	Easy	[Binary Search, Math]			Java	487
876	876. Middle of Linked List.java	Easy	[Linked List]			Java	488
1026	1026. Maximum Difference Between Node and Ancestor.java	Medium	[DFS, Tree]	O(n)	O(logn)	Java	489
78	78. Subsets.java	Medium	[Array, BFS, Backtracking, Bit Manipulation, DFS]	O(2^n)	O(2^n)	Java	490
432	432. All One Data Structure.java	Hard	[Design, Doubly Linked List]	O(1)	O(n)	Java	491
380	380. Insert Delete GetRandom O(1).java	Medium	[Array, Design, Hash Table]	O(1) avg	O(n)	Java	492
560	560. Subarray Sum Equals K.java	Medium	[Array, Hash Table, PreSum, Subarray]	O(n)	O(n)	Java	493
219	219. Contains Duplicate II.java	Easy	[Array, Hash Table]	O(n)	O(n)	Java	494
91	91. Decode Ways.java	Medium	[DP, Partition DP, String]	O(n)	O(n)	Java	495
205	205. Isomorphic Strings.java	Easy	[Hash Table]	O(n)	O(n)	Java	496
639	639. Decode Ways II.java	Hard	[DP, Enumeration, Partition DP]	O(n)	O(n)	Java	497
346	346. Moving Average from Data Stream.java	Easy	[Design, Queue, Sliding Window]	O(1) for `next()`	O(size) for fixed storage	Java	498
145	145. Binary Tree Postorder Traversal.java	Medium	[Stack, Tree, Two Stacks]	O(n)	O(n)	Java	499

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Does awangdev/leet-code have a project website?

No homepage URL was recorded for awangdev/leet-code in TopGit's last sync. The README tab above frequently contains screenshots and demo links, or check the repository description on GitHub.

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awangdev/leet-code is tracked by TopGit in the Backend category, with 4.3k GitHub stars and written in Java. Browse the Backend topic page on TopGit to compare it against similar projects by stars and activity.

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What else is in the Backend space?

awangdev/leet-code is tracked by TopGit under the Backend category, alongside 6 GitHub-tagged topics. Trending and Topics pages list peer repositories of comparable stars and language.

What is awangdev/leet-code?

awangdev/leet-code (awangdev/leet-code) is a Java project on GitHub. From the project's own README: Java Solutions to problems on LintCode/LeetCode

Where do I read more about awangdev/leet-code?

This TopGit page is a snapshot — the READ ME tab shows the project's own README content (links stripped, images preserved). The GitHub repository at github.com/awangdev/leet-code is the definitive source.

Read full README in the tab above.

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