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README.md

Leetcode 分类顺序表

Array

基础

  • 27 Remove Element
  • 26 Remove Duplicates from Sorted Array
  • 80 Remove Duplicates from Sorted Array II
  • 277 Find the Celebrity
  • 189 Rotate Array
  • 41 First Missing Positive
  • 299 Bulls and Cows
  • 134 Gas Station
  • 118 Pascal's Triangle 很少考
  • 119 Pascal's Triangle II 很少考
  • 169 Majority Element 很少考
  • 229 Majority Element II 很少考
  • 274 H-Index
  • 275 H-Index II Binary Search
  • 243 Shortest Word Distance
  • 244 Shortest Word Distance II
  • 245 Shortest Word Distance III
  • 217 Contains Duplicate
  • 219 Contains Duplicate II 很少考
  • 220 Contains Duplicate III 很少考
  • 55 Jump Game
  • 45 Jump Game II
  • 121 Best Time to Buy and Sell Stock
  • 122 Best Time to Buy and Sell Stock II
  • 123 Best Time to Buy and Sell Stock III
  • 188 Best Time to Buy and Sell Stock IV
  • 309 Best Time to Buy and Sell Stock with Cooldown
  • 11 Container With Most Water
  • 42 Trapping Rain Water
  • 334 Increasing Triplet Subsequence
  • 128 Longest Consecutive Sequence
  • 164 Maximum Gap Bucket
  • 287 Find the Duplicate Number
  • 135 Candy 很少考
  • 330 Patching Array 很少考
  • 560 Subarray Sum Equals K

提高

  • 4 Median of Two Sorted Arrays 很少考
  • 321 Create Maximum Number 很少考
  • 327 Count of Range Sum
  • 289 Game of Life
  • 406 Queue Reconstruction by Height

Interval

  • 57 Insert Interval
  • 56 Merge Intervals
  • 252 Meeting Rooms
  • 253 Meeting Rooms II
  • 352 Data Stream as Disjoint Intervals TreeMap

Counter

  • 239 Sliding Window Maximum
  • 295 Find Median from Data Stream
  • 53 Maximum Subarray
  • 325 Maximum Size Subarray Sum Equals k
  • 209 Minimum Size Subarray Sum
  • 238 Product of Array Except Self
  • 152 Maximum Product Subarray
  • 228 Summary Ranges
  • 163 Missing Ranges

Counter

  • 88 Merge Sorted Array
  • 75 Sort Colors
  • 283 Move Zeroes
  • 376 Wiggle Subsequence
  • 280 Wiggle Sort
  • 324 Wiggle Sort II
  • 278 First Bad Version
  • 35 Search Insert Position
  • 33 Search in Rotated Sorted Array
  • 81 Search in Rotated Sorted Array II
  • 153 Find Minimum in Rotated Sorted Array
  • 154 Find Minimum in Rotated Sorted Array II
  • 162 Find Peak Element
  • 374 Guess Number Higher or Lower
  • 34 Find First and Last Position of Element in Sorted Array
  • 349 Intersection of Two Arrays
  • 350 Intersection of Two Arrays II
  • 315 Count of Smaller Numbers After Self
  • 300 Longest Increasing Subsequence
  • 354 Russian Doll Envelopes

String

基础

  • 28 Implement strStr()
  • 14 Longest Common Prefix
  • 58 Length of Last Word
  • 387 First Unique Character in a String
  • 383 Ransom Note
  • 344 Reverse String
  • 151 Reverse Words in a String
  • 186 Reverse Words in a String II
  • 345 Reverse Vowels of a String
  • 205 Isomorphic Strings
  • 293 Flip Game
  • 294 Flip Game II
  • 290 Word Pattern
  • 242 Valid Anagram
  • 49 Group Anagrams
  • 249 Group Shifted Strings
  • 87 Scramble String
  • 179 Largest Number 很少考
  • 6 ZigZag Conversion 很少考
  • 161 One Edit Distance
  • 38 Count and Say
  • 358 Rearrange String k Distance Apart
  • 316 Remove Duplicate Letters
  • 271 Encode and Decode Strings
  • 168 Excel Sheet Column Title
  • 171 Excel Sheet Column Number
  • 13 Roman to Integer
  • 12 Integer to Roman
  • 273 Integer to English Words
  • 246 Strobogrammatic Number
  • 247 Strobogrammatic Number II
  • 248 Strobogrammatic Number III 很少考

提高

  • 157 Read N Characters Given Read4
  • 158 Read N Characters Given Read4 II - Call multiple times
  • 68 Text Justification
  • 65 Valid Number

Substring

  • 76 Minimum Window Substring Sliding Window
  • 30 Substring with Concatenation of All Words Sliding Window
  • 3 Longest Substring Without Repeating Characters Sliding Window
  • 340 Longest Substring with At Most K Distinct Characters Sliding Window
  • 395 Longest Substring with At Least K Repeating Characters Sliding Window
  • 159 Longest Substring with At Most Two Distinct Characters Sliding Window

Palindrome

  • 125 Valid Palindrome
  • 266 Palindrome Permutation
  • 5 Longest Palindromic Substring
  • 9 Palindrome Number
  • 214 Shortest Palindrome
  • 336 Palindrome Pairs
  • 131 Palindrome Partitioning
  • 132 Palindrome Partitioning II
  • 267 Palindrome Permutation II

Parentheses

  • 20 Valid Parentheses
  • 22 Generate Parentheses
  • 32 Longest Valid Parentheses
  • 241 Different Ways to Add Parentheses
  • 301 Remove Invalid Parentheses

Subsequence

  • 392 Is Subsequence
  • 115 Distinct Subsequences
  • 187 Repeated DNA Sequences 很少考

Math

基础

  • 7 Reverse Integer
  • 165 Compare Version Numbers
  • 66 Plus One
  • 8 String to Integer (atoi)
  • 258 Add Digits
  • 67 Add Binary
  • 43 Multiply Strings
  • 29 Divide Two Integers
  • 69 Sqrt(x)
  • 50 Pow(x, n)
  • 367 Valid Perfect Square
  • 365 Water and Jug Problem
  • 204 Count Primes

Sum

  • 1 Two Sum
  • 167 Two Sum II - Input array is sorted
  • 15 3Sum
  • 16 3Sum Closest 很少考
  • 259 3Sum Smaller 很少考
  • 18 4Sum

Random

  • 478 Generate Random Point in a Circle

很少考

  • 231 Power of Two
  • 326 Power of Three
  • 342 Power of Four
  • 372 Super Pow
  • 233 Number of Digit One
  • 319 Bulb Switcher
  • 292 Nim Game
  • 202 Happy Number
  • 400 Nth Digit
  • 263 Ugly Number
  • 264 Ugly Number II
  • 306 Additive Number
  • 172 Factorial Trailing Zeroes
  • 343 Integer Break
  • 396 Rotate Function
  • 390 Elimination Game
  • 386 Lexicographical Numbers
  • 357 Count Numbers with Unique Digits
  • 360 Sort Transformed Array
  • 397 Integer Replacement
  • 368 Largest Divisible Subset
  • 621 Task Scheduler
  • 2400 Number of Ways to Reach a Position After Exactly k Steps
  • 1232 Check If It Is a Straight Line
  • 1266 Minimum Time Visiting All Points
  • 1401 Circle and Rectangle Overlapping
  • 818 Race Car

Tree

基础

  • 144 Binary Tree Preorder Traversal
  • 94 Binary Tree Inorder Traversal
  • 145 Binary Tree Postorder Traversal
  • 102 Binary Tree Level Order Traversal

Preorder

  • 100 Same Tree
  • 101 Symmetric Tree
  • 226 Invert Binary Tree preorder + BFS
  • 257 Binary Tree Paths
  • 112 Path Sum
  • 113 Path Sum II
  • 129 Sum Root to Leaf Numbers
  • 298 Binary Tree Longest Consecutive Sequence
  • 111 Minimum Depth of Binary Tree

Preorder

  • 104 Maximum Depth of Binary Tree
  • 110 Balanced Binary Tree
  • 124 Binary Tree Maximum Path Sum
  • 250 Count Univalue Subtrees
  • 366 Find Leaves of Binary Tree
  • 337 House Robber III postorder + preorder

DFS

  • 437 Path Sum III
  • 863 All Nodes Distance K in Binary Tree

BFS

  • 107 Binary Tree Level Order Traversal II
  • 103 Binary Tree Zigzag Level Order Traversal
  • 199 Binary Tree Right Side View BFS + preorder

BST

  • 98 Validate Binary Search Tree preorder
  • 235 Lowest Common Ancestor of a Binary Search Tree preorder
  • 236 Lowest Common Ancestor of a Binary Tree postorder
  • 108 Convert Sorted Array to Binary Search Tree binary search
  • 109 Convert Sorted List to Binary Search Tree binary search
  • 173 Binary Search Tree Iterator inorder
  • 230 Kth Smallest Element in a BST inorder
  • 297 Serialize and Deserialize Binary Tree BFS
  • 285 Inorder Successor in BST inorder
  • 270 Closest Binary Search Tree Value preorder
  • 272 Closest Binary Search Tree Value II inorder
  • 99 Recover Binary Search Tree inorder

重要程度

  • 156 Binary Tree Upside Down 很少考
  • 114 Flatten Binary Tree to Linked List 很少考
  • 255 Verify Preorder Sequence in Binary Search Tree 很少考
  • 333 Largest BST Subtree 很少考
  • 222 Count Complete Tree Nodes 很少考
  • 105 Construct Binary Tree from Preorder and Inorder Traversal 很少考
  • 106 Construct Binary Tree from Inorder and Postorder Traversal 很少考
  • 116 Populating Next Right Pointers in Each Node 重要
  • 117 Populating Next Right Pointers in Each Node II 重要
  • 314 Binary Tree Vertical Order Traversal 重要
  • 96 Unique Binary Search Trees 重要
  • 95 Unique Binary Search Trees II 很少考
  • 331 Verify Preorder Serialization of a Binary Tree 很少考

Backtracking

  • 37 Sudoku Solver
  • 51 N-Queens
  • 78 Subsets
  • 90 Subsets II
  • 77 Combinations
  • 39 Combination Sum
  • 40 Combination Sum II
  • 216 Combination Sum III
  • 377 Combination Sum IV Dynamic Programming
  • 254 Factor Combinations
  • 46 Permutations
  • 47 Permutations II
  • 31 Next Permutation String
  • 60 Permutation Sequence String
  • 291 Word Pattern II
  • 17 Letter Combinations of a Phone Number
  • 320 Generalized Abbreviation
  • 93 Restore IP Addresses 很少考
  • 282 Expression Add Operators
  • 140 Word Break II
  • 351 Android Unlock Patterns
  • 679 24 Game
  • 1947 Maximum Compatibility Score Sum

Dynamic Programming

一维

  • 70 Climbing Stairs
  • 62 Unique Paths
  • 63 Unique Paths II
  • 120 Triangle 很少考
  • 279 Perfect Squares
  • 139 Word Break
  • 375 Guess Number Higher or Lower II
  • 312 Burst Balloons
  • 322 Coin Change
  • 877 Stone Game
  • 818 Race Car

二维

  • 256 Paint House
  • 265 Paint House II
  • 64 Minimum Path Sum
  • 72 Edit Distance
  • 97 Interleaving String
  • 174 Dungeon Game
  • 221 Maximal Square
  • 85 Maximal Rectangle
  • 363 Max Sum of Rectangle No Larger Than K TreeSet
  • 712 Minimum ASCII Delete Sum for Two Strings
  • 1143 Longest Common Subsequence
  • 799 Champagne Tower

化简(降维?)

  • 198 House Robber
  • 213 House Robber II
  • 276 Paint Fence
  • 91 Decode Ways
  • 10 Regular Expression Matching
  • 44 Wildcard Matching

LinkedList

基础

  • 206 Reverse Linked List
  • 141 Linked List Cycle
  • 24 Swap Nodes in Pairs
  • 328 Odd Even Linked List
  • 92 Reverse Linked List II
  • 237 Delete Node in a Linked List
  • 19 Remove Nth Node From End of List
  • 83 Remove Duplicates from Sorted List
  • 203 Remove Linked List Elements
  • 82 Remove Duplicates from Sorted List II
  • 369 Plus One Linked List
  • 2 Add Two Numbers
  • 160 Intersection of Two Linked Lists
  • 21 Merge Two Sorted Lists

提高

  • 234 Palindrome Linked List
  • 143 Reorder List
  • 142 Linked List Cycle II
  • 148 Sort List
  • 25 Reverse Nodes in k-Group
  • 61 Rotate List
  • 86 Partition List
  • 23 Merge k Sorted Lists
  • 147 Insertion Sort List

Binary Search

  • 278 First Bad Version
  • 35 Search Insert Position
  • 33 Search in Rotated Sorted Array
  • 81 Search in Rotated Sorted Array II
  • 153 Find Minimum in Rotated Sorted Array
  • 154 Find Minimum in Rotated Sorted Array II
  • 162 Find Peak Element
  • 374 Guess Number Higher or Lower
  • 34 Find First and Last Position of Element in Sorted Array
  • 349 Intersection of Two Arrays
  • 350 Intersection of Two Arrays II
  • 315 Count of Smaller Numbers After Self
  • 300 Longest Increasing Subsequence
  • 354 Russian Doll Envelopes
  • 875 Koko Eating Bananas

Matrix

  • 48 Rotate Image
  • 54 Spiral Matrix
  • 59 Spiral Matrix II
  • 73 Set Matrix Zeroes
  • 311 Sparse Matrix Multiplication
  • 329 Longest Increasing Path in a Matrix
  • 378 Kth Smallest Element in a Sorted Matrix
  • 74 Search a 2D Matrix
  • 240 Search a 2D Matrix II
  • 370 Range Addition
  • 79 Word Search
  • 296 Best Meeting Point
  • 361 Bomb Enemy
  • 317 Shortest Distance from All Buildings
  • 302 Smallest Rectangle Enclosing Black Pixels
  • 36 Valid Sudoku
  • 37 Sudoku Solver
  • 1275 Find Winner on a Tic Tac Toe Game
  • 587 Erect the Fence

DFS & BFS

  • 200 Number of Islands
  • 286 Walls and Gates
  • 130 Surrounded Regions
  • 339 Nested List Weight Sum
  • 364 Nested List Weight Sum II
  • 127 Word Ladder
  • 51 N-Queens
  • 52 N-Queens II
  • 126 Word Ladder II

Stack & PriorityQueue

Stack

  • 155 Min Stack
  • 232 Implement Queue using Stacks
  • 225 Implement Stack using Queues
  • 150 Evaluate Reverse Polish Notation
  • 71 Simplify Path
  • 388 Longest Absolute File Path
  • 394 Decode String
  • 224 Basic Calculator
  • 227 Basic Calculator II
  • 385 Mini Parser
  • 84 Largest Rectangle in Histogram
  • 402 Remove K Digits
  • 496 Next Greater Element I
  • 456 132 Pattern
  • 739 Daily Temperatures

PriorityQueue

  • 215 Kth Largest Element in an Array
  • 347 Top K Frequent Elements
  • 313 Super Ugly Number 很少考
  • 373 Find K Pairs with Smallest Sums 很少考
  • 218 The Skyline Problem
  • 332 Reconstruct Itinerary
  • 341 Flatten Nested List Iterator

Bit Manipulation

  • 389 Find the Difference
  • 136 Single Number
  • 318 Maximum Product of Word Lengths

很少考

  • 393 UTF-8 Validation
  • 201 Bitwise AND of Numbers Range
  • 371 Sum of Two Integers emove Element
  • 338 Counting Bits
  • 89 Gray Code
  • 268 Missing Number
  • 191 Number of 1 Bits
  • 190 Reverse Bits
  • 137 Single Number II
  • 260 Single Number III

Topological Sort

  • 207 Course Schedule
  • 210 Course Schedule II
  • 269 Alien Dictionary

Random

  • 384 Shuffle an Array
  • 398 Random Pick Index
  • 382 Linked List Random Node
  • 380 Insert Delete GetRandom O(1)
  • 381 Insert Delete GetRandom O(1) - Duplicates allowed
  • 138 Copy List with Random Pointer

Graph

基础

  • 133 Clone Graph
  • 399 Evaluate Division
  • 310 Minimum Height Trees
  • 743 Network Delay Time

图形学

  • 149 Max Points on a Line
  • 335 Self Crossing 很少考
  • 356 Line Reflection 很少考
  • 391 Perfect Rectangle 很少考
  • 223 Rectangle Area 很少考

二分图

  • 785 Is Graph Bipartite?

最小生成树

  • 1135 Connecting Cities With Minimum Cost

Union Find

  • 261 Graph Valid Tree
  • 323 Number of Connected Components in an Undirected Graph
  • 305 Number of Islands II
  • 721 Accounts Merge

Trie

  • 211 Add and Search Word - Data structure design
  • 208 Implement Trie (Prefix Tree)
  • 212 Word Search II

扫描线

  • 218 The Skyline Problem
  • 253 Meeting Rooms II
  • 759 Employee Free Time

双指针

  • 438 Find All Anagrams in a String

贪心

  • 871 Minimum Number of Refueling Stops

Design

  • 359 Logger Rate Limiter
  • 346 Moving Average from Data Stream Sliding Window
  • 362 Design Hit Counter
  • 281 Zigzag Iterator
  • 284 Peeking Iterator
  • 251 Flatten 2D Vector
  • 288 Unique Word Abbreviation
  • 170 Two Sum III - Data structure design
  • 348 Design Tic-Tac-Toe
  • 379 Design Phone Directory
  • 353 Design Snake Game
  • 146 LRU Cache
  • 355 Design Twitter
  • 303 Range Sum Query - Immutable
  • 304 Range Sum Query 2D - Immutable
  • 307 Range Sum Query - Mutable BIT & ST
  • 308 Range Sum Query 2D - Mutable BIT & ST
  • 460 LFU Cache
  • 1166 Design File System
  • 706 Design HashMap

Leetcode 重点 250+ 题(建议前面 400+ 题全部刷完再精刷此 250+ 题)

  • 1 Two Sum
  • 3 Longest Substring Without Repeating Characters
  • 4 Median of Two Sorted Arrays
  • 5 Longest Palindromic Substring
  • 7 Reverse Integer
  • 8 String to Integer (atoi)
  • 10 Regular Expression Matching
  • 11 Container With Most Water
  • 12 Integer to Roman
  • 13 Roman to Integer
  • 15 3Sum
  • 17 Letter Combinations of a Phone Number
  • 18 4Sum
  • 20 Valid Parentheses
  • 22 Generate Parentheses
  • 23 Merge k Sorted Lists
  • 26 Remove Duplicates from Sorted Array
  • 27 Remove Element
  • 28 Implement strStr()
  • 29 Divide Two Integers
  • 31 Next Permutation
  • 32 Longest Valid Parentheses
  • 33 Search in Rotated Sorted Array
  • 34 Find First and Last Position of Element in Sorted Array
  • 35 Search Insert Position
  • 36 Valid Sudoku
  • 37 Sudoku Solver
  • 38 Count and Say
  • 39 Combination Sum
  • 40 Combination Sum II
  • 41 First Missing Positive
  • 42 Trapping Rain Water
  • 43 Multiply Strings
  • 44 Wildcard Matching
  • 45 Jump Game II
  • 46 Permutations
  • 47 Permutations II
  • 48 Rotate Image
  • 49 Group Anagrams
  • 50 Pow(x, n)
  • 51 N-Queens
  • 52 N-Queens II
  • 53 Maximum Subarray
  • 54 Spiral Matrix
  • 55 Jump Game
  • 56 Merge Intervals
  • 57 Insert Interval
  • 59 Spiral Matrix II
  • 60 Permutation Sequence
  • 62 Unique Paths
  • 64 Minimum Path Sum
  • 65 Valid Number
  • 66 Plus One
  • 67 Add Binary
  • 68 Text Justification
  • 69 Sqrt(x)
  • 70 Climbing Stairs
  • 71 Simplify Path
  • 72 Edit Distance
  • 74 Search a 2D Matrix
  • 75 Sort Colors
  • 76 Minimum Window Substring
  • 77 Combinations
  • 78 Subsets
  • 79 Word Search
  • 80 Remove Duplicates from Sorted Array II
  • 81 Search in Rotated Sorted Array II
  • 82 Remove Duplicates from Sorted List II
  • 84 Largest Rectangle in Histogram
  • 85 Maximal Rectangle
  • 88 Merge Sorted Array
  • 90 Subsets II
  • 91 Decode Ways
  • 96 Unique Binary Search Trees
  • 98 Validate Binary Search Tree
  • 101 Symmetric Tree
  • 104 Maximum Depth of Binary Tree
  • 108 Convert Sorted Array to Binary Search Tree
  • 110 Balanced Binary Tree
  • 111 Minimum Depth of Binary Tree
  • 112 Path Sum
  • 113 Path Sum II
  • 115 Distinct Subsequences
  • 116 Populating Next Right Pointers in Each Node
  • 117 Populating Next Right Pointers in Each Node II
  • 121 Best Time to Buy and Sell Stock
  • 122 Best Time to Buy and Sell Stock II
  • 123 Best Time to Buy and Sell Stock III
  • 124 Binary Tree Maximum Path Sum
  • 125 Valid Palindrome
  • 126 Word Ladder II
  • 127 Word Ladder
  • 128 Longest Consecutive Sequence
  • 130 Surrounded Regions
  • 133 Clone Graph
  • 134 Gas Station
  • 138 Copy List with Random Pointer
  • 139 Word Break
  • 140 Word Break II
  • 142 Linked List Cycle II
  • 146 LRU Cache
  • 149 Max Points on a Line
  • 150 Evaluate Reverse Polish Notation
  • 152 Maximum Product Subarray
  • 153 Find Minimum in Rotated Sorted Array
  • 154 Find Minimum in Rotated Sorted Array II
  • 155 Min Stack
  • 157 Read N Characters Given Read4
  • 158 Read N Characters Given Read4 II - Call multiple times
  • 161 One Edit Distance
  • 162 Find Peak Element
  • 163 Missing Ranges
  • 168 Excel Sheet Column Title
  • 171 Excel Sheet Column Number
  • 173 Binary Search Tree Iterator
  • 174 Dungeon Game
  • 186 Reverse Words in a String II
  • 188 Best Time to Buy and Sell Stock IV
  • 189 Rotate Array
  • 191 Number of 1 Bits
  • 198 House Robber
  • 200 Number of Islands
  • 201 Bitwise AND of Numbers Range
  • 202 Happy Number
  • 204 Count Primes
  • 205 Isomorphic Strings
  • 207 Course Schedule
  • 208 Implement Trie (Prefix Tree)
  • 209 Minimum Size Subarray Sum
  • 210 Course Schedule II
  • 211 Add and Search Word - Data structure design
  • 212 Word Search II
  • 213 House Robber II
  • 214 Shortest Palindrome
  • 215 Kth Largest Element in an Array
  • 216 Combination Sum III
  • 217 Contains Duplicate
  • 218 The Skyline Problem
  • 219 Contains Duplicate II
  • 220 Contains Duplicate III
  • 221 Maximal Square
  • 224 Basic Calculator
  • 225 Implement Stack using Queues
  • 226 Invert Binary Tree
  • 227 Basic Calculator II
  • 228 Summary Ranges
  • 230 Kth Smallest Element in a BST
  • 231 Power of Two
  • 232 Implement Queue using Stacks
  • 235 Lowest Common Ancestor of a Binary Search Tree
  • 236 Lowest Common Ancestor of a Binary Tree
  • 238 Product of Array Except Self
  • 239 Sliding Window Maximum
  • 240 Search a 2D Matrix II
  • 241 Different Ways to Add Parentheses
  • 242 Valid Anagram
  • 244 Shortest Word Distance II
  • 245 Shortest Word Distance III
  • 249 Group Shifted Strings
  • 251 Flatten 2D Vector
  • 252 Meeting Rooms
  • 253 Meeting Rooms II
  • 254 Factor Combinations
  • 256 Paint House
  • 257 Binary Tree Paths
  • 261 Graph Valid Tree
  • 263 Ugly Number
  • 264 Ugly Number II
  • 265 Paint House II
  • 268 Missing Number
  • 269 Alien Dictionary
  • 270 Closest Binary Search Tree Value
  • 271 Encode and Decode Strings
  • 273 Integer to English Words
  • 274 H-Index
  • 275 H-Index II
  • 276 Paint Fence
  • 277 Find the Celebrity
  • 278 First Bad Version
  • 279 Perfect Squares
  • 280 Wiggle Sort
  • 282 Expression Add Operators
  • 283 Move Zeroes
  • 284 Peeking Iterator
  • 285 Inorder Successor in BST
  • 286 Walls and Gates
  • 287 Find the Duplicate Number
  • 288 Unique Word Abbreviation
  • 289 Game of Life
  • 290 Word Pattern
  • 291 Word Pattern II
  • 293 Flip Game
  • 294 Flip Game II
  • 295 Find Median from Data Stream
  • 296 Best Meeting Point
  • 297 Serialize and Deserialize Binary Tree
  • 298 Binary Tree Longest Consecutive Sequence
  • 299 Bulls and Cows
  • 300 Longest Increasing Subsequence
  • 301 Remove Invalid Parentheses
  • 302 Smallest Rectangle Enclosing Black Pixels
  • 305 Number of Islands II
  • 307 Range Sum Query - Mutable
  • 308 Range Sum Query 2D - Mutable
  • 309 Best Time to Buy and Sell Stock with Cooldown
  • 311 Sparse Matrix Multiplication
  • 312 Burst Balloons
  • 314 Binary Tree Vertical Order Traversal
  • 316 Remove Duplicate Letters
  • 317 Shortest Distance from All Buildings
  • 318 Maximum Product of Word Lengths
  • 322 Coin Change
  • 323 Number of Connected Components in an Undirected Graph
  • 324 Wiggle Sort II
  • 325 Maximum Size Subarray Sum Equals k
  • 329 Longest Increasing Path in a Matrix
  • 334 Increasing Triplet Subsequence
  • 336 Palindrome Pairs
  • 337 House Robber III
  • 338 Counting Bits
  • 339 Nested List Weight Sum
  • 340 Longest Substring with At Most K Distinct Characters
  • 341 Flatten Nested List Iterator
  • 346 Moving Average from Data Stream
  • 347 Top K Frequent Elements
  • 348 Design Tic-Tac-Toe
  • 350 Intersection of Two Arrays II
  • 351 Android Unlock Patterns
  • 352 Data Stream as Disjoint Intervals
  • 353 Design Snake Game
  • 354 Russian Doll Envelopes
  • 355 Design Twitter
  • 359 Logger Rate Limiter
  • 361 Bomb Enemy
  • 362 Design Hit Counter
  • 364 Nested List Weight Sum II
  • 367 Valid Perfect Square
  • 374 Guess Number Higher or Lower
  • 375 Guess Number Higher or Lower II
  • 376 Wiggle Subsequence
  • 377 Combination Sum IV
  • 378 Kth Smallest Element in a Sorted Matrix
  • 379 Design Phone Directory
  • 380 Insert Delete GetRandom O(1)
  • 381 Insert Delete GetRandom O(1) - Duplicates allowed
  • 384 Shuffle an Array
  • 385 Mini Parser
  • 389 Find the Difference
  • 394 Decode String
  • 398 Random Pick Index
  • 875 Koko Eating Bananas
  • 621 Task Scheduler
  • 743 Network Delay Time
  • 785 Is Graph Bipartite?
  • 739 Daily Temperatures
  • 787 Cheapest Flights Within K Stops
  • 438 Find All Anagrams in a String
  • 721 Accounts Merge
  • 706 Design HashMap
  • 1143 Longest Common Subsequence
  • 2400 Number of Ways to Reach a Position After Exactly k Steps
  • 679 24 Game
  • 1232 Check If It Is a Straight Line
  • 1266 Minimum Time Visiting All Points
  • 877 Stone Game
  • 1401 Circle and Rectangle Overlapping
  • 818 Race Car
  • 587 Erect the Fence
  • 799 Champagne Tower