{ %%%%%%%%%%%%%%%%%%%%%%%%------------------------------------} 40.5% 475/1172| ID | Title | Difficulty | Status |
|---|---|---|---|
| 1 | Two Sum | Easy | Accepted |
| 2 | Add Two Numbers | Medium | Accepted |
| 3 | Longest Substring Without Repeating Characters | Medium | Accepted |
| 4 | Median of Two Sorted Arrays | Hard | Accepted |
| 5 | Longest Palindromic Substring | Medium | Accepted |
| 6 | ZigZag Conversion | Medium | Accepted |
| 7 | Reverse Integer | Easy | Accepted |
| 8 | String to Integer (atoi) | Medium | |
| 9 | Palindrome Number | Easy | Accepted |
| 10 | Regular Expression Matching | Hard | Accepted |
| 11 | Container With Most Water | Medium | Accepted |
| 12 | Integer to Roman | Medium | Accepted |
| 13 | Roman to Integer | Easy | Accepted |
| 14 | Longest Common Prefix | Easy | Accepted |
| 15 | 3Sum | Medium | Accepted |
| 16 | 3Sum Closest | Medium | Accepted |
| 17 | Letter Combinations of a Phone Number | Medium | Accepted |
| 18 | 4Sum | Medium | Accepted |
| 19 | Remove Nth Node From End of List | Medium | Accepted |
| 20 | Valid Parentheses | Easy | Accepted |
| 21 | Merge Two Sorted Lists | Easy | Accepted |
| 22 | Generate Parentheses | Medium | Accepted |
| 23 | Merge k Sorted Lists | Hard | Accepted |
| 24 | Swap Nodes in Pairs | Medium | Accepted |
| 25 | Reverse Nodes in k-Group | Hard | Accepted |
| 26 | Remove Duplicates from Sorted Array | Easy | Accepted |
| 27 | Remove Element | Easy | Accepted |
| 28 | Implement strStr() | Easy | Accepted |
| 29 | Divide Two Integers | Medium | Accepted |
| 30 | Substring with Concatenation of All Words | Hard | |
| 31 | Next Permutation | Medium | Accepted |
| 32 | Longest Valid Parentheses | Hard | Accepted |
| 33 | Search in Rotated Sorted Array | Medium | Accepted |
| 34 | Find First and Last Position of Element in Sorted Array | Medium | Accepted |
| 35 | Search Insert Position | Easy | Accepted |
| 36 | Valid Sudoku | Medium | Accepted |
| 37 | Sudoku Solver | Hard | Accepted |
| 38 | Count and Say | Easy | Accepted |
| 39 | Combination Sum | Medium | Accepted |
| 40 | Combination Sum II | Medium | Accepted |
| 41 | First Missing Positive | Hard | Accepted |
| 42 | Trapping Rain Water | Hard | Accepted |
| 43 | Multiply Strings | Medium | Accepted |
| 44 | Wildcard Matching | Hard | Accepted |
| 45 | Jump Game II | Hard | Accepted |
| 46 | Permutations | Medium | Accepted |
| 47 | Permutations II | Medium | Accepted |
| 48 | Rotate Image | Medium | Accepted |
| 49 | Group Anagrams | Medium | Accepted |
| 50 | Pow(x, n) | Medium | Accepted |
| 51 | N-Queens | Hard | Accepted |
| 52 | N-Queens II | Hard | Accepted |
| 53 | Maximum Subarray | Easy | Accepted |
| 54 | Spiral Matrix | Medium | Accepted |
| 55 | Jump Game | Medium | Accepted |
| 56 | Merge Intervals | Medium | Accepted |
| 57 | Insert Interval | Hard | Accepted |
| 58 | Length of Last Word | Easy | Accepted |
| 59 | Spiral Matrix II | Medium | Accepted |
| 60 | Permutation Sequence | Medium | Accepted |
| 61 | Rotate List | Medium | Accepted |
| 62 | Unique Paths | Medium | Accepted |
| 63 | Unique Paths II | Medium | Accepted |
| 64 | Minimum Path Sum | Medium | Accepted |
| 65 | Valid Number | Hard | Accepted |
| 66 | Plus One | Easy | Accepted |
| 67 | Add Binary | Easy | Accepted |
| 68 | Text Justification | Hard | Accepted |
| 69 | Sqrt(x) | Easy | Accepted |
| 70 | Climbing Stairs | Easy | Accepted |
| 71 | Simplify Path | Medium | Accepted |
| 72 | Edit Distance | Hard | Accepted |
| 73 | Set Matrix Zeroes | Medium | Accepted |
| 74 | Search a 2D Matrix | Medium | Accepted |
| 75 | Sort Colors | Medium | Accepted |
| 76 | Minimum Window Substring | Hard | Accepted |
| 77 | Combinations | Medium | Accepted |
| 78 | Subsets | Medium | Accepted |
| 79 | Word Search | Medium | Accepted |
| 80 | Remove Duplicates from Sorted Array II | Medium | Accepted |
| 81 | Search in Rotated Sorted Array II | Medium | Accepted |
| 82 | Remove Duplicates from Sorted List II | Medium | Accepted |
| 83 | Remove Duplicates from Sorted List | Easy | Accepted |
| 84 | Largest Rectangle in Histogram | Hard | Accepted |
| 85 | Maximal Rectangle | Hard | Accepted |
| 86 | Partition List | Medium | Accepted |
| 87 | Scramble String | Hard | Accepted |
| 88 | Merge Sorted Array | Easy | Accepted |
| 89 | Gray Code | Medium | Accepted |
| 90 | Subsets II | Medium | Accepted |
| 91 | Decode Ways | Medium | Accepted |
| 92 | Reverse Linked List II | Medium | Accepted |
| 93 | Restore IP Addresses | Medium | Accepted |
| 94 | Binary Tree Inorder Traversal | Medium | Accepted |
| 95 | Unique Binary Search Trees II | Medium | Accepted |
| 96 | Unique Binary Search Trees | Medium | Accepted |
| 97 | Interleaving String | Hard | |
| 98 | Validate Binary Search Tree | Medium | Accepted |
| 99 | Recover Binary Search Tree | Hard | Accepted |
| 100 | Same Tree | Easy | Accepted |
| 101 | Symmetric Tree | Easy | Accepted |
| 102 | Binary Tree Level Order Traversal | Medium | Accepted |
| 103 | Binary Tree Zigzag Level Order Traversal | Medium | Accepted |
| 104 | Maximum Depth of Binary Tree | Easy | Accepted |
| 105 | Construct Binary Tree from Preorder and Inorder Traversal | Medium | Accepted |
| 106 | Construct Binary Tree from Inorder and Postorder Traversal | Medium | Accepted |
| 107 | Binary Tree Level Order Traversal II | Easy | Accepted |
| 108 | Convert Sorted Array to Binary Search Tree | Easy | Accepted |
| 109 | Convert Sorted List to Binary Search Tree | Medium | Accepted |
| 110 | Balanced Binary Tree | Easy | Accepted |
| 111 | Minimum Depth of Binary Tree | Easy | Accepted |
| 112 | Path Sum | Easy | Accepted |
| 113 | Path Sum II | Medium | Accepted |
| 114 | Flatten Binary Tree to Linked List | Medium | Accepted |
| 115 | Distinct Subsequences | Hard | Accepted |
| 116 | Populating Next Right Pointers in Each Node | Medium | Accepted |
| 117 | Populating Next Right Pointers in Each Node II | Medium | Accepted |
| 118 | Pascal's Triangle | Easy | Accepted |
| 119 | Pascal's Triangle II | Easy | Accepted |
| 120 | Triangle | Medium | Accepted |
| 121 | Best Time to Buy and Sell Stock | Easy | Accepted |
| 122 | Best Time to Buy and Sell Stock II | Easy | Accepted |
| 123 | Best Time to Buy and Sell Stock III | Hard | Accepted |
| 124 | Binary Tree Maximum Path Sum | Hard | Accepted |
| 125 | Valid Palindrome | Easy | Accepted |
| 126 | Word Ladder II | Hard | |
| 127 | Word Ladder | Medium | Accepted |
| 128 | Longest Consecutive Sequence | Hard | Accepted |
| 129 | Sum Root to Leaf Numbers | Medium | Accepted |
| 130 | Surrounded Regions | Medium | Accepted |
| 131 | Palindrome Partitioning | Medium | Accepted |
| 132 | Palindrome Partitioning II | Hard | |
| 133 | Clone Graph | Medium | Accepted |
| 134 | Gas Station | Medium | Accepted |
| 135 | Candy | Hard | Accepted |
| 136 | Single Number | Easy | Accepted |
| 137 | Single Number II | Medium | |
| 138 | Copy List with Random Pointer | Medium | Accepted |
| 139 | Word Break | Medium | Accepted |
| 140 | Word Break II | Hard | Accepted |
| 141 | Linked List Cycle | Easy | Accepted |
| 142 | Linked List Cycle II | Medium | Accepted |
| 143 | Reorder List | Medium | Accepted |
| 144 | Binary Tree Preorder Traversal | Medium | Accepted |
| 145 | Binary Tree Postorder Traversal | Hard | Accepted |
| 146 | LRU Cache | Medium | Accepted |
| 147 | Insertion Sort List | Medium | Accepted |
| 148 | Sort List | Medium | Accepted |
| 149 | Max Points on a Line | Hard | |
| 150 | Evaluate Reverse Polish Notation | Medium | Accepted |
| 151 | Reverse Words in a String | Medium | Accepted |
| 152 | Maximum Product Subarray | Medium | Accepted |
| 153 | Find Minimum in Rotated Sorted Array | Medium | Accepted |
| 154 | Find Minimum in Rotated Sorted Array II | Hard | Accepted |
| 155 | Min Stack | Easy | Accepted |
| 156 | Binary Tree Upside Down | Medium | |
| 157 | Read N Characters Given Read4 | Easy | |
| 158 | Read N Characters Given Read4 II - Call multiple times | Hard | Accepted |
| 159 | Longest Substring with At Most Two Distinct Characters | Hard | |
| 160 | Intersection of Two Linked Lists | Easy | Accepted |
| 161 | One Edit Distance | Medium | Accepted |
| 162 | Find Peak Element | Medium | Accepted |
| 163 | Missing Ranges | Medium | |
| 164 | Maximum Gap | Hard | |
| 165 | Compare Version Numbers | Medium | Accepted |
| 166 | Fraction to Recurring Decimal | Medium | Accepted |
| 167 | Two Sum II - Input array is sorted | Easy | Accepted |
| 168 | Excel Sheet Column Title | Easy | Accepted |
| 169 | Majority Element | Easy | Accepted |
| 170 | Two Sum III - Data structure design | Easy | |
| 171 | Excel Sheet Column Number | Easy | Accepted |
| 172 | Factorial Trailing Zeroes | Easy | Accepted |
| 173 | Binary Search Tree Iterator | Medium | Accepted |
| 174 | Dungeon Game | Hard | Accepted |
| 179 | Largest Number | Medium | Accepted |
| 186 | Reverse Words in a String II | Medium | |
| 187 | Repeated DNA Sequences | Medium | Accepted |
| 188 | Best Time to Buy and Sell Stock IV | Hard | |
| 189 | Rotate Array | Easy | Accepted |
| 190 | Reverse Bits | Easy | Accepted |
| 191 | Number of 1 Bits | Easy | Accepted |
| 198 | House Robber | Easy | Accepted |
| 199 | Binary Tree Right Side View | Medium | Accepted |
| 200 | Number of Islands | Medium | Accepted |
| 201 | Bitwise AND of Numbers Range | Medium | Accepted |
| 202 | Happy Number | Easy | Accepted |
| 203 | Remove Linked List Elements | Easy | Accepted |
| 204 | Count Primes | Easy | Accepted |
| 205 | Isomorphic Strings | Easy | Accepted |
| 206 | Reverse Linked List | Easy | Accepted |
| 207 | Course Schedule | Medium | Accepted |
| 208 | Implement Trie (Prefix Tree) | Medium | Accepted |
| 209 | Minimum Size Subarray Sum | Medium | Accepted |
| 210 | Course Schedule II | Medium | Accepted |
| 211 | Add and Search Word - Data structure design | Medium | Accepted |
| 212 | Word Search II | Hard | Accepted |
| 213 | House Robber II | Medium | Accepted |
| 214 | Shortest Palindrome | Hard | |
| 215 | Kth Largest Element in an Array | Medium | Accepted |
| 216 | Combination Sum III | Medium | Accepted |
| 217 | Contains Duplicate | Easy | Accepted |
| 218 | The Skyline Problem | Hard | Accepted |
| 219 | Contains Duplicate II | Easy | Accepted |
| 220 | Contains Duplicate III | Medium | Accepted |
| 221 | Maximal Square | Medium | Accepted |
| 222 | Count Complete Tree Nodes | Medium | Accepted |
| 223 | Rectangle Area | Medium | Accepted |
| 224 | Basic Calculator | Hard | Accepted |
| 225 | Implement Stack using Queues | Easy | Accepted |
| 226 | Invert Binary Tree | Easy | Accepted |
| 227 | Basic Calculator II | Medium | Accepted |
| 228 | Summary Ranges | Medium | Accepted |
| 229 | Majority Element II | Medium | Accepted |
| 230 | Kth Smallest Element in a BST | Medium | Accepted |
| 231 | Power of Two | Easy | Accepted |
| 232 | Implement Queue using Stacks | Easy | Accepted |
| 233 | Number of Digit One | Hard | |
| 234 | Palindrome Linked List | Easy | Accepted |
| 235 | Lowest Common Ancestor of a Binary Search Tree | Easy | Accepted |
| 236 | Lowest Common Ancestor of a Binary Tree | Medium | Accepted |
| 237 | Delete Node in a Linked List | Easy | Accepted |
| 238 | Product of Array Except Self | Medium | Accepted |
| 239 | Sliding Window Maximum | Hard | Accepted |
| 240 | Search a 2D Matrix II | Medium | Accepted |
| 241 | Different Ways to Add Parentheses | Medium | Accepted |
| 242 | Valid Anagram | Easy | Accepted |
| 243 | Shortest Word Distance | Easy | |
| 244 | Shortest Word Distance II | Medium | |
| 245 | Shortest Word Distance III | Medium | |
| 246 | Strobogrammatic Number | Easy | |
| 247 | Strobogrammatic Number II | Medium | |
| 248 | Strobogrammatic Number III | Hard | |
| 249 | Group Shifted Strings | Medium | |
| 250 | Count Univalue Subtrees | Medium | |
| 251 | Flatten 2D Vector | Medium | Accepted |
| 252 | Meeting Rooms | Easy | |
| 253 | Meeting Rooms II | Medium | Accepted |
| 254 | Factor Combinations | Medium | |
| 255 | Verify Preorder Sequence in Binary Search Tree | Medium | Accepted |
| 256 | Paint House | Easy | |
| 257 | Binary Tree Paths | Easy | Accepted |
| 258 | Add Digits | Easy | Accepted |
| 259 | 3Sum Smaller | Medium | |
| 260 | Single Number III | Medium | |
| 261 | Graph Valid Tree | Medium | |
| 263 | Ugly Number | Easy | Accepted |
| 264 | Ugly Number II | Medium | Accepted |
| 265 | Paint House II | Hard | |
| 266 | Palindrome Permutation | Easy | |
| 267 | Palindrome Permutation II | Medium | Accepted |
| 268 | Missing Number | Easy | Accepted |
| 269 | Alien Dictionary | Hard | Accepted |
| 270 | Closest Binary Search Tree Value | Easy | |
| 271 | Encode and Decode Strings | Medium | |
| 272 | Closest Binary Search Tree Value II | Hard | |
| 273 | Integer to English Words | Hard | Accepted |
| 274 | H-Index | Medium | Accepted |
| 275 | H-Index II | Medium | Accepted |
| 276 | Paint Fence | Easy | |
| 277 | Find the Celebrity | Medium | |
| 278 | First Bad Version | Easy | Accepted |
| 279 | Perfect Squares | Medium | Accepted |
| 280 | Wiggle Sort | Medium | |
| 281 | Zigzag Iterator | Medium | |
| 282 | Expression Add Operators | Hard | Accepted |
| 283 | Move Zeroes | Easy | Accepted |
| 284 | Peeking Iterator | Medium | Accepted |
| 285 | Inorder Successor in BST | Medium | |
| 286 | Walls and Gates | Medium | |
| 287 | Find the Duplicate Number | Medium | Accepted |
| 288 | Unique Word Abbreviation | Medium | |
| 289 | Game of Life | Medium | Accepted |
| 290 | Word Pattern | Easy | Accepted |
| 291 | Word Pattern II | Hard | |
| 292 | Nim Game | Easy | Accepted |
| 293 | Flip Game | Easy | |
| 294 | Flip Game II | Medium | |
| 295 | Find Median from Data Stream | Hard | Accepted |
| 296 | Best Meeting Point | Hard | |
| 297 | Serialize and Deserialize Binary Tree | Hard | Accepted |
| 298 | Binary Tree Longest Consecutive Sequence | Medium | |
| 299 | Bulls and Cows | Easy | Accepted |
| 300 | Longest Increasing Subsequence | Medium | Accepted |
| 301 | Remove Invalid Parentheses | Hard | Accepted |
| 302 | Smallest Rectangle Enclosing Black Pixels | Hard | |
| 303 | Range Sum Query - Immutable | Easy | Accepted |
| 304 | Range Sum Query 2D - Immutable | Medium | Accepted |
| 305 | Number of Islands II | Hard | |
| 306 | Additive Number | Medium | Accepted |
| 307 | Range Sum Query - Mutable | Medium | Accepted |
| 308 | Range Sum Query 2D - Mutable | Hard | |
| 309 | Best Time to Buy and Sell Stock with Cooldown | Medium | Accepted |
| 310 | Minimum Height Trees | Medium | Accepted |
| 311 | Sparse Matrix Multiplication | Medium | |
| 312 | Burst Balloons | Hard | Accepted |
| 313 | Super Ugly Number | Medium | Accepted |
| 314 | Binary Tree Vertical Order Traversal | Medium | |
| 315 | Count of Smaller Numbers After Self | Hard | Accepted |
| 316 | Remove Duplicate Letters | Hard | Accepted |
| 317 | Shortest Distance from All Buildings | Hard | |
| 318 | Maximum Product of Word Lengths | Medium | Accepted |
| 319 | Bulb Switcher | Medium | Accepted |
| 320 | Generalized Abbreviation | Medium | |
| 321 | Create Maximum Number | Hard | |
| 322 | Coin Change | Medium | Accepted |
| 323 | Number of Connected Components in an Undirected Graph | Medium | |
| 324 | Wiggle Sort II | Medium | Accepted |
| 325 | Maximum Size Subarray Sum Equals k | Medium | |
| 326 | Power of Three | Easy | Accepted |
| 327 | Count of Range Sum | Hard | |
| 328 | Odd Even Linked List | Medium | Accepted |
| 329 | Longest Increasing Path in a Matrix | Hard | Accepted |
| 330 | Patching Array | Hard | Accepted |
| 331 | Verify Preorder Serialization of a Binary Tree | Medium | Accepted |
| 332 | Reconstruct Itinerary | Medium | Accepted |
| 333 | Largest BST Subtree | Medium | |
| 334 | Increasing Triplet Subsequence | Medium | Accepted |
| 335 | Self Crossing | Hard | |
| 336 | Palindrome Pairs | Hard | Accepted |
| 337 | House Robber III | Medium | Accepted |
| 338 | Counting Bits | Medium | Accepted |
| 339 | Nested List Weight Sum | Easy | |
| 340 | Longest Substring with At Most K Distinct Characters | Hard | |
| 341 | Flatten Nested List Iterator | Medium | Accepted |
| 342 | Power of Four | Easy | Accepted |
| 343 | Integer Break | Medium | |
| 344 | Reverse String | Easy | Accepted |
| 345 | Reverse Vowels of a String | Easy | Accepted |
| 346 | Moving Average from Data Stream | Easy | |
| 347 | Top K Frequent Elements | Medium | Accepted |
| 348 | Design Tic-Tac-Toe | Medium | |
| 349 | Intersection of Two Arrays | Easy | Accepted |
| 350 | Intersection of Two Arrays II | Easy | Accepted |
| 351 | Android Unlock Patterns | Medium | |
| 352 | Data Stream as Disjoint Intervals | Hard | Accepted |
| 353 | Design Snake Game | Medium | |
| 354 | Russian Doll Envelopes | Hard | Accepted |
| 355 | Design Twitter | Medium | Accepted |
| 356 | Line Reflection | Medium | |
| 357 | Count Numbers with Unique Digits | Medium | Accepted |
| 358 | Rearrange String k Distance Apart | Hard | |
| 359 | Logger Rate Limiter | Easy | Accepted |
| 360 | Sort Transformed Array | Medium | |
| 361 | Bomb Enemy | Medium | Accepted |
| 362 | Design Hit Counter | Medium | |
| 363 | Max Sum of Rectangle No Larger Than K | Hard | Accepted |
| 364 | Nested List Weight Sum II | Medium | |
| 365 | Water and Jug Problem | Medium | |
| 366 | Find Leaves of Binary Tree | Medium | |
| 367 | Valid Perfect Square | Easy | Accepted |
| 368 | Largest Divisible Subset | Medium | Accepted |
| 369 | Plus One Linked List | Medium | |
| 370 | Range Addition | Medium | |
| 371 | Sum of Two Integers | Easy | Accepted |
| 372 | Super Pow | Medium | |
| 373 | Find K Pairs with Smallest Sums | Medium | Accepted |
| 374 | Guess Number Higher or Lower | Easy | Accepted |
| 375 | Guess Number Higher or Lower II | Medium | Accepted |
| 376 | Wiggle Subsequence | Medium | Accepted |
| 377 | Combination Sum IV | Medium | Accepted |
| 378 | Kth Smallest Element in a Sorted Matrix | Medium | Accepted |
| 379 | Design Phone Directory | Medium | |
| 380 | Insert Delete GetRandom O(1) | Medium | Accepted |
| 381 | Insert Delete GetRandom O(1) - Duplicates allowed | Hard | Accepted |
| 382 | Linked List Random Node | Medium | |
| 383 | Ransom Note | Easy | Accepted |
| 384 | Shuffle an Array | Medium | Accepted |
| 385 | Mini Parser | Medium | |
| 386 | Lexicographical Numbers | Medium | Accepted |
| 387 | First Unique Character in a String | Easy | Accepted |
| 388 | Longest Absolute File Path | Medium | Accepted |
| 389 | Find the Difference | Easy | Accepted |
| 390 | Elimination Game | Medium | Accepted |
| 391 | Perfect Rectangle | Hard | Accepted |
| 392 | Is Subsequence | Easy | Accepted |
| 393 | UTF-8 Validation | Medium | |
| 394 | Decode String | Medium | Accepted |
| 395 | Longest Substring with At Least K Repeating Characters | Medium | Accepted |
| 396 | Rotate Function | Medium | Accepted |
| 397 | Integer Replacement | Medium | Accepted |
| 398 | Random Pick Index | Medium | Accepted |
| 399 | Evaluate Division | Medium | Accepted |
| 400 | Nth Digit | Medium | Accepted |
| 401 | Binary Watch | Easy | Accepted |
| 402 | Remove K Digits | Medium | Accepted |
| 403 | Frog Jump | Hard | Accepted |
| 404 | Sum of Left Leaves | Easy | Accepted |
| 405 | Convert a Number to Hexadecimal | Easy | Accepted |
| 406 | Queue Reconstruction by Height | Medium | Accepted |
| 407 | Trapping Rain Water II | Hard | |
| 408 | Valid Word Abbreviation | Easy | |
| 409 | Longest Palindrome | Easy | Accepted |
| 410 | Split Array Largest Sum | Hard | |
| 411 | Minimum Unique Word Abbreviation | Hard | |
| 412 | Fizz Buzz | Easy | Accepted |
| 413 | Arithmetic Slices | Medium | Accepted |
| 414 | Third Maximum Number | Easy | Accepted |
| 415 | Add Strings | Easy | Accepted |
| 416 | Partition Equal Subset Sum | Medium | Accepted |
| 417 | Pacific Atlantic Water Flow | Medium | Accepted |
| 418 | Sentence Screen Fitting | Medium | |
| 419 | Battleships in a Board | Medium | Accepted |
| 420 | Strong Password Checker | Hard | |
| 421 | Maximum XOR of Two Numbers in an Array | Medium | |
| 422 | Valid Word Square | Easy | |
| 423 | Reconstruct Original Digits from English | Medium | Accepted |
| 424 | Longest Repeating Character Replacement | Medium | Accepted |
| 425 | Word Squares | Hard | |
| 426 | Convert Binary Search Tree to Sorted Doubly Linked List | Medium | |
| 427 | Construct Quad Tree | Medium | Accepted |
| 428 | Serialize and Deserialize N-ary Tree | Hard | |
| 429 | N-ary Tree Level Order Traversal | Medium | Accepted |
| 430 | Flatten a Multilevel Doubly Linked List | Medium | Accepted |
| 431 | Encode N-ary Tree to Binary Tree | Hard | |
| 432 | All O`one Data Structure | Hard | Accepted |
| 433 | Minimum Genetic Mutation | Medium | Accepted |
| 434 | Number of Segments in a String | Easy | Accepted |
| 435 | Non-overlapping Intervals | Medium | Accepted |
| 436 | Find Right Interval | Medium | Accepted |
| 437 | Path Sum III | Easy | Accepted |
| 438 | Find All Anagrams in a String | Medium | Accepted |
| 439 | Ternary Expression Parser | Medium | |
| 440 | K-th Smallest in Lexicographical Order | Hard | Accepted |
| 441 | Arranging Coins | Easy | Accepted |
| 442 | Find All Duplicates in an Array | Medium | Accepted |
| 443 | String Compression | Easy | Accepted |
| 444 | Sequence Reconstruction | Medium | |
| 445 | Add Two Numbers II | Medium | Accepted |
| 446 | Arithmetic Slices II - Subsequence | Hard | |
| 447 | Number of Boomerangs | Easy | |
| 448 | Find All Numbers Disappeared in an Array | Easy | Accepted |
| 449 | Serialize and Deserialize BST | Medium | |
| 450 | Delete Node in a BST | Medium | |
| 451 | Sort Characters By Frequency | Medium | |
| 452 | Minimum Number of Arrows to Burst Balloons | Medium | |
| 453 | Minimum Moves to Equal Array Elements | Easy | |
| 454 | 4Sum II | Medium | Accepted |
| 455 | Assign Cookies | Easy | |
| 456 | 132 Pattern | Medium | |
| 457 | Circular Array Loop | Medium | Accepted |
| 458 | Poor Pigs | Hard | |
| 459 | Repeated Substring Pattern | Easy | |
| 460 | LFU Cache | Hard | |
| 461 | Hamming Distance | Easy | Accepted |
| 462 | Minimum Moves to Equal Array Elements II | Medium | |
| 463 | Island Perimeter | Easy | Accepted |
| 464 | Can I Win | Medium | |
| 465 | Optimal Account Balancing | Hard | Accepted |
| 466 | Count The Repetitions | Hard | |
| 467 | Unique Substrings in Wraparound String | Medium | |
| 468 | Validate IP Address | Medium | |
| 469 | Convex Polygon | Medium | |
| 470 | Implement Rand10() Using Rand7() | Medium | |
| 471 | Encode String with Shortest Length | Hard | |
| 472 | Concatenated Words | Hard | |
| 473 | Matchsticks to Square | Medium | |
| 474 | Ones and Zeroes | Medium | |
| 475 | Heaters | Easy | |
| 476 | Number Complement | Easy | |
| 477 | Total Hamming Distance | Medium | Accepted |
| 478 | Generate Random Point in a Circle | Medium | |
| 479 | Largest Palindrome Product | Hard | |
| 480 | Sliding Window Median | Hard | |
| 481 | Magical String | Medium | |
| 482 | License Key Formatting | Easy | Accepted |
| 483 | Smallest Good Base | Hard | |
| 484 | Find Permutation | Medium | |
| 485 | Max Consecutive Ones | Easy | |
| 486 | Predict the Winner | Medium | |
| 487 | Max Consecutive Ones II | Medium | |
| 488 | Zuma Game | Hard | |
| 489 | Robot Room Cleaner | Hard | |
| 490 | The Maze | Medium | |
| 491 | Increasing Subsequences | Medium | Accepted |
| 492 | Construct the Rectangle | Easy | |
| 493 | Reverse Pairs | Hard | |
| 494 | Target Sum | Medium | Accepted |
| 495 | Teemo Attacking | Medium | |
| 496 | Next Greater Element I | Easy | |
| 497 | Random Point in Non-overlapping Rectangles | Medium | |
| 498 | Diagonal Traverse | Medium | |
| 499 | The Maze III | Hard | |
| 500 | Keyboard Row | Easy | |
| 501 | Find Mode in Binary Search Tree | Easy | |
| 502 | IPO | Hard | |
| 503 | Next Greater Element II | Medium | |
| 504 | Base 7 | Easy | |
| 505 | The Maze II | Medium | |
| 506 | Relative Ranks | Easy | |
| 507 | Perfect Number | Easy | |
| 508 | Most Frequent Subtree Sum | Medium | |
| 509 | Fibonacci Number | Easy | |
| 510 | Inorder Successor in BST II | Medium | |
| 513 | Find Bottom Left Tree Value | Medium | |
| 514 | Freedom Trail | Hard | |
| 515 | Find Largest Value in Each Tree Row | Medium | |
| 516 | Longest Palindromic Subsequence | Medium | Accepted |
| 517 | Super Washing Machines | Hard | |
| 518 | Coin Change 2 | Medium | |
| 519 | Random Flip Matrix | Medium | |
| 520 | Detect Capital | Easy | |
| 521 | Longest Uncommon Subsequence I | Easy | |
| 522 | Longest Uncommon Subsequence II | Medium | |
| 523 | Continuous Subarray Sum | Medium | Accepted |
| 524 | Longest Word in Dictionary through Deleting | Medium | Accepted |
| 525 | Contiguous Array | Medium | |
| 526 | Beautiful Arrangement | Medium | |
| 527 | Word Abbreviation | Hard | |
| 528 | Random Pick with Weight | Medium | Accepted |
| 529 | Minesweeper | Medium | Accepted |
| 530 | Minimum Absolute Difference in BST | Easy | |
| 531 | Lonely Pixel I | Medium | |
| 532 | K-diff Pairs in an Array | Easy | Accepted |
| 533 | Lonely Pixel II | Medium | |
| 535 | Encode and Decode TinyURL | Medium | Accepted |
| 536 | Construct Binary Tree from String | Medium | |
| 537 | Complex Number Multiplication | Medium | |
| 538 | Convert BST to Greater Tree | Easy | Accepted |
| 539 | Minimum Time Difference | Medium | |
| 540 | Single Element in a Sorted Array | Medium | |
| 541 | Reverse String II | Easy | |
| 542 | 01 Matrix | Medium | |
| 543 | Diameter of Binary Tree | Easy | Accepted |
| 544 | Output Contest Matches | Medium | |
| 545 | Boundary of Binary Tree | Medium | |
| 546 | Remove Boxes | Hard | |
| 547 | Friend Circles | Medium | |
| 548 | Split Array with Equal Sum | Medium | |
| 549 | Binary Tree Longest Consecutive Sequence II | Medium | |
| 551 | Student Attendance Record I | Easy | Accepted |
| 552 | Student Attendance Record II | Hard | |
| 553 | Optimal Division | Medium | |
| 554 | Brick Wall | Medium | Accepted |
| 555 | Split Concatenated Strings | Medium | |
| 556 | Next Greater Element III | Medium | |
| 557 | Reverse Words in a String III | Easy | |
| 558 | Quad Tree Intersection | Easy | |
| 559 | Maximum Depth of N-ary Tree | Easy | |
| 560 | Subarray Sum Equals K | Medium | Accepted |
| 561 | Array Partition I | Easy | |
| 562 | Longest Line of Consecutive One in Matrix | Medium | |
| 563 | Binary Tree Tilt | Easy | |
| 564 | Find the Closest Palindrome | Hard | |
| 565 | Array Nesting | Medium | |
| 566 | Reshape the Matrix | Easy | |
| 567 | Permutation in String | Medium | Accepted |
| 568 | Maximum Vacation Days | Hard | |
| 572 | Subtree of Another Tree | Easy | Accepted |
| 573 | Squirrel Simulation | Medium | |
| 575 | Distribute Candies | Easy | |
| 576 | Out of Boundary Paths | Medium | |
| 581 | Shortest Unsorted Continuous Subarray | Easy | Accepted |
| 582 | Kill Process | Medium | |
| 583 | Delete Operation for Two Strings | Medium | |
| 587 | Erect the Fence | Hard | |
| 588 | Design In-Memory File System | Hard | |
| 589 | N-ary Tree Preorder Traversal | Easy | |
| 590 | N-ary Tree Postorder Traversal | Easy | |
| 591 | Tag Validator | Hard | |
| 592 | Fraction Addition and Subtraction | Medium | |
| 593 | Valid Square | Medium | |
| 594 | Longest Harmonious Subsequence | Easy | |
| 598 | Range Addition II | Easy | |
| 599 | Minimum Index Sum of Two Lists | Easy | |
| 600 | Non-negative Integers without Consecutive Ones | Hard | |
| 604 | Design Compressed String Iterator | Easy | |
| 605 | Can Place Flowers | Easy | |
| 606 | Construct String from Binary Tree | Easy | |
| 609 | Find Duplicate File in System | Medium | |
| 611 | Valid Triangle Number | Medium | |
| 616 | Add Bold Tag in String | Medium | |
| 617 | Merge Two Binary Trees | Easy | Accepted |
| 621 | Task Scheduler | Medium | Accepted |
| 622 | Design Circular Queue | Medium | |
| 623 | Add One Row to Tree | Medium | |
| 624 | Maximum Distance in Arrays | Easy | |
| 625 | Minimum Factorization | Medium | |
| 628 | Maximum Product of Three Numbers | Easy | |
| 629 | K Inverse Pairs Array | Hard | |
| 630 | Course Schedule III | Hard | |
| 631 | Design Excel Sum Formula | Hard | |
| 632 | Smallest Range Covering Elements from K Lists | Hard | |
| 633 | Sum of Square Numbers | Easy | |
| 634 | Find the Derangement of An Array | Medium | |
| 635 | Design Log Storage System | Medium | |
| 636 | Exclusive Time of Functions | Medium | Accepted |
| 637 | Average of Levels in Binary Tree | Easy | Accepted |
| 638 | Shopping Offers | Medium | |
| 639 | Decode Ways II | Hard | |
| 640 | Solve the Equation | Medium | |
| 641 | Design Circular Deque | Medium | |
| 642 | Design Search Autocomplete System | Hard | |
| 643 | Maximum Average Subarray I | Easy | |
| 644 | Maximum Average Subarray II | Hard | |
| 645 | Set Mismatch | Easy | |
| 646 | Maximum Length of Pair Chain | Medium | |
| 647 | Palindromic Substrings | Medium | Accepted |
| 648 | Replace Words | Medium | |
| 649 | Dota2 Senate | Medium | |
| 650 | 2 Keys Keyboard | Medium | |
| 651 | 4 Keys Keyboard | Medium | |
| 652 | Find Duplicate Subtrees | Medium | |
| 653 | Two Sum IV - Input is a BST | Easy | |
| 654 | Maximum Binary Tree | Medium | Accepted |
| 655 | Print Binary Tree | Medium | Accepted |
| 656 | Coin Path | Hard | |
| 657 | Robot Return to Origin | Easy | |
| 658 | Find K Closest Elements | Medium | Accepted |
| 659 | Split Array into Consecutive Subsequences | Medium | |
| 660 | Remove 9 | Hard | |
| 661 | Image Smoother | Easy | |
| 662 | Maximum Width of Binary Tree | Medium | |
| 663 | Equal Tree Partition | Medium | |
| 664 | Strange Printer | Hard | |
| 665 | Non-decreasing Array | Easy | |
| 666 | Path Sum IV | Medium | |
| 667 | Beautiful Arrangement II | Medium | |
| 668 | Kth Smallest Number in Multiplication Table | Hard | Accepted |
| 669 | Trim a Binary Search Tree | Easy | |
| 670 | Maximum Swap | Medium | Accepted |
| 671 | Second Minimum Node In a Binary Tree | Easy | |
| 672 | Bulb Switcher II | Medium | |
| 673 | Number of Longest Increasing Subsequence | Medium | |
| 674 | Longest Continuous Increasing Subsequence | Easy | Accepted |
| 675 | Cut Off Trees for Golf Event | Hard | |
| 676 | Implement Magic Dictionary | Medium | |
| 677 | Map Sum Pairs | Medium | |
| 678 | Valid Parenthesis String | Medium | |
| 679 | 24 Game | Hard | |
| 680 | Valid Palindrome II | Easy | Accepted |
| 681 | Next Closest Time | Medium | |
| 682 | Baseball Game | Easy | |
| 683 | K Empty Slots | Hard | |
| 684 | Redundant Connection | Medium | Accepted |
| 685 | Redundant Connection II | Hard | Accepted |
| 686 | Repeated String Match | Easy | |
| 687 | Longest Univalue Path | Easy | |
| 688 | Knight Probability in Chessboard | Medium | |
| 689 | Maximum Sum of 3 Non-Overlapping Subarrays | Hard | Accepted |
| 690 | Employee Importance | Easy | |
| 691 | Stickers to Spell Word | Hard | |
| 692 | Top K Frequent Words | Medium | |
| 693 | Binary Number with Alternating Bits | Easy | |
| 694 | Number of Distinct Islands | Medium | |
| 695 | Max Area of Island | Medium | |
| 696 | Count Binary Substrings | Easy | |
| 697 | Degree of an Array | Easy | |
| 698 | Partition to K Equal Sum Subsets | Medium | |
| 699 | Falling Squares | Hard | |
| 700 | Search in a Binary Search Tree | Easy | |
| 701 | Insert into a Binary Search Tree | Medium | |
| 702 | Search in a Sorted Array of Unknown Size | Medium | |
| 703 | Kth Largest Element in a Stream | Easy | |
| 704 | Binary Search | Easy | Accepted |
| 705 | Design HashSet | Easy | |
| 706 | Design HashMap | Easy | |
| 707 | Design Linked List | Medium | Accepted |
| 708 | Insert into a Sorted Circular Linked List | Medium | |
| 709 | To Lower Case | Easy | |
| 710 | Random Pick with Blacklist | Hard | |
| 711 | Number of Distinct Islands II | Hard | |
| 712 | Minimum ASCII Delete Sum for Two Strings | Medium | |
| 713 | Subarray Product Less Than K | Medium | Accepted |
| 714 | Best Time to Buy and Sell Stock with Transaction Fee | Medium | Accepted |
| 715 | Range Module | Hard | |
| 716 | Max Stack | Easy | |
| 717 | 1-bit and 2-bit Characters | Easy | |
| 718 | Maximum Length of Repeated Subarray | Medium | |
| 719 | Find K-th Smallest Pair Distance | Hard | |
| 720 | Longest Word in Dictionary | Easy | |
| 721 | Accounts Merge | Medium | Accepted |
| 722 | Remove Comments | Medium | |
| 723 | Candy Crush | Medium | |
| 724 | Find Pivot Index | Easy | |
| 725 | Split Linked List in Parts | Medium | Accepted |
| 726 | Number of Atoms | Hard | |
| 727 | Minimum Window Subsequence | Hard | |
| 728 | Self Dividing Numbers | Easy | |
| 729 | My Calendar I | Medium | |
| 730 | Count Different Palindromic Subsequences | Hard | |
| 731 | My Calendar II | Medium | |
| 732 | My Calendar III | Hard | |
| 733 | Flood Fill | Easy | |
| 734 | Sentence Similarity | Easy | |
| 735 | Asteroid Collision | Medium | |
| 736 | Parse Lisp Expression | Hard | |
| 737 | Sentence Similarity II | Medium | |
| 738 | Monotone Increasing Digits | Medium | |
| 739 | Daily Temperatures | Medium | Accepted |
| 740 | Delete and Earn | Medium | |
| 741 | Cherry Pickup | Hard | |
| 742 | Closest Leaf in a Binary Tree | Medium | |
| 743 | Network Delay Time | Medium | Accepted |
| 744 | Find Smallest Letter Greater Than Target | Easy | |
| 745 | Prefix and Suffix Search | Hard | |
| 746 | Min Cost Climbing Stairs | Easy | |
| 747 | Largest Number At Least Twice of Others | Easy | Accepted |
| 748 | Shortest Completing Word | Easy | |
| 749 | Contain Virus | Hard | |
| 750 | Number Of Corner Rectangles | Medium | |
| 751 | IP to CIDR | Easy | |
| 752 | Open the Lock | Medium | |
| 753 | Cracking the Safe | Hard | |
| 754 | Reach a Number | Easy | |
| 755 | Pour Water | Medium | Accepted |
| 756 | Pyramid Transition Matrix | Medium | |
| 757 | Set Intersection Size At Least Two | Hard | |
| 758 | Bold Words in String | Easy | |
| 759 | Employee Free Time | Hard | |
| 760 | Find Anagram Mappings | Easy | |
| 761 | Special Binary String | Hard | |
| 762 | Prime Number of Set Bits in Binary Representation | Easy | |
| 763 | Partition Labels | Medium | Accepted |
| 764 | Largest Plus Sign | Medium | |
| 765 | Couples Holding Hands | Hard | |
| 766 | Toeplitz Matrix | Easy | |
| 767 | Reorganize String | Medium | |
| 768 | Max Chunks To Make Sorted II | Hard | |
| 769 | Max Chunks To Make Sorted | Medium | |
| 770 | Basic Calculator IV | Hard | |
| 771 | Jewels and Stones | Easy | Accepted |
| 772 | Basic Calculator III | Hard | |
| 773 | Sliding Puzzle | Hard | Accepted |
| 774 | Minimize Max Distance to Gas Station | Hard | |
| 775 | Global and Local Inversions | Medium | |
| 776 | Split BST | Medium | |
| 777 | Swap Adjacent in LR String | Medium | |
| 778 | Swim in Rising Water | Hard | |
| 779 | K-th Symbol in Grammar | Medium | |
| 780 | Reaching Points | Hard | Accepted |
| 781 | Rabbits in Forest | Medium | |
| 782 | Transform to Chessboard | Hard | |
| 783 | Minimum Distance Between BST Nodes | Easy | |
| 784 | Letter Case Permutation | Easy | Accepted |
| 785 | Is Graph Bipartite? | Medium | Accepted |
| 786 | K-th Smallest Prime Fraction | Hard | |
| 787 | Cheapest Flights Within K Stops | Medium | Accepted |
| 788 | Rotated Digits | Easy | |
| 789 | Escape The Ghosts | Medium | |
| 790 | Domino and Tromino Tiling | Medium | |
| 791 | Custom Sort String | Medium | |
| 792 | Number of Matching Subsequences | Medium | |
| 793 | Preimage Size of Factorial Zeroes Function | Hard | |
| 794 | Valid Tic-Tac-Toe State | Medium | |
| 795 | Number of Subarrays with Bounded Maximum | Medium | |
| 796 | Rotate String | Easy | |
| 797 | All Paths From Source to Target | Medium | |
| 798 | Smallest Rotation with Highest Score | Hard | |
| 799 | Champagne Tower | Medium | |
| 800 | Similar RGB Color | Easy | Accepted |
| 801 | Minimum Swaps To Make Sequences Increasing | Medium | Accepted |
| 802 | Find Eventual Safe States | Medium | Accepted |
| 803 | Bricks Falling When Hit | Hard | |
| 804 | Unique Morse Code Words | Easy | Accepted |
| 805 | Split Array With Same Average | Hard | |
| 806 | Number of Lines To Write String | Easy | Accepted |
| 807 | Max Increase to Keep City Skyline | Medium | |
| 808 | Soup Servings | Medium | |
| 809 | Expressive Words | Medium | Accepted |
| 810 | Chalkboard XOR Game | Hard | |
| 811 | Subdomain Visit Count | Easy | |
| 812 | Largest Triangle Area | Easy | |
| 813 | Largest Sum of Averages | Medium | |
| 814 | Binary Tree Pruning | Medium | |
| 815 | Bus Routes | Hard | |
| 816 | Ambiguous Coordinates | Medium | |
| 817 | Linked List Components | Medium | Accepted |
| 818 | Race Car | Hard | |
| 819 | Most Common Word | Easy | Accepted |
| 820 | Short Encoding of Words | Medium | |
| 821 | Shortest Distance to a Character | Easy | |
| 822 | Card Flipping Game | Medium | |
| 823 | Binary Trees With Factors | Medium | |
| 824 | Goat Latin | Easy | |
| 825 | Friends Of Appropriate Ages | Medium | Accepted |
| 826 | Most Profit Assigning Work | Medium | Accepted |
| 827 | Making A Large Island | Hard | |
| 828 | Unique Letter String | Hard | |
| 829 | Consecutive Numbers Sum | Hard | |
| 830 | Positions of Large Groups | Easy | |
| 831 | Masking Personal Information | Medium | |
| 832 | Flipping an Image | Easy | |
| 833 | Find And Replace in String | Medium | |
| 834 | Sum of Distances in Tree | Hard | |
| 835 | Image Overlap | Medium | |
| 836 | Rectangle Overlap | Easy | |
| 837 | New 21 Game | Medium | |
| 838 | Push Dominoes | Medium | Accepted |
| 839 | Similar String Groups | Hard | |
| 840 | Magic Squares In Grid | Easy | |
| 841 | Keys and Rooms | Medium | |
| 842 | Split Array into Fibonacci Sequence | Medium | |
| 843 | Guess the Word | Hard | |
| 844 | Backspace String Compare | Easy | Accepted |
| 845 | Longest Mountain in Array | Medium | Accepted |
| 846 | Hand of Straights | Medium | |
| 847 | Shortest Path Visiting All Nodes | Hard | |
| 848 | Shifting Letters | Medium | |
| 849 | Maximize Distance to Closest Person | Easy | |
| 850 | Rectangle Area II | Hard | |
| 851 | Loud and Rich | Medium | |
| 852 | Peak Index in a Mountain Array | Easy | Accepted |
| 853 | Car Fleet | Medium | |
| 854 | K-Similar Strings | Hard | |
| 855 | Exam Room | Medium | |
| 856 | Score of Parentheses | Medium | |
| 857 | Minimum Cost to Hire K Workers | Hard | |
| 858 | Mirror Reflection | Medium | |
| 859 | Buddy Strings | Easy | |
| 860 | Lemonade Change | Easy | |
| 861 | Score After Flipping Matrix | Medium | |
| 862 | Shortest Subarray with Sum at Least K | Hard | |
| 863 | All Nodes Distance K in Binary Tree | Medium | Accepted |
| 864 | Shortest Path to Get All Keys | Hard | |
| 865 | Smallest Subtree with all the Deepest Nodes | Medium | |
| 866 | Prime Palindrome | Medium | |
| 867 | Transpose Matrix | Easy | |
| 868 | Binary Gap | Easy | |
| 869 | Reordered Power of 2 | Medium | |
| 870 | Advantage Shuffle | Medium | |
| 871 | Minimum Number of Refueling Stops | Hard | |
| 872 | Leaf-Similar Trees | Easy | |
| 873 | Length of Longest Fibonacci Subsequence | Medium | |
| 874 | Walking Robot Simulation | Easy | |
| 875 | Koko Eating Bananas | Medium | |
| 876 | Middle of the Linked List | Easy | Accepted |
| 877 | Stone Game | Medium | |
| 878 | Nth Magical Number | Hard | |
| 879 | Profitable Schemes | Hard | |
| 880 | Decoded String at Index | Medium | |
| 881 | Boats to Save People | Medium | Accepted |
| 882 | Reachable Nodes In Subdivided Graph | Hard | |
| 883 | Projection Area of 3D Shapes | Easy | |
| 884 | Uncommon Words from Two Sentences | Easy | |
| 885 | Spiral Matrix III | Medium | |
| 886 | Possible Bipartition | Medium | |
| 887 | Super Egg Drop | Hard | |
| 888 | Fair Candy Swap | Easy | |
| 889 | Construct Binary Tree from Preorder and Postorder Traversal | Medium | |
| 890 | Find and Replace Pattern | Medium | |
| 891 | Sum of Subsequence Widths | Hard | |
| 892 | Surface Area of 3D Shapes | Easy | |
| 893 | Groups of Special-Equivalent Strings | Easy | |
| 894 | All Possible Full Binary Trees | Medium | |
| 895 | Maximum Frequency Stack | Hard | |
| 896 | Monotonic Array | Easy | Accepted |
| 897 | Increasing Order Search Tree | Easy | |
| 898 | Bitwise ORs of Subarrays | Medium | |
| 899 | Orderly Queue | Hard | |
| 900 | RLE Iterator | Medium | |
| 901 | Online Stock Span | Medium | |
| 902 | Numbers At Most N Given Digit Set | Hard | |
| 903 | Valid Permutations for DI Sequence | Hard | |
| 904 | Fruit Into Baskets | Medium | Accepted |
| 905 | Sort Array By Parity | Easy | |
| 906 | Super Palindromes | Hard | |
| 907 | Sum of Subarray Minimums | Medium | |
| 908 | Smallest Range I | Easy | |
| 909 | Snakes and Ladders | Medium | |
| 910 | Smallest Range II | Medium | |
| 911 | Online Election | Medium | |
| 912 | Sort an Array | Medium | |
| 913 | Cat and Mouse | Hard | |
| 914 | X of a Kind in a Deck of Cards | Easy | |
| 915 | Partition Array into Disjoint Intervals | Medium | |
| 916 | Word Subsets | Medium | Accepted |
| 917 | Reverse Only Letters | Easy | |
| 918 | Maximum Sum Circular Subarray | Medium | |
| 919 | Complete Binary Tree Inserter | Medium | |
| 920 | Number of Music Playlists | Hard | |
| 921 | Minimum Add to Make Parentheses Valid | Medium | |
| 922 | Sort Array By Parity II | Easy | |
| 923 | 3Sum With Multiplicity | Medium | Accepted |
| 924 | Minimize Malware Spread | Hard | |
| 925 | Long Pressed Name | Easy | Accepted |
| 926 | Flip String to Monotone Increasing | Medium | |
| 927 | Three Equal Parts | Hard | |
| 928 | Minimize Malware Spread II | Hard | |
| 929 | Unique Email Addresses | Easy | |
| 930 | Binary Subarrays With Sum | Medium | Accepted |
| 931 | Minimum Falling Path Sum | Medium | |
| 932 | Beautiful Array | Medium | |
| 933 | Number of Recent Calls | Easy | |
| 934 | Shortest Bridge | Medium | |
| 935 | Knight Dialer | Medium | |
| 936 | Stamping The Sequence | Hard | |
| 937 | Reorder Data in Log Files | Easy | |
| 938 | Range Sum of BST | Easy | |
| 939 | Minimum Area Rectangle | Medium | |
| 940 | Distinct Subsequences II | Hard | |
| 941 | Valid Mountain Array | Easy | |
| 942 | DI String Match | Easy | |
| 943 | Find the Shortest Superstring | Hard | |
| 944 | Delete Columns to Make Sorted | Easy | |
| 945 | Minimum Increment to Make Array Unique | Medium | |
| 946 | Validate Stack Sequences | Medium | |
| 947 | Most Stones Removed with Same Row or Column | Medium | |
| 948 | Bag of Tokens | Medium | |
| 949 | Largest Time for Given Digits | Easy | |
| 950 | Reveal Cards In Increasing Order | Medium | |
| 951 | Flip Equivalent Binary Trees | Medium | |
| 952 | Largest Component Size by Common Factor | Hard | |
| 953 | Verifying an Alien Dictionary | Easy | Accepted |
| 954 | Array of Doubled Pairs | Medium | |
| 955 | Delete Columns to Make Sorted II | Medium | |
| 956 | Tallest Billboard | Hard | |
| 957 | Prison Cells After N Days | Medium | |
| 958 | Check Completeness of a Binary Tree | Medium | |
| 959 | Regions Cut By Slashes | Medium | |
| 960 | Delete Columns to Make Sorted III | Hard | |
| 961 | N-Repeated Element in Size 2N Array | Easy | |
| 962 | Maximum Width Ramp | Medium | |
| 963 | Minimum Area Rectangle II | Medium | |
| 964 | Least Operators to Express Number | Hard | |
| 965 | Univalued Binary Tree | Easy | |
| 966 | Vowel Spellchecker | Medium | |
| 967 | Numbers With Same Consecutive Differences | Medium | |
| 968 | Binary Tree Cameras | Hard | |
| 969 | Pancake Sorting | Medium | |
| 970 | Powerful Integers | Easy | Accepted |
| 971 | Flip Binary Tree To Match Preorder Traversal | Medium | |
| 972 | Equal Rational Numbers | Hard | |
| 973 | K Closest Points to Origin | Medium | Accepted |
| 974 | Subarray Sums Divisible by K | Medium | |
| 975 | Odd Even Jump | Hard | |
| 976 | Largest Perimeter Triangle | Easy | |
| 977 | Squares of a Sorted Array | Easy | Accepted |
| 978 | Longest Turbulent Subarray | Medium | |
| 979 | Distribute Coins in Binary Tree | Medium | |
| 980 | Unique Paths III | Hard | Accepted |
| 981 | Time Based Key-Value Store | Medium | Accepted |
| 982 | Triples with Bitwise AND Equal To Zero | Hard | |
| 983 | Minimum Cost For Tickets | Medium | |
| 984 | String Without AAA or BBB | Medium | |
| 985 | Sum of Even Numbers After Queries | Easy | Accepted |
| 986 | Interval List Intersections | Medium | Accepted |
| 987 | Vertical Order Traversal of a Binary Tree | Medium | |
| 988 | Smallest String Starting From Leaf | Medium | Accepted |
| 989 | Add to Array-Form of Integer | Easy | |
| 990 | Satisfiability of Equality Equations | Medium | |
| 991 | Broken Calculator | Medium | |
| 992 | Subarrays with K Different Integers | Hard | |
| 993 | Cousins in Binary Tree | Easy | |
| 994 | Rotting Oranges | Easy | |
| 995 | Minimum Number of K Consecutive Bit Flips | Hard | |
| 996 | Number of Squareful Arrays | Hard | |
| 997 | Find the Town Judge | Easy | Accepted |
| 998 | Maximum Binary Tree II | Medium | Accepted |
| 999 | Available Captures for Rook | Easy | Accepted |
| 1000 | Minimum Cost to Merge Stones | Hard | |
| 1001 | Grid Illumination | Hard | Accepted |
| 1002 | Find Common Characters | Easy | Accepted |
| 1003 | Check If Word Is Valid After Substitutions | Medium | Accepted |
| 1004 | Max Consecutive Ones III | Medium | Accepted |
| 1005 | Maximize Sum Of Array After K Negations | Easy | Accepted |
| 1006 | Clumsy Factorial | Medium | Accepted |
| 1007 | Minimum Domino Rotations For Equal Row | Medium | Accepted |
| 1008 | Construct Binary Search Tree from Preorder Traversal | Medium | Accepted |
| 1009 | Complement of Base 10 Integer | Easy | |
| 1010 | Pairs of Songs With Total Durations Divisible by 60 | Easy | |
| 1011 | Capacity To Ship Packages Within D Days | Medium | |
| 1012 | Numbers With Repeated Digits | Hard | |
| 1013 | Partition Array Into Three Parts With Equal Sum | Easy | |
| 1014 | Best Sightseeing Pair | Medium | |
| 1015 | Smallest Integer Divisible by K | Medium | |
| 1016 | Binary String With Substrings Representing 1 To N | Medium | |
| 1017 | Convert to Base -2 | Medium | Accepted |
| 1018 | Binary Prefix Divisible By 5 | Easy | Accepted |
| 1019 | Next Greater Node In Linked List | Medium | Accepted |
| 1020 | Number of Enclaves | Medium | Accepted |
| 1021 | Remove Outermost Parentheses | Easy | |
| 1022 | Sum of Root To Leaf Binary Numbers | Easy | |
| 1023 | Camelcase Matching | Medium | |
| 1024 | Video Stitching | Medium | |
| 1025 | Divisor Game | Easy | Accepted |
| 1026 | Maximum Difference Between Node and Ancestor | Medium | Accepted |
| 1027 | Longest Arithmetic Sequence | Medium | Accepted |
| 1028 | Recover a Tree From Preorder Traversal | Hard | Accepted |
| 1029 | Two City Scheduling | Easy | |
| 1030 | Matrix Cells in Distance Order | Easy | |
| 1031 | Maximum Sum of Two Non-Overlapping Subarrays | Medium | |
| 1032 | Stream of Characters | Hard | |
| 1033 | Moving Stones Until Consecutive | Easy | |
| 1034 | Coloring A Border | Medium | |
| 1035 | Uncrossed Lines | Medium | |
| 1036 | Escape a Large Maze | Hard | |
| 1037 | Valid Boomerang | Easy | |
| 1038 | Binary Search Tree to Greater Sum Tree | Medium | |
| 1039 | Minimum Score Triangulation of Polygon | Medium | |
| 1040 | Moving Stones Until Consecutive II | Medium | |
| 1041 | Robot Bounded In Circle | Medium | Accepted |
| 1042 | Flower Planting With No Adjacent | Easy | Accepted |
| 1043 | Partition Array for Maximum Sum | Medium | Accepted |
| 1044 | Longest Duplicate Substring | Hard | |
| 1046 | Last Stone Weight | Easy | Accepted |
| 1047 | Remove All Adjacent Duplicates In String | Easy | Accepted |
| 1048 | Longest String Chain | Medium | Accepted |
| 1049 | Last Stone Weight II | Medium | |
| 1051 | Height Checker | Easy | |
| 1052 | Grumpy Bookstore Owner | Medium | |
| 1053 | Previous Permutation With One Swap | Medium | |
| 1054 | Distant Barcodes | Medium | |
| 1055 | Shortest Way to Form String | Medium | Accepted |
| 1056 | Confusing Number | Easy | |
| 1057 | Campus Bikes | Medium | Accepted |
| 1058 | Minimize Rounding Error to Meet Target | Medium | |
| 1059 | All Paths from Source Lead to Destination | Medium | |
| 1060 | Missing Element in Sorted Array | Medium | |
| 1061 | Lexicographically Smallest Equivalent String | Medium | |
| 1062 | Longest Repeating Substring | Medium | |
| 1063 | Number of Valid Subarrays | Hard | |
| 1064 | Fixed Point | Easy | |
| 1065 | Index Pairs of a String | Easy | |
| 1066 | Campus Bikes II | Medium | |
| 1067 | Digit Count in Range | Hard | |
| 1071 | Greatest Common Divisor of Strings | Easy | |
| 1072 | Flip Columns For Maximum Number of Equal Rows | Medium | |
| 1073 | Adding Two Negabinary Numbers | Medium | |
| 1074 | Number of Submatrices That Sum to Target | Hard | |
| 1078 | Occurrences After Bigram | Easy | Accepted |
| 1079 | Letter Tile Possibilities | Medium | Accepted |
| 1080 | Insufficient Nodes in Root to Leaf Paths | Medium | Accepted |
| 1081 | Smallest Subsequence of Distinct Characters | Medium | Accepted |
| 1085 | Sum of Digits in the Minimum Number | Easy | |
| 1086 | High Five | Easy | |
| 1087 | Brace Expansion | Medium | |
| 1088 | Confusing Number II | Hard | |
| 1089 | Duplicate Zeros | Easy | |
| 1090 | Largest Values From Labels | Medium | |
| 1091 | Shortest Path in Binary Matrix | Medium | |
| 1092 | Shortest Common Supersequence | Hard | |
| 1093 | Statistics from a Large Sample | Medium | Accepted |
| 1094 | Car Pooling | Medium | Accepted |
| 1095 | Find in Mountain Array | Hard | Accepted |
| 1096 | Brace Expansion II | Hard | |
| 1099 | Two Sum Less Than K | Easy | |
| 1100 | Find K-Length Substrings With No Repeated Characters | Medium | |
| 1101 | The Earliest Moment When Everyone Become Friends | Medium | |
| 1102 | Path With Maximum Minimum Value | Medium | |
| 1103 | Distribute Candies to People | Easy | |
| 1104 | Path In Zigzag Labelled Binary Tree | Medium | |
| 1105 | Filling Bookcase Shelves | Medium | |
| 1106 | Parsing A Boolean Expression | Hard | |
| 1108 | Defanging an IP Address | Easy | Accepted |
| 1109 | Corporate Flight Bookings | Medium | Accepted |
| 1110 | Delete Nodes And Return Forest | Medium | Accepted |
| 1111 | Maximum Nesting Depth of Two Valid Parentheses Strings | Medium | Accepted |
| 1118 | Number of Days in a Month | Easy | |
| 1119 | Remove Vowels from a String | Easy | |
| 1120 | Maximum Average Subtree | Medium | |
| 1121 | Divide Array Into Increasing Sequences | Hard | |
| 1122 | Relative Sort Array | Easy | |
| 1123 | Lowest Common Ancestor of Deepest Leaves | Medium | |
| 1124 | Longest Well-Performing Interval | Medium | |
| 1125 | Smallest Sufficient Team | Hard | |
| 1128 | Number of Equivalent Domino Pairs | Easy | Accepted |
| 1129 | Shortest Path with Alternating Colors | Medium | Accepted |
| 1130 | Minimum Cost Tree From Leaf Values | Medium | Accepted |
| 1131 | Maximum of Absolute Value Expression | Medium | Accepted |
| 1133 | Largest Unique Number | Easy | |
| 1134 | Armstrong Number | Easy | |
| 1135 | Connecting Cities With Minimum Cost | Medium | |
| 1136 | Parallel Courses | Hard | |
| 1137 | N-th Tribonacci Number | Easy | Accepted |
| 1138 | Alphabet Board Path | Medium | Accepted |
| 1139 | Largest 1-Bordered Square | Medium | Accepted |
| 1140 | Stone Game II | Medium | |
| 1143 | Longest Common Subsequence | Medium | |
| 1144 | Decrease Elements To Make Array Zigzag | Medium | |
| 1145 | Binary Tree Coloring Game | Medium | |
| 1146 | Snapshot Array | Medium | |
| 1147 | Longest Chunked Palindrome Decomposition | Hard | |
| 1150 | Check If a Number Is Majority Element in a Sorted Array | Easy | |
| 1151 | Minimum Swaps to Group All 1's Together | Medium | |
| 1152 | Analyze User Website Visit Pattern | Medium | |
| 1153 | String Transforms Into Another String | Hard | |
| 1154 | Day of the Year | Easy | |
| 1155 | Number of Dice Rolls With Target Sum | Medium | |
| 1156 | Swap For Longest Repeated Character Substring | Medium | |
| 1157 | Online Majority Element In Subarray | Hard | |
| 1160 | Find Words That Can Be Formed by Characters | Easy | |
| 1161 | Maximum Level Sum of a Binary Tree | Medium | |
| 1162 | As Far from Land as Possible | Medium | |
| 1163 | Last Substring in Lexicographical Order | Hard | |
| 1165 | Single-Row Keyboard | Easy | |
| 1166 | Design File System | Medium | |
| 1167 | Minimum Cost to Connect Sticks | Medium | |
| 1168 | Optimize Water Distribution in a Village | Hard | |
| 1169 | Invalid Transactions | Medium | |
| 1170 | Compare Strings by Frequency of the Smallest Character | Easy | Accepted |
| 1171 | Remove Zero Sum Consecutive Nodes from Linked List | Medium | |
| 1172 | Dinner Plate Stacks | Hard | |
| 1175 | Prime Arrangements | Easy | |
| 1176 | Diet Plan Performance | Easy | |
| 1177 | Can Make Palindrome from Substring | Medium | |
| 1178 | Number of Valid Words for Each Puzzle | Hard | |
| 1180 | Count Substrings with Only One Distinct Letter | Easy | |
| 1181 | Before and After Puzzle | Medium | |
| 1182 | Shortest Distance to Target Color | Medium | |
| 1183 | Maximum Number of Ones | Hard | |
| 1184 | Distance Between Bus Stops | Easy | |
| 1185 | Day of the Week | Easy | |
| 1186 | Maximum Subarray Sum with One Deletion | Medium | |
| 1187 | Make Array Strictly Increasing | Hard | |
| 1189 | Maximum Number of Balloons | Easy | |
| 1190 | Reverse Substrings Between Each Pair of Parentheses | Medium | |
| 1191 | K-Concatenation Maximum Sum | Medium | |
| 1192 | Critical Connections in a Network | Hard | |
| 1196 | How Many Apples Can You Put into the Basket | Easy | |
| 1197 | Minimum Knight Moves | Medium | |
| 1198 | Find Smallest Common Element in All Rows | Medium | |
| 1199 | Minimum Time to Build Blocks | Hard | |
| 1200 | Minimum Absolute Difference | Easy | Accepted |
| 1201 | Ugly Number III | Medium | |
| 1202 | Smallest String With Swaps | Medium | |
| 1203 | Sort Items by Groups Respecting Dependencies | Hard | |
| 1206 | Design Skiplist | Hard | |
| 1207 | Unique Number of Occurrences | Easy | |
| 1208 | Get Equal Substrings Within Budget | Medium | |
| 1209 | Remove All Adjacent Duplicates in String II | Medium | |
| 1210 | Minimum Moves to Reach Target with Rotations | Hard | |
| 1213 | Intersection of Three Sorted Arrays | Easy | |
| 1214 | Two Sum BSTs | Medium | |
| 1215 | Stepping Numbers | Medium | |
| 1216 | Valid Palindrome III | Hard | |
| 1217 | Play with Chips | Easy | |
| 1218 | Longest Arithmetic Subsequence of Given Difference | Medium | |
| 1219 | Path with Maximum Gold | Medium | |
| 1220 | Count Vowels Permutation | Hard | |
| 1221 | Split a String in Balanced Strings | Easy | |
| 1222 | Queens That Can Attack the King | Medium | |
| 1223 | Dice Roll Simulation | Medium | |
| 1224 | Maximum Equal Frequency | Hard | |
| 1227 | Airplane Seat Assignment Probability | Medium | |
| 1228 | Missing Number In Arithmetic Progression | Easy | |
| 1229 | Meeting Scheduler | Medium | |
| 1230 | Toss Strange Coins | Medium | |
| 1231 | Divide Chocolate | Hard | |
| 1232 | Check If It Is a Straight Line | Easy | |
| 1233 | Remove Sub-Folders from the Filesystem | Medium | |
| 1234 | Replace the Substring for Balanced String | Medium | |
| 1235 | Maximum Profit in Job Scheduling | Hard | |
| 1236 | Web Crawler | Medium | |
| 1237 | Find Positive Integer Solution for a Given Equation | Easy | |
| 1238 | Circular Permutation in Binary Representation | Medium | |
| 1239 | Maximum Length of a Concatenated String with Unique Characters | Medium | |
| 1240 | Tiling a Rectangle with the Fewest Squares | Hard | |
| 1243 | Array Transformation | Easy | |
| 1244 | Design A Leaderboard | Medium | |
| 1245 | Tree Diameter | Medium | |
| 1246 | Palindrome Removal | Hard | |
| 1247 | Minimum Swaps to Make Strings Equal | Medium | |
| 1248 | Count Number of Nice Subarrays | Medium | |
| 1249 | Minimum Remove to Make Valid Parentheses | Medium | |
| 1250 | Check If It Is a Good Array | Hard | |
| 1252 | Cells with Odd Values in a Matrix | Easy | |
| 1253 | Reconstruct a 2-Row Binary Matrix | Medium | |
| 1254 | Number of Closed Islands | Medium | |
| 1255 | Maximum Score Words Formed by Letters | Hard | |
| 1256 | Encode Number | Medium | |
| 1257 | Smallest Common Region | Medium | |
| 1258 | Synonymous Sentences | Medium | |
| 1259 | Handshakes That Don't Cross | Hard | |
| 1260 | Shift 2D Grid | Easy | Accepted |
| 1261 | Find Elements in a Contaminated Binary Tree | Medium | Accepted |
| 1262 | Greatest Sum Divisible by Three | Medium | Accepted |
| 1263 | Minimum Moves to Move a Box to Their Target Location | Hard | |
| 1265 | Print Immutable Linked List in Reverse | Medium | |
| 1266 | Minimum Time Visiting All Points | Easy | Accepted |
| 1267 | Count Servers that Communicate | Medium | Accepted |
| 1268 | Search Suggestions System | Medium | Accepted |
| 1269 | Number of Ways to Stay in the Same Place After Some Steps | Hard | Accepted |