| 242 | Valid Anagram | Easy | 1151 | hash-tablestringsorting |
| 252 | Meeting Rooms | Easy | 1163 | arraysorting |
| 253 | Meeting Rooms II | Medium | 1582 | arraytwo-pointersgreedy+3 |
| 256 | Paint House | Medium | — | arraydynamic-programming |
| 258 | Add Digits | Easy | — | mathsimulationnumber-theory |
| 260 | Single Number III | Medium | 1321 | arraybit-manipulation |
| 261 | Graph Valid Tree | Medium | 1620 | depth-first-searchbreadth-first-searchunion-find+1 |
| 263 | Ugly Number | Easy | — | math |
| 264 | Ugly Number II | Medium | 1559 | dynamic-programmingmathheap-priority-queue |
| 268 | Missing Number | Easy | 1114 | arrayhash-tablemath+2 |
| 269 | Alien Dictionary | Hard | 1930 | arraystringdepth-first-search+3 |
| 271 | Encode and Decode Strings | Medium | 1530 | arraystringdesign |
| 274 | H-Index | Medium | 1405 | arraysortingcounting-sort |
| 278 | First Bad Version | Easy | 1161 | binary-searchinteractive |
| 279 | Perfect Squares | Medium | 1529 | mathdynamic-programmingbreadth-first-search |
| 280 | Wiggle Sort | Medium | — | arraygreedysorting |
| 283 | Move Zeroes | Easy | 1108 | arraytwo-pointers |
| 286 | Walls and Gates | Medium | 1638 | arraybreadth-first-searchmatrix |
| 287 | Find the Duplicate Number | Medium | 1689 | arraytwo-pointersbinary-search+1 |
| 289 | Game of Life | Medium | 1529 | arraymatrixsimulation |
| 290 | Word Pattern | Easy | 1294 | hash-tablestring |
| 295 | Find Median from Data Stream | Hard | 1973 | two-pointersdesignsorting+2 |
| 297 | Serialize and Deserialize Binary Tree | Hard | 1884 | stringtreedepth-first-search+3 |
| 300 | Longest Increasing Subsequence | Medium | 1666 | arraybinary-searchdynamic-programming |
| 303 | Range Sum Query - Immutable | Easy | 1185 | arraydesignprefix-sum |
| 304 | Range Sum Query 2D - Immutable | Medium | 1408 | arraydesignmatrix+1 |
| 305 | Number of Islands II | Hard | 1885 | arrayhash-tableunion-find+1 |
| 307 | Range Sum Query - Mutable | Medium | — | arraydivide-and-conquerdesign+2 |
| 309 | Best Time to Buy and Sell Stock with Cooldown | Medium | 1708 | arraydynamic-programming |
| 310 | Minimum Height Trees | Medium | 1657 | treedepth-first-searchbreadth-first-search+2 |
| 312 | Burst Balloons | Hard | 2056 | arraydynamic-programming |
| 314 | Binary Tree Vertical Order Traversal | Medium | — | treebreadth-first-searchhash-table |
| 315 | Count of Smaller Numbers After Self | Hard | 2215 | arraybinary-searchdivide-and-conquer+4 |
| 316 | Remove Duplicate Letters | Medium | 1568 | stringgreedystack+1 |
| 322 | Coin Change | Medium | 1684 | arraydynamic-programmingbreadth-first-search |
| 323 | Number of Connected Components in an Undirected Graph | Medium | 1558 | depth-first-searchbreadth-first-searchunion-find+1 |
| 326 | Power of Three | Easy | 1250 | mathrecursion |
| 327 | Count of Range Sum | Hard | — | arraybinary-searchdivide-and-conquer+4 |
| 328 | Odd Even Linked List | Medium | 1360 | linked-listtwo-pointers |
| 329 | Longest Increasing Path in a Matrix | Hard | 1965 | arraydynamic-programmingdepth-first-search+5 |
| 330 | Patching Array | Hard | 2073 | arraygreedy |
| 332 | Reconstruct Itinerary | Hard | 1858 | depth-first-searchgrapheulerian-circuit |
| 334 | Increasing Triplet Subsequence | Medium | — | arraygreedy |
| 336 | Palindrome Pairs | Hard | 2311 | arrayhash-tablestring+1 |
| 337 | House Robber III | Medium | — | dynamic-programmingtreedepth-first-search+1 |
| 338 | Counting Bits | Easy | 1203 | dynamic-programmingbit-manipulation |
| 340 | Longest Substring with At Most K Distinct Characters | Medium | 1679 | hash-tablestringsliding-window |
| 341 | Flatten Nested List Iterator | Medium | — | stacktreedepth-first-search+3 |
| 342 | Power of Four | Easy | 1286 | mathbit-manipulationrecursion |
| 343 | Integer Break | Medium | — | mathdynamic-programming |