| 377 | Combination Sum IV | Medium | 1609 | arraydynamic-programming |
| 378 | Kth Smallest Element in a Sorted Matrix | Medium | 1457 | arraybinary-searchsorting+2 |
| 380 | Insert Delete GetRandom O(1) | Medium | 1571 | arrayhash-tablemath+2 |
| 384 | Shuffle an Array | Medium | — | arraymathdesign+1 |
| 386 | Lexicographical Numbers | Medium | 1433 | depth-first-searchtrie |
| 394 | Decode String | Medium | 1540 | stackstringrecursion |
| 399 | Evaluate Division | Medium | 1747 | arraystringdepth-first-search+4 |
| 400 | Nth Digit | Medium | 1648 | mathbinary-search |
| 402 | Remove K Digits | Medium | 1792 | stringgreedystack+1 |
| 406 | Queue Reconstruction by Height | Medium | 1506 | arraygreedysorting |
| 416 | Partition Equal Subset Sum | Medium | 1624 | arraydynamic-programming |
| 417 | Pacific Atlantic Water Flow | Medium | 1707 | arraydepth-first-searchbreadth-first-search+1 |
| 421 | Maximum XOR of Two Numbers in an Array | Medium | 1712 | arrayhash-tablebit-manipulation+1 |
| 424 | Longest Repeating Character Replacement | Medium | 1680 | hash-tablestringsliding-window |
| 427 | Construct Quad Tree | Medium | 1464 | arraydivide-and-conquertree+1 |
| 433 | Minimum Genetic Mutation | Medium | 1671 | hash-tablestringbreadth-first-search |
| 435 | Non-overlapping Intervals | Medium | 1567 | arraydynamic-programminggreedy+1 |
| 436 | Find Right Interval | Medium | 1416 | arraybinary-searchsorting |
| 437 | Path Sum III | Medium | — | treedepth-first-searchbinary-tree |
| 438 | Find All Anagrams in a String | Medium | 1483 | hash-tablestringsliding-window |
| 443 | String Compression | Medium | 1449 | stringtwo-pointers |
| 445 | Add Two Numbers II | Medium | — | linked-listmathstack |
| 449 | Serialize and Deserialize BST | Medium | — | stringtreedepth-first-search+4 |
| 450 | Delete Node in a BST | Medium | 1590 | treebinary-search-treebinary-tree |
| 452 | Minimum Number of Arrows to Burst Balloons | Medium | 1703 | arraygreedysorting |
| 456 | 132 Pattern | Medium | 1804 | arraybinary-searchstack+2 |
| 473 | Matchsticks to Square | Medium | — | arraydynamic-programmingbacktracking+2 |
| 474 | Ones and Zeroes | Medium | — | arraystringdynamic-programming |
| 477 | Total Hamming Distance | Medium | 1489 | arraymathbit-manipulation |
| 478 | Generate Random Point in a Circle | Medium | — | mathgeometryrejection-sampling+1 |
| 486 | Predict the Winner | Medium | — | arraymathdynamic-programming+2 |
| 494 | Target Sum | Medium | 1679 | arraydynamic-programmingbacktracking |
| 497 | Random Point in Non-overlapping Rectangles | Medium | — | arraymathbinary-search+4 |
| 503 | Next Greater Element II | Medium | 1513 | arraystackmonotonic-stack |
| 513 | Find Bottom Left Tree Value | Medium | — | treedepth-first-searchbreadth-first-search+1 |
| 516 | Longest Palindromic Subsequence | Medium | — | stringdynamic-programming |
| 518 | Coin Change II | Medium | 1697 | arraydynamic-programming |
| 523 | Continuous Subarray Sum | Medium | 1748 | arrayhash-tablemath+1 |
| 525 | Contiguous Array | Medium | 1708 | arrayhash-tableprefix-sum |
| 526 | Beautiful Arrangement | Medium | 1591 | backtrackingbit-manipulation |
| 528 | Random Pick with Weight | Medium | 1416 | arraymathbinary-search+2 |
| 535 | Encode and Decode TinyURL | Medium | — | hash-tablestringdesign+1 |
| 538 | Convert BST to Greater Tree | Medium | — | treedepth-first-searchbinary-search-tree+1 |
| 540 | Single Element in a Sorted Array | Medium | — | arraybinary-search |
| 542 | 01 Matrix | Medium | 1538 | arraydynamic-programmingbreadth-first-search+1 |
| 547 | Number of Provinces | Medium | 1400 | graphdfsunion-find |
| 554 | Brick Wall | Medium | 1483 | arrayhash-table |
| 560 | Subarray Sum Equals K | Medium | 1621 | arrayhash-tableprefix-sum |
| 567 | Permutation in String | Medium | 1584 | hash-tabletwo-pointersstring+1 |
| 606 | Construct String from Binary Tree | Medium | — | stringtreedepth-first-search+1 |