| 15 | 3Sum | — | Medium | ArrayTwo PointersSorting | 37% | |
| 16 | 3Sum Closest | — | Medium | ArrayTwo PointersSorting | 47% | |
| 18 | 4Sum | — | Medium | ArrayTwo PointersSorting | 38% | |
| 47 | Permutations II | — | Medium | ArrayBacktrackingSorting | 61% | |
| 49 | Group Anagrams | — | Medium | ArrayHash TableString | 71% | |
| 56 | Merge Intervals | — | Medium | ArraySorting | 49% | |
| 75 | Sort Colors | — | Medium | ArrayTwo PointersSorting | 67% | |
| 88 | Merge Sorted Array | — | Easy | ArrayTwo PointersSorting | 53% | |
| 147 | Insertion Sort List | — | Medium | Linked ListSorting | 56% | |
| 148 | Sort List | — | Medium | Linked ListTwo PointersDivide and Conquer | 61% | |
| 164 | Maximum Gap | — | Medium | ArraySortingBucket Sort | 49% | |
| 169 | Majority Element | — | Easy | ArrayHash TableDivide and Conquer | 66% | |
| 179 | Largest Number | — | Medium | ArrayStringGreedy | 41% | |
| 215 | Kth Largest Element in an Array | — | Medium | ArrayDivide and ConquerSorting | 68% | |
| 217 | Contains Duplicate | — | Easy | ArrayHash TableSorting | 63% | |
| 220 | Contains Duplicate IIIread | — | Hard | ArraySliding WindowSorting | 24% | |
| 229 | Majority Element II | — | Medium | ArrayHash TableSorting | 54% | |
| 242 | Valid Anagram | — | Easy | Hash TableStringSorting | 66% | |
| 252 | Meeting Rooms | — | Easy | ArraySorting | 59% | |
| 253 | Meeting Rooms II | — | Medium | ArrayTwo PointersGreedy | 52% | |
| 268 | Missing Number | — | Easy | ArrayHash TableMath | 70% | |
| 274 | H-Index | — | Medium | ArraySortingCounting Sort | 40% | |
| 295 | Find Median from Data Streamread | — | Hard | Two PointersDesignSorting | 53% | |
| 324 | Wiggle Sort IIread | — | Medium | ArrayDivide and ConquerGreedy | 36% | |
| 347 | Top K Frequent Elementsread | — | Medium | ArrayHash TableDivide and Conquer | 64% | |
| 349 | Intersection of Two Arrays | — | Easy | ArrayHash TableTwo Pointers | 76% | |
| 350 | Intersection of Two Arrays II | — | Easy | ArrayHash TableTwo Pointers | 59% | |
| 354 | Russian Doll Envelopes | — | Hard | ArrayBinary SearchDynamic Programming | 37% | |
| 368 | Largest Divisible Subset | — | Medium | ArrayMathDynamic Programming | 49% | |
| 378 | Kth Smallest Element in a Sorted Matrix | — | Medium | ArrayBinary SearchSorting | 63% | |
| 389 | Find the Difference | — | Easy | Hash TableStringBit Manipulation | 60% | |
| 406 | Queue Reconstruction by Height | — | Medium | ArrayBinary Indexed TreeSegment Tree | 74% | |
| 414 | Third Maximum Number | — | Easy | ArraySorting | 37% | |
| 435 | Non-overlapping Intervals | — | Medium | ArrayDynamic ProgrammingGreedy | 55% | |
| 436 | Find Right Interval | — | Medium | ArrayBinary SearchSorting | 54% | |
| 451 | Sort Characters By Frequency | — | Medium | Hash TableStringSorting | 74% | |
| 452 | Minimum Number of Arrows to Burst Balloons | — | Medium | ArrayGreedySorting | 60% | |
| 455 | Assign Cookiesread | — | Easy | ArrayTwo PointersGreedy | 54% | |
| 462 | Minimum Moves to Equal Array Elements II | — | Medium | ArrayMathSorting | 61% | |
| 475 | Heaters | — | Medium | ArrayTwo PointersBinary Search | 40% | |
| 502 | IPOread | — | Hard | ArrayGreedySorting | 53% | |
| 506 | Relative Ranksread | — | Easy | ArraySortingHeap (Priority Queue) | 73% | |
| 522 | Longest Uncommon Subsequence II | — | Medium | ArrayHash TableTwo Pointers | 43% | |
| 524 | Longest Word in Dictionary through Deleting | — | Medium | ArrayTwo PointersString | 52% | |
| 532 | K-diff Pairs in an Array | — | Medium | ArrayHash TableTwo Pointers | 45% | |
| 539 | Minimum Time Differenceread | — | Medium | ArrayMathString | 62% | |
| 561 | Array Partition | — | Easy | ArrayGreedySorting | 80% | |
| 581 | Shortest Unsorted Continuous Subarray | — | Medium | ArrayTwo PointersStack | 37% | |
| 594 | Longest Harmonious Subsequence | — | Easy | ArrayHash TableSliding Window | 57% | |
| 611 | Valid Triangle Number | — | Medium | ArrayTwo PointersBinary Search | 52% | |