| 1. Two SumOpen source | Easy | ArrayHash Table |
| 15. 3SumOpen source | Medium | ArrayTwo PointersSorting |
| 31. Next PermutationOpen source | Medium | ArrayTwo Pointers |
| 33. Search in Rotated Sorted ArrayOpen source | Medium | ArrayBinary Search |
| 42. Trapping Rain WaterOpen source | Hard | ArrayTwo PointersDynamic Programming+2 more |
| 48. Rotate ImageOpen source | Medium | ArrayMathMatrix |
| 53. Maximum SubarrayOpen source | Medium | ArrayDivide and ConquerDynamic Programming |
| 54. Spiral MatrixOpen source | Medium | ArrayMatrixSimulation |
| 56. Merge IntervalsOpen source | Medium | ArraySortingQuicksort |
| 57. Insert IntervalOpen source | Medium | Array |
| 73. Set Matrix ZeroesOpen source | Medium | ArrayHash TableMatrix |
| 74. Search a 2D MatrixOpen source | Medium | ArrayBinary SearchMatrix |
| 79. Word SearchOpen source | Medium | ArrayStringBacktracking+2 more |
| 118. Pascal's TriangleOpen source | Easy | ArrayDynamic Programming |
| 121. Best Time to Buy and Sell StockOpen source | Easy | ArrayDynamic Programming |
| 128. Longest Consecutive SequenceOpen source | Medium | ArrayHash TableUnion-Find |
| 139. Word BreakOpen source | Medium | ArrayHash TableString+4 more |
| 152. Maximum Product SubarrayOpen source | Medium | ArrayDynamic Programming |
| 153. Find Minimum in Rotated Sorted ArrayOpen source | Medium | ArrayBinary Search |
| 169. Majority ElementOpen source | Easy | ArrayHash TableDivide and Conquer+3 more |
| 198. House RobberOpen source | Medium | ArrayDynamic Programming |
| 200. Number of IslandsOpen source | Medium | ArrayDepth-First SearchBreadth-First Search+2 more |
| 215. Kth Largest Element in an ArrayOpen source | Medium | ArrayDivide and ConquerSorting+2 more |
| 217. Contains DuplicateOpen source | Easy | ArrayHash TableSorting |
| 238. Product of Array Except SelfOpen source | Medium | ArrayPrefix Sum |