171 problems
| Problem | Difficulty | Frequency ↓ | Topics |
|---|---|---|---|
| Max Stack | Hard | 100% | TopicsLinked ListStackDesignDoubly-Linked ListOrdered Set |
| Nested List Weight Sum II | Medium | 96.1% | TopicsStackDepth-First SearchBreadth-First Search |
| All O`one Data Structure | Hard | 93.2% | TopicsHash TableLinked ListDesignDoubly-Linked List |
| 1004. Max Consecutive Ones III | Medium | 83.2% | TopicsArrayBinary SearchSliding WindowPrefix Sum |
| Shortest Word Distance II | Medium | 82.6% | TopicsArrayHash TableTwo PointersStringDesign |
| 53. Maximum Subarray | Medium | 80.6% | TopicsArrayDivide and ConquerDynamic Programming |
| Nested List Weight Sum | Medium | 80.3% | TopicsDepth-First SearchBreadth-First Search |
| Find the Celebrity | Medium | 79.9% | TopicsTwo PointersGraph TheoryInteractive |
| 20. Valid Parentheses | Easy | 78.8% | TopicsStringStackBracket Sequences |
| 127. Word Ladder | Hard | 77.6% | TopicsHash TableStringBreadth-First SearchBidirectional Search |
| 605. Can Place Flowers | Easy | 77.6% | TopicsArrayGreedy |
| Find Leaves of Binary Tree | Medium | 76.4% | TopicsTreeDepth-First SearchBinary TreeDP on Trees |
| Insert Delete GetRandom O(1) | Medium | 75.9% | TopicsArrayHash TableMathDesignRandomized |
| 17. Letter Combinations of a Phone Number | Medium | 75% | TopicsHash TableStringBacktracking |
| 200. Number of Islands | Medium | 74.5% | TopicsArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix |
| 152. Maximum Product Subarray | Medium | 72% | TopicsArrayDynamic Programming |
| 34. Find First and Last Position of Element in Sorted Array | Medium | 70.9% | TopicsArrayBinary Search |
| Binary Tree Upside Down | Medium | 70.3% | TopicsTreeDepth-First SearchBinary Tree |
| Pow(x, n) | Medium | 69.7% | TopicsMathRecursion |
| Bulb Switcher | Medium | 68.4% | TopicsMathBrainteaser |
| 33. Search in Rotated Sorted Array | Medium | 67% | TopicsArrayBinary Search |
| 76. Minimum Window Substring | Hard | 67% | TopicsHash TableStringSliding Window |
| Sort Transformed Array | Medium | 67% | TopicsArrayMathTwo PointersSorting |
| 698. Partition to K Equal Sum Subsets | Medium | 67% | TopicsArrayDynamic ProgrammingBacktrackingBit ManipulationMemoizationBitmask |
| 104. Maximum Depth of Binary Tree | Easy | 66.3% | TopicsTreeDepth-First SearchBreadth-First SearchBinary Tree |
