| Nested List Weight Sum II | Medium | 66.7% | 100.0% | |
| All O`one Data Structure | Hard | 44.1% | 100.0% | Hash TableLinked ListDesign+1 |
| Max Stack | Hard | 45.9% | 100.0% | |
| Max Consecutive Ones III | Medium | 67.3% | 87.5% | ArrayBinary SearchSliding Window+1 |
| Letter Combinations of a Phone Number | Medium | 65.5% | 75.0% | Hash TableStringBacktracking |
| Valid Parentheses | Easy | 43.7% | 75.0% | StringStack |
| Find First and Last Position of Element in Sorted Array | Medium | 48.3% | 75.0% | ArrayBinary Search |
| Pow(x, n) | Medium | 38.2% | 75.0% | MathRecursion |
| Maximum Subarray | Medium | 53.0% | 75.0% | ArrayDivide and ConquerDynamic Programming |
| Word Ladder | Hard | 44.9% | 75.0% | Hash TableStringBreadth-First Search |
| Maximum Product Subarray | Medium | 36.0% | 75.0% | ArrayDynamic Programming |
| Binary Tree Upside Down | Medium | 65.3% | 75.0% | |
| Number of Islands | Medium | 63.8% | 75.0% | ArrayDepth-First SearchBreadth-First Search+2 |
| Shortest Word Distance II | Medium | 62.7% | 75.0% | |
| Find the Celebrity | Medium | 48.9% | 75.0% | |
| Nested List Weight Sum | Medium | 85.9% | 75.0% | |
| Find Leaves of Binary Tree | Medium | 81.3% | 75.0% | |
| Insert Delete GetRandom O(1) | Medium | 55.3% | 75.0% | ArrayHash TableMath+2 |
| Can Place Flowers | Easy | 29.0% | 75.0% | ArrayGreedy |
| Partition to K Equal Sum Subsets | Medium | 38.4% | 75.0% | ArrayDynamic ProgrammingBacktracking+3 |
| Search in Rotated Sorted Array | Medium | 44.1% | 62.5% | ArrayBinary Search |
| Permutations | Medium | 81.6% | 62.5% | ArrayBacktracking |
| Merge Intervals | Medium | 51.1% | 62.5% | ArraySorting |
| Minimum Window Substring | Hard | 46.9% | 62.5% | Hash TableStringSliding Window |
| Symmetric Tree | Easy | 60.7% | 62.5% | TreeDepth-First SearchBreadth-First Search+1 |
| Maximum Depth of Binary Tree | Easy | 77.9% | 62.5% | TreeDepth-First SearchBreadth-First Search+1 |
| Kth Smallest Product of Two Sorted Arrays | Hard | 48.9% | 62.5% | ArrayBinary Search |
| LRU Cache | Medium | 46.8% | 62.5% | Hash TableLinked ListDesign+1 |
| Repeated DNA Sequences | Medium | 52.9% | 62.5% | Hash TableStringBit Manipulation+3 |
| Isomorphic Strings | Easy | 48.0% | 62.5% | Hash TableString |
| Kth Largest Element in an Array | Medium | 68.8% | 62.5% | ArrayDivide and ConquerSorting+2 |
| Lowest Common Ancestor of a Binary Search Tree | Medium | 70.0% | 62.5% | TreeDepth-First SearchBinary Search Tree+1 |
| Lowest Common Ancestor of a Binary Tree | Medium | 68.7% | 62.5% | TreeDepth-First SearchBinary Tree |
| Shortest Word Distance | Easy | 66.2% | 62.5% | |
| Factor Combinations | Medium | 50.5% | 62.5% | |
| Paint House | Medium | 64.3% | 62.5% | |
| Closest Binary Search Tree Value II | Hard | 61.1% | 62.5% | |
| Serialize and Deserialize Binary Tree | Hard | 60.3% | 62.5% | StringTreeDepth-First Search+3 |
| Count Integers in Intervals | Hard | 35.6% | 62.5% | DesignSegment TreeOrdered Set |
| Sort Transformed Array | Medium | 57.8% | 62.5% | |
| Insert Delete GetRandom O(1) - Duplicates allowed | Hard | 36.4% | 62.5% | ArrayHash TableMath+2 |
| Exclusive Time of Functions | Medium | 66.1% | 62.5% | ArrayStack |
| Second Minimum Node In a Binary Tree | Easy | 45.9% | 62.5% | TreeDepth-First SearchBinary Tree |
| Find Smallest Letter Greater Than Target | Easy | 58.9% | 62.5% | ArrayBinary Search |
| Random Pick with Weight | Medium | 48.9% | 62.5% | ArrayMathBinary Search+2 |
| Design Bounded Blocking Queue | Medium | 73.6% | 62.5% | |
| Lowest Common Ancestor of a Binary Tree III | Medium | 82.9% | 62.5% | |
| Bulb Switcher | Medium | 55.5% | 62.5% | MathBrainteaser |
| Two Sum | Easy | 57.1% | 50.0% | ArrayHash Table |
| Merge Two Sorted Lists | Easy | 67.9% | 50.0% | Linked ListRecursion |
| Merge k Sorted Lists | Hard | 58.8% | 50.0% | Linked ListDivide and ConquerHeap (Priority Queue)+1 |
| Permutations II | Medium | 62.9% | 50.0% | ArrayBacktrackingSorting |
| Insert Interval | Medium | 44.7% | 50.0% | Array |
| Valid Number | Hard | 22.6% | 50.0% | String |
| Rotate List | Medium | 41.2% | 50.0% | Linked ListTwo Pointers |
| Text Justification | Hard | 50.4% | 50.0% | ArrayStringSimulation |
| Edit Distance | Medium | 60.1% | 50.0% | StringDynamic Programming |
| Binary Tree Zigzag Level Order Traversal | Medium | 63.1% | 50.0% | TreeBreadth-First SearchBinary Tree |
| Binary Tree Level Order Traversal | Medium | 72.2% | 50.0% | TreeBreadth-First SearchBinary Tree |
| Max Points on a Line | Hard | 30.2% | 50.0% | ArrayHash TableMath+1 |
| Evaluate Reverse Polish Notation | Medium | 57.0% | 50.0% | ArrayMathStack |
| Two Sum III - Data structure design | Easy | 39.1% | 50.0% | |
| Binary Search Tree Iterator | Medium | 76.1% | 50.0% | StackTreeDesign+3 |
| House Robber | Medium | 52.9% | 50.0% | ArrayDynamic Programming |
| Product of Array Except Self | Medium | 68.6% | 50.0% | ArrayPrefix Sum |
| Shortest Word Distance III | Medium | 59.4% | 50.0% | |
| Create Binary Tree From Descriptions | Medium | 81.7% | 50.0% | ArrayHash TableTree+1 |
| Graph Valid Tree | Medium | 49.8% | 50.0% | |
| Sparse Matrix Multiplication | Medium | 69.2% | 50.0% | |
| Flatten Nested List Iterator | Medium | 65.6% | 50.0% | StackTreeDepth-First Search+3 |
| Valid Perfect Square | Easy | 44.7% | 50.0% | MathBinary Search |
| Find K Pairs with Smallest Sums | Medium | 41.5% | 50.0% | ArrayHeap (Priority Queue) |
| Minimum Deletions to Make Array Divisible | Hard | 59.7% | 50.0% | ArrayMathSorting+2 |
| Can I Win | Medium | 31.0% | 50.0% | MathDynamic ProgrammingBit Manipulation+3 |
| Maximum Number of Non-overlapping Palindrome Substrings | Hard | 43.3% | 50.0% | Two PointersStringDynamic Programming+1 |
| Find Largest Value in Each Tree Row | Medium | 66.3% | 50.0% | TreeDepth-First SearchBreadth-First Search+1 |
| Longest Palindromic Subsequence | Medium | 65.1% | 50.0% | StringDynamic Programming |
| Maximize Total Tastiness of Purchased Fruits | Medium | 64.5% | 50.0% | |
| Time to Cross a Bridge | Hard | 44.3% | 50.0% | ArrayHeap (Priority Queue)Simulation |
| Sum of Square Numbers | Medium | 36.7% | 50.0% | MathTwo PointersBinary Search |
| Palindromic Substrings | Medium | 72.5% | 50.0% | Two PointersStringDynamic Programming |
| Count Different Palindromic Subsequences | Hard | 47.5% | 50.0% | StringDynamic Programming |
| Validate Stack Sequences | Medium | 70.2% | 50.0% | ArrayStackSimulation |
| Building H2O | Medium | 58.3% | 50.0% | Concurrency |
| New Users Daily Count | Medium | 44.9% | 50.0% | |
| User Purchase Platform | Hard | 46.2% | 50.0% | |
| Article Views I | Easy | 76.7% | 50.0% | Database |
| Article Views II | Medium | 47.3% | 50.0% | |
| Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold | Medium | 72.1% | 50.0% | ArraySliding Window |
| Sum of All Odd Length Subarrays | Easy | 83.9% | 50.0% | ArrayMathPrefix Sum |
| Lowest Common Ancestor of a Binary Tree II | Medium | 69.5% | 50.0% | |
| Possible Bipartition | Medium | 52.3% | 50.0% | Depth-First SearchBreadth-First SearchUnion-Find+1 |
| Robot Room Cleaner | Hard | 77.9% | 50.0% | |
| Accounts Merge | Medium | 60.9% | 50.0% | ArrayHash TableString+4 |
| Intersection of Two Linked Lists | Easy | 63.2% | 50.0% | Hash TableLinked ListTwo Pointers |
| Maximize Subarrays After Removing One Conflicting Pair | Hard | 64.7% | 50.0% | ArraySegment TreeEnumeration+1 |
| Integer to Roman | Medium | 70.4% | 37.5% | Hash TableMathString |
| Word Ladder II | Hard | 27.5% | 37.5% | Hash TableStringBacktracking+1 |
| Min Stack | Medium | 57.7% | 37.5% | StackDesign |
| Number of Connected Components in an Undirected Graph | Medium | 64.8% | 37.5% | |
| Shuffle an Array | Medium | 59.5% | 37.5% | ArrayMathDesign+1 |
| Valid Triangle Number | Medium | 56.7% | 37.5% | ArrayTwo PointersBinary Search+2 |
| Find K Closest Elements | Medium | 49.4% | 37.5% | ArrayTwo PointersBinary Search+3 |
| Max Area of Island | Medium | 73.8% | 37.5% | ArrayDepth-First SearchBreadth-First Search+2 |
| Design HashMap | Easy | 66.4% | 37.5% | ArrayHash TableLinked List+2 |
| Minimum Knight Moves | Medium | 41.7% | 37.5% | |
| Combination Sum II | Medium | 59.0% | 37.5% | ArrayBacktracking |
| Course Schedule II | Medium | 55.0% | 37.5% | Depth-First SearchBreadth-First SearchGraph Theory+1 |
| Implement Rand10() Using Rand7() | Medium | 46.2% | 37.5% | MathRejection SamplingRandomized+1 |
| Sqrt(x) | Easy | 41.4% | 37.5% | MathBinary Search |
| Paint House II | Hard | 56.9% | 37.5% | |
| Longest Valid Parentheses | Hard | 38.0% | 37.5% | StringDynamic ProgrammingStack |
| Smallest Range Covering Elements from K Lists | Hard | 70.0% | 37.5% | ArrayHash TableGreedy+3 |
| Merge Two Binary Trees | Easy | 79.0% | 37.5% | TreeDepth-First SearchBreadth-First Search+1 |
| Reverse Words in a String | Medium | 55.5% | 37.5% | Two PointersString |
| LFU Cache | Hard | 48.6% | 37.5% | Hash TableLinked ListDesign+1 |
| Longest Substring Without Repeating Characters | Medium | 38.5% | 25.0% | Hash TableStringSliding Window |
| Median of Two Sorted Arrays | Hard | 45.9% | 25.0% | ArrayBinary SearchDivide and Conquer |
| Longest Palindromic Substring | Medium | 37.3% | 25.0% | Two PointersStringDynamic Programming |
| Combination Sum | Medium | 76.1% | 25.0% | ArrayBacktracking |
| Merge Sorted Array | Easy | 54.4% | 25.0% | ArrayTwo PointersSorting |
| Same Tree | Easy | 66.6% | 25.0% | TreeDepth-First SearchBreadth-First Search+1 |
| Best Time to Buy and Sell Stock | Easy | 56.4% | 25.0% | ArrayDynamic Programming |
| Reorder List | Medium | 64.6% | 25.0% | Linked ListTwo PointersStack+1 |
| Design Add and Search Words Data Structure | Medium | 48.1% | 25.0% | StringDepth-First SearchDesign+1 |
| House Robber II | Medium | 44.6% | 25.0% | ArrayDynamic Programming |
| Diameter of Binary Tree | Easy | 65.0% | 25.0% | TreeDepth-First SearchBinary Tree |
| House Robber IV | Medium | 64.8% | 25.0% | ArrayBinary SearchDynamic Programming+1 |
| Partition Labels | Medium | 81.8% | 25.0% | Hash TableTwo PointersString+1 |
| K Closest Points to Origin | Medium | 68.7% | 25.0% | ArrayMathDivide and Conquer+4 |
| Design Authentication Manager | Medium | 58.4% | 25.0% | Hash TableLinked ListDesign+1 |
| Find the Index of the First Occurrence in a String | Easy | 46.2% | 25.0% | Two PointersStringString Matching |
| Valid Sudoku | Medium | 64.1% | 25.0% | ArrayHash TableMatrix |
| Word Break | Medium | 49.1% | 25.0% | ArrayHash TableString+3 |
| Roman to Integer | Easy | 66.2% | 25.0% | Hash TableMathString |
| Unique Paths | Medium | 66.5% | 25.0% | MathDynamic ProgrammingCombinatorics |
| Invert Binary Tree | Easy | 79.8% | 25.0% | TreeDepth-First SearchBreadth-First Search+1 |
| Minimum Add to Make Parentheses Valid | Medium | 74.4% | 25.0% | StringStackGreedy |
| Closest Leaf in a Binary Tree | Medium | 47.4% | 25.0% | |
| Dot Product of Two Sparse Vectors | Medium | 89.9% | 25.0% | |
| H-Index | Medium | 41.1% | 25.0% | ArraySortingCounting Sort |
| Long Pressed Name | Easy | 32.8% | 25.0% | Two PointersString |
| 01 Matrix | Medium | 53.3% | 25.0% | ArrayDynamic ProgrammingBreadth-First Search+1 |
| Koko Eating Bananas | Medium | 49.7% | 25.0% | ArrayBinary Search |
| Number of Divisible Triplet Sums | Medium | 67.6% | 25.0% | |
| Expression Add Operators | Hard | 42.8% | 25.0% | MathStringBacktracking |
| Valid Parenthesis String | Medium | 39.8% | 25.0% | StringDynamic ProgrammingStack+1 |
| Is Graph Bipartite? | Medium | 58.9% | 25.0% | Depth-First SearchBreadth-First SearchUnion-Find+1 |
| Serialize and Deserialize N-ary Tree | Hard | 68.6% | 25.0% | |
| Kth Smallest Element in a BST | Medium | 76.5% | 25.0% | TreeDepth-First SearchBinary Search Tree+1 |
| Delete Node in a BST | Medium | 54.2% | 25.0% | TreeBinary Search TreeBinary Tree |
| Number of Visible People in a Queue | Hard | 72.3% | 25.0% | ArrayStackMonotonic Stack |
| Flatten a Multilevel Doubly Linked List | Medium | 62.5% | 25.0% | Linked ListDepth-First SearchDoubly-Linked List |
| Largest Color Value in a Directed Graph | Hard | 57.4% | 25.0% | Hash TableStringDynamic Programming+4 |
| House Robber III | Medium | 55.6% | 25.0% | Dynamic ProgrammingTreeDepth-First Search+1 |
| Cinema Seat Allocation | Medium | 43.6% | 25.0% | ArrayHash TableGreedy+1 |
| Integer to English Words | Hard | 34.8% | 25.0% | MathStringRecursion |
| Task Scheduler | Medium | 62.6% | 25.0% | ArrayHash TableGreedy+3 |
| Find Minimum in Rotated Sorted Array | Medium | 53.8% | 25.0% | ArrayBinary Search |
| Reverse Integer | Medium | 31.5% | 25.0% | Math |
| Stock Price Fluctuation | Medium | 48.9% | 25.0% | Hash TableDesignHeap (Priority Queue)+2 |
| Evaluate Division | Medium | 64.0% | 25.0% | ArrayStringDepth-First Search+4 |
| Process Tasks Using Servers | Medium | 41.9% | 25.0% | ArrayHeap (Priority Queue) |
| Minimum Window Subsequence | Hard | 43.8% | 25.0% | |
| Word Search | Medium | 46.8% | 25.0% | ArrayStringBacktracking+2 |
| Paint House III | Hard | 61.2% | 25.0% | ArrayDynamic Programming |
| Partition Equal Subset Sum | Medium | 49.2% | 25.0% | ArrayDynamic Programming |
| Longest String Chain | Medium | 62.8% | 25.0% | ArrayHash TableTwo Pointers+3 |
| Find the Number of Subarrays Where Boundary Elements Are Maximum | Hard | 32.8% | 25.0% | ArrayBinary SearchStack+1 |
| Subarray Sum Equals K | Medium | 46.8% | 25.0% | ArrayHash TablePrefix Sum |
| 4Sum | Medium | 40.0% | 25.0% | ArrayTwo PointersSorting |
| Making A Large Island | Hard | 56.3% | 25.0% | ArrayDepth-First SearchBreadth-First Search+2 |
| Robot Bounded In Circle | Medium | 56.4% | 25.0% | MathStringSimulation |
| Course Schedule | Medium | 50.8% | 25.0% | Depth-First SearchBreadth-First SearchGraph Theory+1 |
| Longest Consecutive Sequence | Medium | 47.0% | 25.0% | ArrayHash TableUnion-Find |
| Best Meeting Point | Hard | 61.4% | 25.0% | |
| Validate Binary Search Tree | Medium | 35.3% | 25.0% | TreeDepth-First SearchBinary Search Tree+1 |
| The Maze | Medium | 60.3% | 25.0% | |
| Largest Rectangle in Histogram | Hard | 49.3% | 25.0% | ArrayStackMonotonic Stack |
| Open the Lock | Medium | 61.1% | 25.0% | ArrayHash TableString+1 |