| Minimum Remove to Make Valid Parentheses | Medium | 71.3% | 100.0% | StringStack |
| Valid Word Abbreviation | Easy | 37.0% | 95.4% | Two PointersString |
| Binary Tree Vertical Order Traversal | Medium | 57.8% | 93.4% | Hash TableTreeDepth-First Search+3 |
| Valid Palindrome II | Easy | 44.0% | 92.7% | Two PointersStringGreedy |
| Lowest Common Ancestor of a Binary Tree III | Medium | 82.9% | 89.6% | Hash TableTwo PointersTree+1 |
| Merge Sorted Array | Easy | 54.4% | 88.1% | ArrayTwo PointersSorting |
| Kth Largest Element in an Array | Medium | 68.8% | 86.9% | ArrayDivide and ConquerSorting+2 |
| Pow(x, n) | Medium | 38.3% | 86.9% | MathRecursion |
| Binary Tree Right Side View | Medium | 69.5% | 86.0% | TreeDepth-First SearchBreadth-First Search+1 |
| Simplify Path | Medium | 50.0% | 85.9% | StringStack |
| Merge Intervals | Medium | 51.2% | 84.8% | ArraySorting |
| Basic Calculator II | Medium | 46.7% | 84.0% | MathStringStack |
| Two Sum | Easy | 57.1% | 83.8% | ArrayHash Table |
| Lowest Common Ancestor of a Binary Tree | Medium | 68.8% | 82.9% | TreeDepth-First SearchBinary Tree |
| Find Peak Element | Medium | 46.8% | 82.9% | ArrayBinary Search |
| Nested List Weight Sum | Medium | 85.9% | 81.7% | Depth-First SearchBreadth-First Search |
| Random Pick with Weight | Medium | 48.9% | 80.5% | ArrayMathBinary Search+2 |
| Sum Root to Leaf Numbers | Medium | 69.6% | 80.5% | TreeDepth-First SearchBinary Tree |
| Diameter of Binary Tree | Easy | 65.1% | 79.2% | TreeDepth-First SearchBinary Tree |
| Next Permutation | Medium | 44.8% | 78.3% | ArrayTwo Pointers |
| Top K Frequent Elements | Medium | 65.9% | 77.9% | ArrayHash TableDivide and Conquer+5 |
| Merge k Sorted Lists | Hard | 58.9% | 77.2% | Linked ListDivide and ConquerHeap (Priority Queue)+1 |
| 3Sum | Medium | 38.6% | 76.7% | ArrayTwo PointersSorting |
| Best Time to Buy and Sell Stock | Easy | 56.4% | 76.4% | ArrayDynamic Programming |
| Buildings With an Ocean View | Medium | 80.9% | 74.9% | ArrayStackMonotonic Stack |
| Custom Sort String | Medium | 72.3% | 73.2% | Hash TableStringSorting |
| Find First and Last Position of Element in Sorted Array | Medium | 48.4% | 72.1% | ArrayBinary Search |
| K Closest Points to Origin | Medium | 68.8% | 71.4% | ArrayMathDivide and Conquer+4 |
| Clone Graph | Medium | 64.7% | 71.4% | Hash TableDepth-First SearchBreadth-First Search+1 |
| Subarray Sum Equals K | Medium | 46.8% | 71.4% | ArrayHash TablePrefix Sum |
| Valid Parentheses | Easy | 43.7% | 71.1% | StringStack |
| Valid Number | Hard | 22.6% | 70.2% | String |
| Range Sum of BST | Easy | 87.6% | 69.5% | TreeDepth-First SearchBinary Search Tree+1 |
| Dot Product of Two Sparse Vectors | Medium | 89.9% | 69.5% | ArrayHash TableTwo Pointers+1 |
| Valid Palindrome | Easy | 52.8% | 69.5% | Two PointersString |
| Minimum Window Substring | Hard | 47.0% | 68.6% | Hash TableStringSliding Window |
| Shortest Path in Binary Matrix | Medium | 51.1% | 67.4% | ArrayBreadth-First SearchMatrix |
| Copy List with Random Pointer | Medium | 62.4% | 67.4% | Hash TableLinked List |
| Longest Common Prefix | Easy | 47.1% | 66.7% | StringTrie |
| Add Two Numbers | Medium | 48.0% | 65.1% | Linked ListMathRecursion |
| Sliding Window Median | Hard | 38.9% | 65.0% | ArrayHash TableSliding Window+1 |
| Making A Large Island | Hard | 56.3% | 65.0% | ArrayDepth-First SearchBreadth-First Search+2 |
| Subsets | Medium | 82.1% | 64.1% | ArrayBacktrackingBit Manipulation |
| Letter Combinations of a Phone Number | Medium | 65.5% | 64.1% | Hash TableStringBacktracking |
| Remove Nth Node From End of List | Medium | 51.0% | 63.6% | Linked ListTwo Pointers |
| Longest Substring Without Repeating Characters | Medium | 38.5% | 63.1% | Hash TableStringSliding Window |
| Accounts Merge | Medium | 60.9% | 62.4% | ArrayHash TableString+4 |
| LRU Cache | Medium | 46.8% | 62.4% | Hash TableLinked ListDesign+1 |
| Max Consecutive Ones III | Medium | 67.3% | 62.4% | ArrayBinary SearchSliding Window+1 |
| Trapping Rain Water | Hard | 66.8% | 60.6% | ArrayTwo PointersDynamic Programming+2 |
| String to Integer (atoi) | Medium | 20.6% | 59.7% | String |
| Kth Missing Positive Number | Easy | 63.2% | 59.4% | ArrayBinary Search |
| Squares of a Sorted Array | Easy | 73.6% | 59.4% | ArrayTwo PointersSorting |
| Longest Palindromic Substring | Medium | 37.4% | 59.0% | Two PointersStringDynamic Programming |
| Remove Duplicates from Sorted Array | Easy | 62.3% | 59.0% | ArrayTwo Pointers |
| Median of Two Sorted Arrays | Hard | 46.0% | 58.2% | ArrayBinary SearchDivide and Conquer |
| Palindrome Number | Easy | 60.3% | 57.0% | Math |
| Search in Rotated Sorted Array | Medium | 44.1% | 57.0% | ArrayBinary Search |
| Roman to Integer | Easy | 66.3% | 56.3% | Hash TableMathString |
| Diagonal Traverse | Medium | 67.0% | 56.0% | ArrayMatrixSimulation |
| Missing Ranges | Easy | 35.5% | 56.0% | Array |
| Moving Average from Data Stream | Easy | 80.2% | 56.0% | ArrayDesignQueue+1 |
| Exclusive Time of Functions | Medium | 66.1% | 56.0% | ArrayStack |
| Merge Two Sorted Lists | Easy | 68.0% | 53.9% | Linked ListRecursion |
| Group Anagrams | Medium | 72.2% | 53.6% | ArrayHash TableString+1 |
| Count and Say | Medium | 62.3% | 53.4% | String |
| Climbing Stairs | Easy | 53.9% | 52.8% | MathDynamic ProgrammingMemoization |
| Maximum Subarray | Medium | 53.0% | 52.1% | ArrayDivide and ConquerDynamic Programming |
| Add Strings | Easy | 52.1% | 51.9% | MathStringSimulation |
| Binary Search Tree Iterator | Medium | 76.2% | 51.9% | StackTreeDesign+3 |
| Minimum Add to Make Parentheses Valid | Medium | 74.4% | 51.9% | StringStackGreedy |
| Robot Room Cleaner | Hard | 77.9% | 51.9% | BacktrackingInteractive |
| Container With Most Water | Medium | 59.6% | 51.8% | ArrayTwo PointersGreedy |
| Sort Colors | Medium | 69.2% | 51.2% | ArrayTwo PointersSorting |
| Set Matrix Zeroes | Medium | 62.5% | 51.2% | ArrayHash TableMatrix |
| Add Binary | Easy | 57.7% | 50.8% | MathStringBit Manipulation+1 |
| Multiply Strings | Medium | 43.6% | 50.1% | MathStringSimulation |
| Reverse Integer | Medium | 31.5% | 49.4% | Math |
| Word Search | Medium | 46.9% | 48.3% | ArrayStringBacktracking+2 |
| Generate Parentheses | Medium | 78.3% | 47.5% | StringDynamic ProgrammingBacktracking |
| Plus One | Easy | 49.6% | 47.5% | ArrayMath |
| Rotate Image | Medium | 79.4% | 47.1% | ArrayMathMatrix |
| Remove Invalid Parentheses | Hard | 49.8% | 47.0% | StringBacktrackingBreadth-First Search |
| Palindromic Substrings | Medium | 72.6% | 47.0% | Two PointersStringDynamic Programming |
| Continuous Subarray Sum | Medium | 31.2% | 47.0% | ArrayHash TableMath+1 |
| Closest Binary Search Tree Value | Easy | 49.3% | 47.0% | Binary SearchTreeDepth-First Search+2 |
| Vertical Order Traversal of a Binary Tree | Hard | 53.3% | 47.0% | Hash TableTreeDepth-First Search+3 |
| Group Shifted Strings | Medium | 67.7% | 47.0% | ArrayHash TableString |
| Course Schedule | Medium | 50.8% | 47.0% | Depth-First SearchBreadth-First SearchGraph+1 |
| Insert into a Sorted Circular Linked List | Medium | 38.5% | 47.0% | Linked List |
| All Nodes Distance K in Binary Tree | Medium | 67.4% | 47.0% | Hash TableTreeDepth-First Search+2 |
| Convert Binary Search Tree to Sorted Doubly Linked List | Medium | 65.6% | 47.0% | Linked ListStackTree+4 |
| Spiral Matrix | Medium | 56.2% | 46.6% | ArrayMatrixSimulation |
| Regular Expression Matching | Hard | 30.5% | 46.2% | StringDynamic ProgrammingRecursion |
| Majority Element | Easy | 66.1% | 46.0% | ArrayHash TableDivide and Conquer+2 |
| Insert Interval | Medium | 44.8% | 45.3% | Array |
| Expression Add Operators | Hard | 42.8% | 45.2% | MathStringBacktracking |
| Find the Index of the First Occurrence in a String | Easy | 46.3% | 44.8% | Two PointersStringString Matching |
| Sqrt(x) | Easy | 41.4% | 44.3% | MathBinary Search |
| Search a 2D Matrix | Medium | 53.6% | 43.3% | ArrayBinary SearchMatrix |
| Binary Tree Zigzag Level Order Traversal | Medium | 63.2% | 43.3% | TreeBreadth-First SearchBinary Tree |
| Divide Two Integers | Medium | 19.4% | 43.3% | MathBit Manipulation |
| Number of Islands | Medium | 63.8% | 43.1% | ArrayDepth-First SearchBreadth-First Search+2 |
| Largest Rectangle in Histogram | Hard | 49.4% | 42.7% | ArrayStackMonotonic Stack |
| Binary Tree Level Order Traversal | Medium | 72.2% | 42.7% | TreeBreadth-First SearchBinary Tree |
| Unique Paths | Medium | 66.6% | 42.2% | MathDynamic ProgrammingCombinatorics |
| Remove Duplicates from Sorted Array II | Medium | 64.3% | 42.2% | ArrayTwo Pointers |
| Remove Element | Easy | 61.4% | 41.6% | ArrayTwo Pointers |
| Jump Game | Medium | 40.5% | 41.6% | ArrayDynamic ProgrammingGreedy |
| Text Justification | Hard | 50.5% | 41.0% | ArrayStringSimulation |
| Validate Binary Search Tree | Medium | 35.4% | 41.0% | TreeDepth-First SearchBinary Search Tree+1 |
| Product of Two Run-Length Encoded Arrays | Medium | 59.6% | 40.9% | ArrayTwo Pointers |
| Contains Duplicate II | Easy | 50.8% | 40.7% | ArrayHash TableSliding Window |
| Zero Array Transformation III | Medium | 54.9% | 40.7% | ArrayGreedySorting+2 |
| Swim in Rising Water | Hard | 67.6% | 40.7% | ArrayBinary SearchDepth-First Search+4 |
| Managers with at Least 5 Direct Reports | Medium | 48.9% | 40.7% | Database |
| Maximum Swap | Medium | 51.9% | 40.7% | MathGreedy |
| Cutting Ribbons | Medium | 53.0% | 40.7% | ArrayBinary Search |
| Word Break | Medium | 49.1% | 40.7% | ArrayHash TableString+3 |
| Binary Tree Maximum Path Sum | Hard | 42.0% | 40.7% | Dynamic ProgrammingTreeDepth-First Search+1 |
| Car Pooling | Medium | 56.2% | 40.7% | ArraySortingHeap (Priority Queue)+2 |
| Strobogrammatic Number | Easy | 47.5% | 40.7% | Hash TableTwo PointersString |
| Capacity To Ship Packages Within D Days | Medium | 73.5% | 40.7% | ArrayBinary Search |
| Word Ladder | Hard | 44.9% | 40.7% | Hash TableStringBreadth-First Search |
| Find Median from Data Stream | Hard | 54.2% | 40.7% | Two PointersDesignSorting+2 |
| Valid Palindrome III | Hard | 49.1% | 40.7% | StringDynamic Programming |
| Kth Smallest Element in a Sorted Matrix | Medium | 64.4% | 40.7% | ArrayBinary SearchSorting+2 |
| 3Sum Closest | Medium | 48.1% | 40.4% | ArrayTwo PointersSorting |
| Best Time to Buy and Sell Stock II | Medium | 70.8% | 39.8% | ArrayDynamic ProgrammingGreedy |
| Combination Sum | Medium | 76.1% | 39.8% | ArrayBacktracking |
| Decode Ways | Medium | 37.6% | 39.8% | StringDynamic Programming |
| Two Sum II - Input Array Is Sorted | Medium | 64.6% | 39.6% | ArrayTwo PointersBinary Search |
| Populating Next Right Pointers in Each Node | Medium | 66.9% | 39.6% | Linked ListTreeDepth-First Search+2 |
| Rotate Array | Medium | 44.5% | 39.6% | ArrayMathTwo Pointers |
| Create Hello World Function | Easy | 82.0% | 38.3% | |
| Lowest Common Ancestor of a Binary Search Tree | Medium | 70.1% | 38.3% | TreeDepth-First SearchBinary Search Tree+1 |
| Merge Strings Alternately | Easy | 82.1% | 38.3% | Two PointersString |
| Longest Consecutive Sequence | Medium | 47.0% | 38.0% | ArrayHash TableUnion Find |
| 4Sum | Medium | 40.0% | 37.0% | ArrayTwo PointersSorting |
| Valid Sudoku | Medium | 64.2% | 37.0% | ArrayHash TableMatrix |
| Subsets II | Medium | 60.9% | 37.0% | ArrayBacktrackingBit Manipulation |
| Maximal Rectangle | Hard | 58.1% | 37.0% | ArrayDynamic ProgrammingStack+2 |
| Word Break II | Hard | 55.1% | 36.3% | ArrayHash TableString+4 |
| Permutations | Medium | 81.7% | 36.2% | ArrayBacktracking |
| Zigzag Conversion | Medium | 53.6% | 36.2% | String |
| Reverse Nodes in k-Group | Hard | 65.4% | 36.2% | Linked ListRecursion |
| Recyclable and Low Fat Products | Easy | 88.7% | 35.4% | Database |
| Design Tic-Tac-Toe | Medium | 58.7% | 35.4% | ArrayHash TableDesign+2 |
| Alien Dictionary | Hard | 37.1% | 35.4% | ArrayStringDepth-First Search+3 |
| Shortest Distance from All Buildings | Hard | 44.9% | 35.4% | ArrayBreadth-First SearchMatrix |
| Meeting Rooms II | Medium | 52.6% | 35.4% | ArrayTwo PointersGreedy+3 |
| Product of Array Except Self | Medium | 68.6% | 35.4% | ArrayPrefix Sum |
| Move Zeroes | Easy | 63.6% | 35.4% | ArrayTwo Pointers |
| Find K Closest Elements | Medium | 49.4% | 35.4% | ArrayTwo PointersBinary Search+3 |
| First Missing Positive | Hard | 42.5% | 35.4% | ArrayHash Table |
| Wildcard Matching | Hard | 31.4% | 35.4% | StringDynamic ProgrammingGreedy+1 |
| Combination Sum II | Medium | 59.0% | 34.5% | ArrayBacktracking |
| Unique Paths II | Medium | 44.2% | 34.5% | ArrayDynamic ProgrammingMatrix |
| Minimum Depth of Binary Tree | Easy | 52.4% | 34.5% | TreeDepth-First SearchBreadth-First Search+1 |
| Binary Tree Inorder Traversal | Easy | 79.7% | 34.5% | StackTreeDepth-First Search+1 |
| Jump Game II | Medium | 42.5% | 33.6% | ArrayDynamic ProgrammingGreedy |
| N-Queens | Hard | 75.0% | 33.6% | ArrayBacktracking |
| Search Insert Position | Easy | 50.7% | 33.6% | ArrayBinary Search |
| Construct Binary Tree from Preorder and Inorder Traversal | Medium | 68.4% | 33.6% | ArrayHash TableDivide and Conquer+2 |
| Rotate List | Medium | 41.2% | 32.6% | Linked ListTwo Pointers |
| Search in Rotated Sorted Array II | Medium | 39.8% | 32.6% | ArrayBinary Search |
| Reverse Linked List | Easy | 80.3% | 32.3% | Linked ListRecursion |
| Add Two Integers | Easy | 87.9% | 32.0% | Math |
| Shortest Path in a Hidden Grid | Medium | 44.5% | 32.0% | ArrayDepth-First SearchBreadth-First Search+2 |
| Interval List Intersections | Medium | 72.9% | 32.0% | ArrayTwo PointersLine Sweep |
| Range Sum Query - Immutable | Easy | 71.4% | 32.0% | ArrayDesignPrefix Sum |
| Frequency of the Most Frequent Element | Medium | 44.6% | 32.0% | ArrayBinary SearchGreedy+3 |
| Random Pick Index | Medium | 65.0% | 32.0% | Hash TableMathReservoir Sampling+1 |
| Kth Smallest Element in a BST | Medium | 76.5% | 32.0% | TreeDepth-First SearchBinary Search Tree+1 |
| Decode String | Medium | 62.3% | 32.0% | StringStackRecursion |
| Koko Eating Bananas | Medium | 49.7% | 32.0% | ArrayBinary Search |
| Goat Latin | Easy | 69.9% | 32.0% | String |
| Remove All Adjacent Duplicates in String II | Medium | 60.9% | 32.0% | StringStack |
| Best Time to Buy and Sell Stock III | Hard | 53.2% | 32.0% | ArrayDynamic Programming |
| Toeplitz Matrix | Easy | 69.7% | 32.0% | ArrayMatrix |
| Edit Distance | Medium | 60.2% | 31.6% | StringDynamic Programming |
| Maximum Depth of Binary Tree | Easy | 77.9% | 31.6% | TreeDepth-First SearchBreadth-First Search+1 |
| Reverse Linked List II | Medium | 51.0% | 31.6% | Linked List |
| Length of Last Word | Easy | 58.3% | 31.6% | String |
| Sudoku Solver | Hard | 65.4% | 30.6% | ArrayHash TableBacktracking+1 |
| Symmetric Tree | Easy | 60.8% | 30.6% | TreeDepth-First SearchBreadth-First Search+1 |
| Minimum Size Subarray Sum | Medium | 51.1% | 29.9% | ArrayBinary SearchSliding Window+1 |
| Course Schedule II | Medium | 55.0% | 29.9% | Depth-First SearchBreadth-First SearchGraph+1 |
| Max Points on a Line | Hard | 30.3% | 29.9% | ArrayHash TableMath+1 |
| Reverse Words in a String | Medium | 55.6% | 29.9% | Two PointersString |
| Pascal's Triangle | Easy | 78.7% | 27.9% | ArrayDynamic Programming |
| Restore IP Addresses | Medium | 55.3% | 26.9% | StringBacktracking |
| Longest Valid Parentheses | Hard | 38.1% | 26.9% | StringDynamic ProgrammingStack |
| Convert Sorted List to Binary Search Tree | Medium | 66.0% | 26.9% | Linked ListDivide and ConquerTree+2 |
| Swap Nodes in Pairs | Medium | 69.0% | 25.5% | Linked ListRecursion |
| Same Tree | Easy | 66.7% | 25.5% | TreeDepth-First SearchBreadth-First Search+1 |
| Integer to Roman | Medium | 70.5% | 25.5% | Hash TableMathString |
| Path Sum | Easy | 54.5% | 24.9% | TreeDepth-First SearchBreadth-First Search+1 |
| House Robber | Medium | 52.9% | 24.1% | ArrayDynamic Programming |
| Palindrome Partitioning | Medium | 73.7% | 24.1% | StringDynamic ProgrammingBacktracking |
| Find Minimum in Rotated Sorted Array | Medium | 53.8% | 24.1% | ArrayBinary Search |
| Single Number | Easy | 77.4% | 24.1% | ArrayBit Manipulation |
| Contains Duplicate | Easy | 64.1% | 24.1% | ArrayHash TableSorting |
| Combinations | Medium | 74.2% | 24.0% | Backtracking |
| Convert Sorted Array to Binary Search Tree | Easy | 75.2% | 22.3% | ArrayDivide and ConquerTree+2 |
| Balanced Binary Tree | Easy | 57.9% | 22.3% | TreeDepth-First SearchBinary Tree |
| Minimum Path Sum | Medium | 67.8% | 22.3% | ArrayDynamic ProgrammingMatrix |
| Path Sum II | Medium | 61.8% | 20.3% | BacktrackingTreeDepth-First Search+1 |
| Permutations II | Medium | 63.0% | 18.4% | ArrayBacktrackingSorting |
| Substring with Concatenation of All Words | Hard | 34.0% | 16.1% | Hash TableStringSliding Window |
| Unique Binary Search Trees II | Medium | 62.0% | 16.1% | Dynamic ProgrammingBacktrackingTree+2 |
| Flatten Binary Tree to Linked List | Medium | 70.2% | 15.8% | Linked ListStackTree+2 |
| Word Search II | Hard | 38.1% | 15.8% | ArrayStringBacktracking+2 |
| Pascal's Triangle II | Easy | 67.1% | 14.1% | ArrayDynamic Programming |
| Spiral Matrix II | Medium | 74.7% | 13.6% | ArrayMatrixSimulation |
| Evaluate Reverse Polish Notation | Medium | 57.1% | 10.2% | ArrayMathStack |
| Binary Tree Level Order Traversal II | Medium | 67.7% | 7.5% | TreeBreadth-First SearchBinary Tree |