| Happy Number | Easy | 59.3% | 100.0% | Hash TableMathTwo Pointers |
| Course Schedule II | Medium | 55.0% | 96.3% | Depth-First SearchBreadth-First SearchGraph Theory+1 |
| Parallel Courses III | Hard | 66.8% | 92.8% | ArrayDynamic ProgrammingGraph Theory+1 |
| Design In-Memory File System | Hard | 48.4% | 92.8% | Hash TableStringDesign+2 |
| Minimum Window Substring | Hard | 47.0% | 90.9% | Hash TableStringSliding Window |
| Word Search II | Hard | 38.1% | 89.8% | ArrayStringBacktracking+2 |
| Trapping Rain Water | Hard | 66.8% | 86.4% | ArrayTwo PointersDynamic Programming+2 |
| Painting the Walls | Hard | 48.9% | 85.1% | ArrayDynamic Programming |
| Throne Inheritance | Medium | 66.9% | 83.7% | Hash TableTreeDepth-First Search+1 |
| Calculate Amount Paid in Taxes | Easy | 69.0% | 82.3% | ArraySimulation |
| Step-By-Step Directions From a Binary Tree Node to Another | Medium | 56.4% | 82.3% | StringTreeDepth-First Search+1 |
| Find All Anagrams in a String | Medium | 53.3% | 80.7% | Hash TableStringSliding Window |
| Maximum Number of Upgradable Servers | Medium | 43.2% | 80.7% | ArrayMathBinary Search |
| Maximum Profit in Job Scheduling | Hard | 54.6% | 79.1% | ArrayBinary SearchDynamic Programming+1 |
| Count Vowel Substrings of a String | Easy | 72.9% | 77.3% | Hash TableString |
| String Transformation | Hard | 26.7% | 75.3% | MathStringDynamic Programming+1 |
| Find the Maximum Length of a Good Subsequence I | Medium | 32.5% | 75.3% | ArrayHash TableDynamic Programming |
| Minimum Array Length After Pair Removals | Medium | 27.1% | 75.3% | ArrayHash TableTwo Pointers+3 |
| Find the Maximum Length of a Good Subsequence II | Hard | 25.1% | 73.2% | ArrayHash TableDynamic Programming |
| Number of Ways to Form a Target String Given a Dictionary | Hard | 56.6% | 70.8% | ArrayStringDynamic Programming |
| Merge k Sorted Lists | Hard | 58.9% | 70.8% | Linked ListDivide and ConquerHeap (Priority Queue)+1 |
| Parallel Courses | Medium | 62.1% | 68.2% | Graph TheoryTopological Sort |
| Course Schedule | Medium | 50.8% | 68.2% | Depth-First SearchBreadth-First SearchGraph Theory+1 |
| Minimum Absolute Difference Between Two Values | Easy | | 68.2% | ArrayEnumeration |
| Max Area of Island | Medium | 73.8% | 65.2% | ArrayDepth-First SearchBreadth-First Search+2 |
| Design HashMap | Easy | 66.4% | 65.2% | ArrayHash TableLinked List+2 |
| Two Sum | Easy | 57.1% | 65.2% | ArrayHash Table |
| Shortest Word Distance | Easy | 66.2% | 61.7% | ArrayString |
| Boundary of Binary Tree | Medium | 47.9% | 61.7% | TreeDepth-First SearchBinary Tree |
| Top K Frequent Elements | Medium | 65.9% | 61.7% | ArrayHash TableDivide and Conquer+5 |
| Maximum Number of Events That Can Be Attended | Medium | 38.9% | 61.7% | ArrayGreedySorting+1 |
| Simplify Path | Medium | 50.0% | 61.7% | StringStack |
| Basic Calculator | Hard | 46.6% | 61.7% | MathStringStack+1 |
| Web Crawler | Medium | 68.8% | 57.6% | StringDepth-First SearchBreadth-First Search+1 |
| Design Add and Search Words Data Structure | Medium | 48.2% | 57.6% | StringDepth-First SearchDesign+1 |
| Time Based Key-Value Store | Medium | 49.7% | 57.6% | Hash TableStringBinary Search+1 |
| Maximize Distance to Closest Person | Medium | 49.6% | 57.6% | Array |
| Remove Sub-Folders from the Filesystem | Medium | 78.6% | 57.6% | ArrayStringDepth-First Search+1 |
| LRU Cache | Medium | 46.8% | 57.6% | Hash TableLinked ListDesign+1 |
| Design Hit Counter | Medium | 69.6% | 57.6% | ArrayBinary SearchDesign+2 |
| Copy List with Random Pointer | Medium | 62.4% | 57.6% | Hash TableLinked List |
| Merge Two Sorted Lists | Easy | 68.0% | 57.6% | Linked ListRecursion |
| Task Scheduler | Medium | 62.7% | 57.6% | ArrayHash TableGreedy+3 |
| Web Crawler Multithreaded | Medium | 51.0% | 57.6% | Depth-First SearchBreadth-First SearchConcurrency |
| Keys and Rooms | Medium | 75.5% | 52.7% | Depth-First SearchBreadth-First SearchGraph Theory |
| Regular Expression Matching | Hard | 30.5% | 52.7% | StringDynamic ProgrammingRecursion |
| Min Stack | Medium | 57.7% | 52.7% | StackDesign |
| Insert Delete GetRandom O(1) | Medium | 55.3% | 52.7% | ArrayHash TableMath+2 |
| Design Log Storage System | Medium | 59.3% | 52.7% | Hash TableStringDesign+1 |
| Single Element in a Sorted Array | Medium | 59.2% | 52.7% | ArrayBinary Search |
| Maximum Number of Events That Can Be Attended II | Hard | 63.6% | 52.7% | ArrayBinary SearchDynamic Programming+1 |
| Snapshot Array | Medium | 36.7% | 52.7% | ArrayHash TableBinary Search+1 |
| Most Frequent IDs | Medium | 42.5% | 46.3% | ArrayHash TableHeap (Priority Queue)+1 |
| Graph Valid Tree | Medium | 49.8% | 46.3% | Depth-First SearchBreadth-First SearchUnion-Find+1 |
| Design Circular Deque | Medium | 64.4% | 46.3% | ArrayLinked ListDesign+1 |
| Making A Large Island | Hard | 56.3% | 46.3% | ArrayDepth-First SearchBreadth-First Search+2 |
| Populating Next Right Pointers in Each Node | Medium | 66.9% | 46.3% | Linked ListTreeDepth-First Search+2 |
| Integer to English Words | Hard | 34.8% | 46.3% | MathStringRecursion |
| Random Pick with Weight | Medium | 48.9% | 46.3% | ArrayMathBinary Search+2 |
| Leaf-Similar Trees | Easy | 70.2% | 46.3% | TreeDepth-First SearchBinary Tree |
| Longest Univalue Path | Medium | 43.6% | 46.3% | TreeDepth-First SearchBinary Tree |
| Reverse Only Letters | Easy | 68.2% | 46.3% | Two PointersString |
| Most Stones Removed with Same Row or Column | Medium | 62.7% | 46.3% | Hash TableDepth-First SearchUnion-Find+1 |
| Roman to Integer | Easy | 66.3% | 46.3% | Hash TableMathString |
| Cheapest Flights Within K Stops | Medium | 41.4% | 46.3% | Dynamic ProgrammingDepth-First SearchBreadth-First Search+3 |
| Rotting Oranges | Medium | 58.2% | 46.3% | ArrayBreadth-First SearchMatrix |
| Parallel Courses II | Hard | 30.6% | 46.3% | Dynamic ProgrammingBit ManipulationGraph Theory+1 |
| Campus Bikes | Medium | 59.1% | 46.3% | ArraySortingHeap (Priority Queue) |
| Possible Bipartition | Medium | 52.4% | 37.4% | Depth-First SearchBreadth-First SearchUnion-Find+1 |
| Design Browser History | Medium | 78.2% | 37.4% | ArrayLinked ListStack+3 |
| Populating Next Right Pointers in Each Node II | Medium | 57.1% | 37.4% | Linked ListTreeDepth-First Search+2 |
| Basic Calculator II | Medium | 46.7% | 37.4% | MathStringStack |
| Maximum Number of Removable Characters | Medium | 46.9% | 37.4% | ArrayTwo PointersString+1 |
| Container With Most Water | Medium | 59.6% | 37.4% | ArrayTwo PointersGreedy |
| Find Median from Data Stream | Hard | 54.2% | 37.4% | Two PointersDesignSorting+2 |
| Construct Binary Tree from Preorder and Inorder Traversal | Medium | 68.4% | 37.4% | ArrayHash TableDivide and Conquer+2 |
| Best Time to Buy and Sell Stock | Easy | 56.4% | 37.4% | ArrayDynamic Programming |
| Most Profitable Path in a Tree | Medium | 67.3% | 37.4% | ArrayTreeDepth-First Search+2 |
| N-Queens II | Hard | 78.2% | 37.4% | Backtracking |
| Valid Word Abbreviation | Easy | 37.0% | 37.4% | Two PointersString |
| Implement Trie (Prefix Tree) | Medium | 69.2% | 37.4% | Hash TableStringDesign+1 |
| Walls and Gates | Medium | 63.8% | 37.4% | ArrayBreadth-First SearchMatrix |
| Path With Minimum Effort | Medium | 62.8% | 37.4% | ArrayBinary SearchDepth-First Search+4 |
| Remove K Digits | Medium | 36.4% | 37.4% | StringStackGreedy+1 |
| Non-overlapping Intervals | Medium | 56.7% | 37.4% | ArrayDynamic ProgrammingGreedy+1 |
| Boats to Save People | Medium | 61.4% | 37.4% | ArrayTwo PointersGreedy+1 |
| Alert Using Same Key-Card Three or More Times in a One Hour Period | Medium | 46.1% | 37.4% | ArrayHash TableString+1 |
| Word Search | Medium | 46.9% | 37.4% | ArrayStringBacktracking+2 |
| My Calendar I | Medium | 58.2% | 37.4% | ArrayBinary SearchDesign+2 |
| Design Circular Queue | Medium | 54.0% | 37.4% | ArrayLinked ListDesign+1 |
| Meeting Rooms II | Medium | 52.6% | 37.4% | ArrayTwo PointersGreedy+3 |
| Paint Fence | Medium | 48.3% | 37.4% | Dynamic Programming |
| Design File System | Medium | 65.1% | 37.4% | Hash TableStringDesign+1 |
| Encode and Decode Strings | Medium | 51.2% | 37.4% | ArrayStringDesign |
| Add Two Numbers | Medium | 48.0% | 37.4% | Linked ListMathRecursion |
| Jump Game II | Medium | 42.5% | 37.4% | ArrayDynamic ProgrammingGreedy |
| The Maze | Medium | 60.3% | 37.4% | ArrayDepth-First SearchBreadth-First Search+1 |
| Count Nodes Equal to Average of Subtree | Medium | 86.7% | 37.4% | TreeDepth-First SearchBinary Tree |
| Height of Binary Tree After Subtree Removal Queries | Hard | 54.9% | 37.4% | ArrayTreeDepth-First Search+2 |
| Number of Islands | Medium | 63.8% | 37.4% | ArrayDepth-First SearchBreadth-First Search+2 |