| Trapping Rain Water | Hard | 66.8% | 100.0% | ArrayTwo PointersDynamic Programming+2 |
| Merge Intervals | Medium | 51.2% | 100.0% | ArraySorting |
| Tweet Counts Per Frequency | Medium | 45.9% | 100.0% | Hash TableStringBinary Search+3 |
| LRU Cache | Medium | 46.8% | 100.0% | Hash TableLinked ListDesign+1 |
| Flatten Nested List Iterator | Medium | 65.6% | 100.0% | StackTreeDepth-First Search+3 |
| Implement Trie (Prefix Tree) | Medium | 69.2% | 97.3% | Hash TableStringDesign+1 |
| Insert Delete GetRandom O(1) | Medium | 55.3% | 97.3% | ArrayHash TableMath+2 |
| Design Twitter | Medium | 44.2% | 97.3% | Hash TableLinked ListDesign+1 |
| Binary Gap | Easy | 74.1% | 97.3% | Bit Manipulation |
| Regular Expression Matching | Hard | 30.5% | 97.3% | StringDynamic ProgrammingRecursion |
| Integer to Roman | Medium | 70.5% | 97.3% | Hash TableMathString |
| Word Break II | Hard | 55.1% | 97.3% | ArrayHash TableString+4 |
| Alien Dictionary | Hard | 37.1% | 97.3% | ArrayStringDepth-First Search+3 |
| Time Needed to Buy Tickets | Easy | 72.2% | 97.3% | ArrayQueueSimulation |
| Valid Parentheses | Easy | 43.7% | 97.3% | StringStack |
| Max Points on a Line | Hard | 30.3% | 97.3% | ArrayHash TableMath+1 |
| Merge k Sorted Lists | Hard | 58.9% | 97.3% | Linked ListDivide and ConquerHeap (Priority Queue)+1 |
| Trapping Rain Water II | Hard | 64.0% | 97.3% | ArrayBreadth-First SearchHeap (Priority Queue)+1 |
| Finding the Users Active Minutes | Medium | 80.8% | 97.3% | ArrayHash Table |
| One Edit Distance | Medium | 34.6% | 97.3% | Two PointersString |
| Invalid Tweets | Easy | 85.2% | 97.3% | Database |
| Best Meeting Point | Hard | 61.4% | 97.3% | ArrayMathSorting+1 |
| Multiply Strings | Medium | 43.6% | 97.3% | MathStringSimulation |
| Wildcard Matching | Hard | 31.4% | 97.3% | StringDynamic ProgrammingGreedy+1 |
| Minimum Genetic Mutation | Medium | 56.4% | 97.3% | Hash TableStringBreadth-First Search |
| Design Skiplist | Hard | 59.5% | 97.3% | Linked ListDesign |
| Permutation Sequence | Hard | 52.2% | 97.3% | MathRecursion |
| Minimum Number of Steps to Make Two Strings Anagram | Medium | 82.5% | 97.3% | Hash TableStringCounting |
| Number of Connected Components in an Undirected Graph | Medium | 64.8% | 97.3% | Depth-First SearchBreadth-First SearchUnion-Find+1 |
| Count Student Number in Departments | Medium | 60.0% | 97.3% | Database |
| Rectangles Area | Medium | 68.7% | 97.3% | Database |
| Investments in 2016 | Medium | 50.8% | 97.3% | Database |
| Happy Number | Easy | 59.3% | 97.3% | Hash TableMathTwo Pointers |
| Customer Placing the Largest Number of Orders | Easy | 64.3% | 97.3% | Database |
| Number of Black Blocks | Medium | 41.5% | 97.3% | ArrayHash TableEnumeration |
| Reverse Linked List | Easy | 80.3% | 97.3% | Linked ListRecursion |
| Validate IP Address | Medium | 28.2% | 97.3% | String |
| The Skyline Problem | Hard | 45.0% | 97.3% | ArrayDivide and ConquerBinary Indexed Tree+5 |
| Masking Personal Information | Medium | 54.1% | 97.3% | String |
| Process Tasks Using Servers | Medium | 42.0% | 97.3% | ArrayHeap (Priority Queue) |
| Tree Node | Medium | 75.2% | 97.3% | Database |
| Remove All Occurrences of a Substring | Medium | 78.4% | 97.3% | StringStackSimulation |
| Lowest Common Ancestor of a Binary Search Tree | Medium | 70.1% | 97.3% | TreeDepth-First SearchBinary Search Tree+1 |
| Design Authentication Manager | Medium | 58.4% | 97.3% | Hash TableLinked ListDesign+1 |
| Count Sub Islands | Medium | 73.0% | 97.3% | ArrayDepth-First SearchBreadth-First Search+2 |
| Pascal's Triangle | Easy | 78.7% | 97.3% | ArrayDynamic Programming |
| Minimum Elements to Add to Form a Given Sum | Medium | 45.0% | 97.3% | ArrayGreedy |
| Kth Smallest Element in a Sorted Matrix | Medium | 64.4% | 97.3% | ArrayBinary SearchSorting+2 |
| Flatten 2D Vector | Medium | 50.4% | 97.3% | ArrayTwo PointersDesign+1 |
| Largest Plus Sign | Medium | 49.1% | 63.4% | ArrayDynamic Programming |
| Minimum Cost to Connect Sticks | Medium | 71.8% | 52.1% | ArrayGreedyHeap (Priority Queue) |
