| LRU Cache ↗ | Medium | Hash Table, Linked List, Design | |
| Design Hit Counter ↗ | Medium | Array, Binary Search, Design | |
| Merge Intervals ↗ | Medium | Array, Sorting | |
| Course Schedule II ↗ | Medium | Depth-First Search, Breadth-First Search, Graph Theory | |
| Number of Islands ↗ | Medium | Array, Depth-First Search, Breadth-First Search | |
| Two Sum ↗ | Easy | Array, Hash Table | |
| Reverse Linked List ↗ | Easy | Linked List, Recursion | |
| Longest Common Prefix ↗ | Easy | Array, String, Trie | |
| Insert Delete GetRandom O(1) ↗ | Medium | Array, Hash Table, Math | |
| Basic Calculator II ↗ | Medium | Math, String, Stack | |
| Snapshot Array ↗ | Medium | Array, Hash Table, Binary Search | |
| Best Time to Buy and Sell Stock ↗ | Easy | Array, Dynamic Programming | |
| Reverse Integer ↗ | Medium | Math | |
| Subarray Sum Equals K ↗ | Medium | Array, Hash Table, Prefix Sum | |
| Group Anagrams ↗ | Medium | Array, Hash Table, String | |
| Valid Palindrome ↗ | Easy | Two Pointers, String | |
| Course Schedule ↗ | Medium | Depth-First Search, Breadth-First Search, Graph Theory | |
| Find First and Last Position of Element in Sorted Array ↗ | Medium | Array, Binary Search | |
| Subarray Product Less Than K ↗ | Medium | Array, Binary Search, Sliding Window | |
| 3Sum ↗ | Medium | Array, Two Pointers, Sorting | |
| Merge k Sorted Lists ↗ | Hard | Linked List, Divide and Conquer, Heap (Priority Queue) | |
| Meeting Rooms ↗ | Easy | Array, Sorting | |
| Spiral Matrix ↗ | Medium | Array, Matrix, Simulation | |
| Top K Frequent Elements ↗ | Medium | Array, Hash Table, Divide and Conquer | |
| Rotate Image ↗ | Medium | Array, Math, Matrix | |
| Edit Distance ↗ | Medium | String, Dynamic Programming | |
| Best Time to Buy and Sell Stock II ↗ | Medium | Array, Dynamic Programming, Greedy | |
| Word Ladder ↗ | Hard | Hash Table, String, Breadth-First Search | |
| Task Scheduler ↗ | Medium | Array, Hash Table, Greedy | |
| Valid Sudoku ↗ | Medium | Array, Hash Table, Matrix | |
| Time Based Key-Value Store ↗ | Medium | Hash Table, String, Binary Search | |
| Path Sum ↗ | Easy | Tree, Depth-First Search, Breadth-First Search | |
| Best Time to Buy and Sell Stock with Cooldown ↗ | Medium | Array, Dynamic Programming | |
| Brace Expansion ↗ | Medium | String, Backtracking, Stack | |
| Serialize and Deserialize N-ary Tree ↗ | Hard | String, Tree, Depth-First Search | |
| Total Hamming Distance ↗ | Medium | Array, Math, Bit Manipulation | |
| Longest Substring Without Repeating Characters ↗ | Medium | Hash Table, String, Sliding Window | |
| Longest Consecutive Sequence ↗ | Medium | Array, Hash Table, Union-Find | |
| Kth Largest Element in an Array ↗ | Medium | Array, Divide and Conquer, Sorting | |
| Rotate Array ↗ | Medium | Array, Math, Two Pointers | |