| Two Sum ↗ | Easy | Array, Hash Table | |
| Add Two Numbers ↗ | Medium | Linked List, Math, Recursion | |
| Palindrome Number ↗ | Easy | Math | |
| Longest Common Prefix ↗ | Easy | Array, String, Trie | |
| Best Time to Buy and Sell Stock ↗ | Easy | Array, Dynamic Programming | |
| Concatenation of Array ↗ | Easy | Array, Simulation | |
| Longest Substring Without Repeating Characters ↗ | Medium | Hash Table, String, Sliding Window | |
| Trapping Rain Water ↗ | Hard | Array, Two Pointers, Dynamic Programming | |
| Longest Palindromic Substring ↗ | Medium | Two Pointers, String, Dynamic Programming | |
| Median of Two Sorted Arrays ↗ | Hard | Array, Binary Search, Divide and Conquer | |
| 3Sum ↗ | Medium | Array, Two Pointers, Sorting | |
| Container With Most Water ↗ | Medium | Array, Two Pointers, Greedy | |
| Longest Consecutive Sequence ↗ | Medium | Array, Hash Table, Union-Find | |
| Roman to Integer ↗ | Easy | Hash Table, Math, String | |
| Majority Element ↗ | Easy | Array, Hash Table, Divide and Conquer | |
| Reverse Integer ↗ | Medium | Math | |
| Maximum Subarray ↗ | Medium | Array, Divide and Conquer, Dynamic Programming | |
| Valid Parentheses ↗ | Easy | String, Stack | |
| Merge Intervals ↗ | Medium | Array, Sorting | |
| Subarray Sum Equals K ↗ | Medium | Array, Hash Table, Prefix Sum | |
| Remove Duplicates from Sorted Array ↗ | Easy | Array, Two Pointers | |
| Merge Sorted Array ↗ | Easy | Array, Two Pointers, Sorting | |
| Combine Two Tables ↗ | Easy | Database | |
| Create Hello World Function ↗ | Easy | | |
| Number of Islands ↗ | Medium | Array, Depth-First Search, Breadth-First Search | |
| Spiral Matrix ↗ | Medium | Array, Matrix, Simulation | |
| Koko Eating Bananas ↗ | Medium | Array, Binary Search | |
| Valid Anagram ↗ | Easy | Hash Table, String, Sorting | |
| Top K Frequent Elements ↗ | Medium | Array, Hash Table, Divide and Conquer | |
| Kth Largest Element in an Array ↗ | Medium | Array, Divide and Conquer, Sorting | |
| Next Permutation ↗ | Medium | Array, Two Pointers | |
| Group Anagrams ↗ | Medium | Array, Hash Table, String | |
| Merge Two Sorted Lists ↗ | Easy | Linked List, Recursion | |
| Search in Rotated Sorted Array ↗ | Medium | Array, Binary Search | |
| N-Queens ↗ | Hard | Array, Backtracking | |
| LRU Cache ↗ | Medium | Hash Table, Linked List, Design | |
| Reverse Linked List ↗ | Easy | Linked List, Recursion | |
| Merge Strings Alternately ↗ | Easy | Two Pointers, String | |
| Move Zeroes ↗ | Easy | Array, Two Pointers | |
| Can Make Arithmetic Progression From Sequence ↗ | Easy | Array, Sorting | |