1 | Two Sum | Easy |
3 | Longest Substring Without Repeating Characters | Medium |
18 | 4Sum | Medium |
30 | Substring with Concatenation of All Words | Hard |
36 | Valid Sudoku | Medium |
37 | Sudoku Solver | Hard |
49 | Group Anagrams | Medium |
76 | Minimum Window Substring | Hard |
85 | Maximal Rectangle | Hard |
94 | Binary Tree Inorder Traversal | Medium |
136 | Single Number | Easy |
138 | Copy List with Random Pointer | Medium |
149 | Max Points on a Line | Hard |
166 | Fraction to Recurring Decimal | Medium |
187 | Repeated DNA Sequences | Medium |
202 | Happy Number | Easy |
205 | Isomorphic Strings | Easy |
219 | Contains Duplicate II | Easy |
229 | Majority Element II | Medium |
242 | Valid Anagram | Easy |
268 | Missing Number | Easy |
290 | Word Pattern | Easy |
350 | Intersection of Two Arrays II | Easy |
380 | Insert Delete GetRandom O(1) | Medium |
381 | Insert Delete GetRandom O(1) - Duplicates allowed | Hard |
383 | Ransom Note | Easy |
387 | First Unique Character in a String | Easy |
389 | Find the Difference | Easy |
454 | 4Sum II | Medium |
496 | Next Greater Element I | Easy |