Problems
Pick a problem, write a solution, and run it against real testcases in a sandbox.
| Status | Title | Topics | Difficulty |
|---|---|---|---|
| 1. Two Sum | ArrayHash Table | Easy | |
| 3. Longest Substring Without Repeating Characters | Hash TableStringSliding Window | Medium | |
| 11. Container With Most Water | ArrayTwo PointersGreedy | Medium | |
| 14. Longest Common Prefix | StringTrie | Easy | |
| 20. Valid Parentheses | StringStack | Easy | |
| 32. Longest Valid Parentheses | StringDynamic ProgrammingStack | Hard | |
| 41. First Missing Positive | ArrayHash Table | Hard | |
| 42. Trapping Rain Water | ArrayTwo PointersStack | Hard | |
| 49. Group Anagrams | ArrayHash TableString | Medium | |
| 53. Maximum Subarray | ArrayDivide and ConquerDynamic Programming | Medium | |
| 56. Merge Intervals | ArraySorting | Medium | |
| 70. Climbing Stairs | MathDynamic ProgrammingMemoization | Easy | |
| 121. Best Time to Buy and Sell Stock | ArrayDynamic Programming | Easy | |
| 238. Product of Array Except Self | ArrayPrefix Sum | Medium | |
| 242. Valid Anagram | Hash TableStringSorting | Easy |