by Adam Owada
Problems and solutions to Leetcode’s Top Interview 150 list. Problems come from Leetcode. Solutions with comments are generated by ChatGPT.
My goal with this repo is to learn and advance my abilities with data structures and algorithms. Lately I’ve noticed that when I solve Leetcode problems, even easy ones, I mistakenly believe I have the best, most optimal solution when in reality there are more efficient and elegant approaches I never thought of.
More alarming is that the approaches and techniques from these optimal solutions are applicable across a wide range of problems, and my solutions feel one-off and narrow. Ultimately this means I have much more to learn. Just getting a solution accepted on Leetcode isn’t enough to maximize growth and learning, I need to see the optimal solution and think about how it can be applied to novel problems.
| Merge Sorted Array | Easy | problem | solution |
| Remove Element | Easy | problem | solution |
| Remove Duplicates from Sorted Array | Easy | problem | solution |
| Remove Duplicates from Sorted Array II | Medium | problem | solution |
| Majority Element | Easy | problem | solution |
| Rotate Array | Medium | problem | solution |
| Best Time to Buy and Sell Stock | Easy | problem | solution |
| Best Time to Buy and Sell Stock II | Medium | problem | solution |
| Jump Game | Medium | problem | solution |
| Jump Game II | Medium | problem | solution |
| H-Index | Medium | problem | solution |
| Insert Delete GetRandom O(1) | Medium | problem | solution |
| Product of Array Except Self | Medium | problem | solution |
| Gas Station | Medium | problem | solution |
| Candy | Hard | problem | solution |
| Trapping Rain Water | Hard | problem | solution |
| Roman to Integer | Easy | problem | solution |
| Integer to Roman | Medium | problem | solution |
| Length of Last Word | Easy | problem | solution |
| Longest Common Prefix | Easy | problem | solution |
| Reverse Words in a String | Medium | problem | solution |
| Zigzag Conversion | Medium | problem | solution |
| Find the Index of the First Occurrence in a String | Easy | problem | solution |
| Text Justification | Hard | problem | solution |
| Valid Palindrome | Easy | problem | solution |
| Is Subsequence | Easy | problem | solution |
| Two Sum II - Input Array Is Sorted | Medium | problem | solution |
| Container With Most Water | Medium | problem | solution |
| 3Sum | Medium | problem | solution |
| Minimizing Size Subarray Sum | Medium | problem | solution |
| Longest Substring Without Repeating Characters | Medium | problem | solution |
| Substring with Concatenation of All Words | Hard | problem | solution |
| Minimum Window Substring | Hard | problem | solution |
| Valid Sudoku | Medium | problem | solution |
| Spiral Matrix | Medium | problem | solution |
| Rotate Image | Medium | problem | solution |
| Set Matrix Zeroes | Medium | problem | solution |
| Game of Life | Medium | problem | solution |
| Ransom Note | Easy | problem | solution |
| Isomorphic Strings | Easy | problem | solution |
| Word Pattern | Easy | problem | solution |
| Valid Anagram | Easy | problem | solution |
| Group Anagrams | Medium | problem | solution |
| Two Sum | Easy | problem | solution |
| Happy Number | Easy | problem | solution |
| Contains Duplicate II | Easy | problem | solution |
| Longest Consecutive Sequence | Medium | problem | solution |
| Summary Ranges | Easy | problem | solution |
| Merge Intervals | Medium | problem | solution |
| Insert Interval | Medium | problem | solution |
| Minimum Number of Arrows to Burst Balloons | Medium | problem | solution |
| Valid Parentheses | Easy | problem | solution |
| Simplify Path | Medium | problem | solution |
| Min Stack | Medium | problem | solution |
| Evaluate Reverse Polish Notation | Medium | problem | solution |
| Basic Calculator | Hard | problem | solution |