Got stuck in a LeetCode question? This repository will help you by providing approach of solving the problems from LeetCode platform.
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- There are new LeetCode questions every week. I'll keep updating for full summary and better solutions.
- For more challenging problem solutions, you can also see our HackerRank-Solutions, ProjectEuler repositories.
- Hope you enjoy the journey of learning data structures and algorithms.
- Notes: "🔒" means your subscription of LeetCode premium membership is required for reading the question.
- Bit Manipulation
- Array
- String
- Linked List
- Stack
- Queue
- Heap
- Tree
- Hash Table
- Math
- Two Pointers
- Sort
- Recursion
- Binary Search
- Binary Search Tree
- Breadth-First Search
- Depth-First Search
- Backtracking
- Dynamic Programming
- Greedy
- Graph
- Geometry
- Simulation
- Design
- Concurrency
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 0136 | Single Number | Java Python |
O(n) | O(1) | Easy | Using XOR | |
| 0137 | Single Number II | O(n) | O(1) | Medium | |||
| 0260 | Single Number III | Python | O(n) | O(1) | Medium |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 56 | Merge Intervals | Python | O(nlogn) | O(n) | Medium | Intervals | |
| 697 | Degree of an Array | Java | O(n) | O(n) | Easy | Array | |
| 697 | Duplicate Zeroes | JavaScript | O(n) | O(n) | Easy | Array |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 383 | Ransom Note | Java | O(1) | O(n) | Easy | Character Count | |
| 151 | Reverse Words in a String | Java | O(1) | O(n) | Medium |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 002 | Add Two Numbers | Java | O(n) | O(n) | Medium | Math |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 020 | Valid Parentheses | Python | O(n) | O(n) | Easy | Stack |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 103 | ZigZag Level Order | JavaScript | O(n) | O(n) | Medium | Binary Tree |
| # | Title | Solution | Time | Space | Difficulty | Tag | Video Explanation |
|---|---|---|---|---|---|---|---|
| 001 | Two Sum | Java Python |
O(N) | O(N) | Easy | ||
| 242 | Valid Anagram | Java | O(n) | O(1) | Easy | Tutorial | |
| 146 | LRU Cache | Java | Medium |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 5 | Longest Palindromic Substring | Python | O(N^2) | O(N) | Medium | Expand the Wings |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 204 | Count Primes | C++ | O(n(log(logn))) | O(n) | Easy | Math | |
| 168 | Excel Sheet Column Title | C++ | O(n) | O(n) | Easy | String | |
| 7 | Reverse Integer | C++ | O(n) | O(n) | Easy | Math |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 5 | Longest Palindromic Substring | Python | O(N^2) | O(N) | Medium | Expand the Wings |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 037 | Sudoku Solver | C++ | O(n^2) | O(1) | Hard | Hash Table |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 416 | Partition Equal Subset Sum | C++ | O(n^2) | O(n^2) | Medium | DP | |
| 56 | Wildcard Matching | Python | O(n^2) | O(n^2) | Hard |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 278 | First Bad Version | Java JavaScript |
O(logn) | O(1) | Easy | Binary Search | |
| 33 | Search in Rotated Sorted Array | Python | O(logn) | O(1) | Medium | Binary Search |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 1042 | Flower Planting with No Adjacent | Python | O(V+E) | O(2V+E) | Medium | Graph | Graph Coloring |
| Name | Country | Programming Language | Where to find you (add all links to your profiles eg on Hackerrank, Codechef, LeetCode...) |
|---|---|---|---|
Gourav R  |
India | Java | codedecks Hackerrank |
Lokendra Bohra  |
India | Python | Leetcode Hackerrank |
Yuri Spiridonov  |
Russia | Python | Twitter Leetcode Hackerrank |
Naveen Kashyap  |
India | Javascript | Twitter Leetcode |
Rudra Mishra  |
India | C++ | Twitter Leetcode |
Sachin Singh Negi  |
India | Python | Twitter Leetcode Hackerrrak |