This repository documents my journey through the NeetCode 150 problem set, designed to comprehensively prepare for technical interviews . Each problem is solved with multiple approaches, focusing on optimal time and space complexity.
- 🏆 Comprehensive Coverage: Includes all 150 problems categorized by topic.
- 📂 Well-Organized: Each problem is classified under relevant categories for easy navigation.
- 🚀 Practical Solutions: Solutions written in C, C++,and Python, and others.
- 📈 Progress Tracking: Keep tabs on solved problems, My SpreedSheet, (you can copy).
- 🎯 Targeted Practice: From basic concepts to advanced problems.
- ✅ 🧮 Arrays & Hashing (0/9)
- ❎ 🔄 Two Pointers (0/5)
- ❎ 📚 Stack (0/7)
- ❎ 🚪 Sliding Window (0/6)
- ❎ 🔍 Binary Search (0/7)
- ❎ 🔗 Linked List (0/11)
- ❎ 🌳 Trees (0/15)
- ❎ 🧵 Tries (0/3)
- ❎ 🔑 Heap / Priority Queue (0/7)
- ❎ 🔑 Backtracking (0/9)
- ❎ 🗺️ Graphs (0/13)
- ❎ 🌐 Advanced Graphs (0/6)
- ❎ 🏃 1D Dynamic Programming (0/12)
- ❎ 🏗️ 2D Dynamic Programming (0/11)
- ❎ 🏆 Greedy (0/8)
- ❎ 🕒 Intervals (0/6)
- ❎ 📐 Math & Geometry (0/8)
- ❎ 💡 Bit Manipulation (0/7)
- Problem Understanding: Deeply analyze problem constraints
- Multiple Solutions: Implement brute force, optimized, and most optimal solutions
- Complexity Analysis: Detailed time and space complexity for each approach
- Explanatory Comments: Thorough code commenting explaining logic
- Time Complexity: O(n) or better
- Space Complexity: O(1) when possible
- Edge Case Handling: Comprehensive testing
- Code Readability: Clean, modular solutions
- Clone this repository:
git clone https://github.com/yomazini/NeetCode-150-Solutions.git
- Navigate to the problem category:
cd Arrays_and_Hashing - Run the solution in your preferred programming language:
# if Python python3 solution.py# if C run it with gcc gcc main.c# if C++ run it with g g++ main.cpp
Tracking my learning journey, algorithmic thinking, and problem-solving skills through systematic practice.
Below is a categorized list of all the problems. Click on a problem to visit it on LeetCode.
| Problem | Link |
|---|---|
| Contains Duplicate | Link |
| Valid Anagram | Link |
| Two Sum | Link |
| Group Anagrams | Link |
| Top K Frequent Elements | Link |
| Product of Array Except Self | Link |
| Valid Sudoku | Link |
| Encode and Decode Strings | Link |
| Longest Consecutive Sequence | Link |
| Problem | Link |
|---|---|
| Valid Palindrome | Link |
| Two Sum II | Link |
| 3Sum | Link |
| Container with Most Water | Link |
| Trapping Rain Water | Link |
| Problem | Link |
|---|---|
| Best Time to Buy & Sell Stock | Link |
| Longest Substring Without Repeating Characters | Link |
| Longest Repeating Character Replacement | Link |
| Permutation in String | Link |
| Minimum Window Substring | Link |
| Problem | Link |
|---|---|
| Valid Parentheses | Link |
| Min Stack | Link |
| Evaluate Reverse Polish Notation | Link |
| Generate Parentheses | Link |
| Daily Temperatures | Link |
| Car Fleet | Link |
| Largest Rectangle in Histogram | Link |
| Problem | Link |
|---|---|
| Binary Search | Link |
| Search a 2D Matrix | Link |
| Koko Eating Bananas | Link |
| Search Rotated Sorted Array | Link |
| Find Minimum in Rotated Sorted Array | Link |
| Time Based Key-Value Store | Link |
| Find Median of Two Sorted Arrays | Link |
| Problem | Link |
|---|---|
| Reverse Linked List | Link |
| Merge Two Linked Lists | Link |
| Reorder List | Link |
| Remove Nth Node from End of List | Link |
| Copy List with Random Pointer | Link |
| Add Two Numbers | Link |
| Linked List Cycle | Link |
| Find the Duplicate Number | Link |
| LRU Cache | Link |
| Merge K Sorted Lists | Link |
| Reverse Nodes in K-Group | Link |
| Problem | Link |
|---|---|
| Invert Binary Tree | Link |
| Maximum Depth of Binary Tree | Link |
| Diameter of a Binary Tree | Link |
| Balanced Binary Tree | Link |
| Same Tree | Link |
| Subtree of Another Tree | Link |
| Lowest Common Ancestor of a BST | Link |
| Binary Tree Level Order Traversal | Link |
| Binary Tree Right Side View | Link |
| Count Good Nodes in a Binary Tree | Link |
| Validate Binary Search Tree | Link |
| Kth Smallest Element in a BST | Link |
| Construct Tree from Preorder and Inorder Traversal | Link |
| Binary Tree Max Path Sum | Link |
| Serialize and Deserialize Binary Tree | Link |
| Problem | Link |
|---|---|
| Implement Trie | Link |
| Design Add and Search Word Data Structure | Link |
| Word Search II | Link |
| Problem | Link |
|---|---|
| Kth Largest Element in a Stream | Link |
| Last Stone Weight | Link |
| K Closest Points to Origin | Link |
| Kth Largest Element in an Array | Link |
| Task Scheduler | Link |
| Design Twitter | Link |
| Find Median from Data Stream | Link |
| Problem | Link |
|---|---|
| Subsets | Link |
| Combination Sum | Link |
| Permutations | Link |
| Subsets II | Link |
| Combination Sum II | Link |
| Word Search | Link |
| Palindrome Partitioning | Link |
| Letter Combinations of a Phone Number | Link |
| N-Queens | Link |
| Problem | Link |
|---|---|
| Number of Islands | Link |
| Clone Graph | Link |
| Max Area of Island | Link |
| Pacific Atlantic Waterflow | Link |
| Surrounded Regions | Link |
| Rotting Oranges | Link |
| Walls and Gates | Link |
| Course Schedule | Link |
| Course Schedule II | Link |
| Redundant Connection | Link |
| Number of Connected Components in Graph | Link |
| Graph Valid Tree | Link |
| Word Ladder | Link |
| Problem | Link |
|---|---|
| Reconstruct Itinerary | Link |
| Min Cost to Connect all Points | Link |
| Network Delay Time | Link |
| Swim in Rising Water | Link |
| Alien Dictionary | Link |
| Cheapest Flights with K Stops | Link |
| Problem | Link |
|---|---|
| Climbing Stairs | Link |
| Min Cost Climbing Stairs | Link |
| House Robber | Link |
| House Robber II | Link |
| Longest Palindromic Substring | Link |
| Palindrome Substrings | Link |
| Decode Ways | Link |
| Coin Change | Link |
| Maximum Product Subarray | Link |
| Word Break | Link |
| Longest Increasing Subsequence | Link |
| Partition Equal Subset Sum | Link |
| Problem | Link |
|---|---|
| Unique Paths | Link |
| Longest Common Subsequence | Link |
| Best Time to Buy/Sell Stock With Cooldown | Link |
| Coin Change II | Link |
| Target Sum | Link |
| Interleaving String | Link |
| Longest Increasing Path in a Matrix | Link |
| Distinct Subsequences | Link |
| Edit Distance | Link |
| Burst Balloons | Link |
| Regular Expression Matching | Link |
| Problem | Link |
|---|---|
| Maximum Subarray | Link |
| Jump Game | Link |
| Jump Game II | Link |
| Gas Station | Link |
| Hand of Straights | Link |
| Merge Triplets to Form Target Triplet | Link |
| Partition Labels | Link |
| Valid Parenthesis String | Link |
| Problem | Link |
|---|---|
| Insert Interval | Link |
| Merge Intervals | Link |
| Non-Overlapping Intervals | Link |
| Meeting Rooms | Link |
| Meeting Rooms II | Link |
| Minimum Interval to Include Each Query | Link |
| Problem | Link |
|---|---|
| Rotate Image | Link |
| Spiral Matrix | Link |
| Set Matrix Zeroes | Link |
| Happy Number | Link |
| Plus One | Link |
| Pow(x, n) | Link |
| Multiply Strings | Link |
| Detect Squares | Link |
| Problem | Link |
|---|---|
| Single Number | Link |
| Number of 1 Bits | Link |
| Counting Bits | Link |
| Reverse Bits | Link |
| Missing Number | Link |
| Sum of Two Integers | Link |
| Reverse Integer | Link |
Disclaimer: Solutions are for learning purposes. Always strive to understand the underlying concepts!
Made with ☕️ and ☕️☕️☕️ by Youssef Mazini (ymazini)
Open to discussions, alternative solutions, and optimization suggestions. Feel free to open an issue or submit a pull request!