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🚨 NEW: NeetCode 150 & Blind 75 Essential Problems + System Design Guide and Latest FAANG Questions! 🚨
A curated collection of coding and system design questions asked at top tech companies. Helping you ace your next interview!
- NeetCode 150 - Essential Problems for FAANG Interviews ⭐ NEW!
- Blind 75 - The Ultimate Interview Preparation List ⭐ NEW!
- Top 75 LeetCode Questions to Crack The Coding Interviews
- LLM Papers Cheatsheet for Beginners and Experts - Essential Research Papers for LLMs
- Complete Machine Learning Interview Preparation Guide for Beginners to Experts
| SNo. | Contents |
|---|---|
| 1. | FAANG Must Do Problems |
| 2. | Amazon |
| 3. | Microsoft |
| 4. | Meta (Facebook) |
| 5. | Google Top 50 |
| 6. | |
| 7. | |
| 8. | Flipkart |
| 9. | Netflix |
| 10. | OpenAI |
| 11. | Databricks |
| 12. | Machine Learning & AI Resources |
- Start with Blind 75 for fundamentals
- Practice 2-3 problems daily focusing on patterns
- Review Python Resources for clean code
- Complete NeetCode 150 for comprehensive coverage
- Focus on Recent FAANG Questions
- Start System Design preparation
- Review company-specific sections below
- Practice ML Interview Questions for ML roles
- Study AI/LLM Papers for cutting-edge roles
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Two Sum | Easy | O(n) | O(n) |
| 2 | Longest Substring Without Repeating Characters | Medium | O(n) | O(min(m,n)) |
| 3 | Longest Palindromic Substring | Medium | O(n²) | O(1) |
| 4 | Container With Most Water | Medium | O(n) | O(1) |
| 5 | 3Sum | Medium | O(n²) | O(1) |
| 6 | Remove Nth Node From End of List | Medium | O(n) | O(1) |
| 7 | Valid Parentheses | Easy | O(n) | O(n) |
| 8 | Merge Two Sorted Lists | Easy | O(n+m) | O(1) |
| 9 | Merge k Sorted Lists | Hard | O(n log k) | O(1) |
| 10 | Search in Rotated Sorted Array | Medium | O(log n) | O(1) |
| 11 | Combination Sum | Medium | O(2ⁿ) | O(n) |
| 12 | Rotate Image | Medium | O(n²) | O(1) |
| 13 | Group Anagrams | Medium | O(n k log k) | O(n k) |
| 14 | Maximum Subarray | Easy | O(n) | O(1) |
| 15 | Spiral Matrix | Medium | O(m×n) | O(1) |
| 16 | Jump Game | Medium | O(n) | O(1) |
| 17 | Merge Intervals | Medium | O(n log n) | O(n) |
| 18 | Insert Interval | Medium | O(n) | O(n) |
| 19 | Unique Paths | Medium | O(m×n) | O(m×n) |
| 20 | Climbing Stairs | Easy | O(n) | O(1) |
| 21 | Set Matrix Zeroes | Medium | O(m×n) | O(1) |
| 22 | Minimum Window Substring | Hard | O(n) | O(k) |
| 23 | Word Search | Medium | O(m×n×4ᵏ) | O(k) |
| 24 | Decode Ways | Medium | O(n) | O(n) |
| 25 | Validate Binary Search Tree | Medium | O(n) | O(h) |
| 26 | Same Tree | Easy | O(n) | O(h) |
| 27 | Binary Tree Level Order Traversal | Medium | O(n) | O(n) |
| 28 | Maximum Depth of Binary Tree | Easy | O(n) | O(h) |
| 29 | Construct Binary Tree from Preorder and Inorder Traversal | Medium | O(n) | O(n) |
| 30 | Best Time to Buy and Sell Stock | Easy | O(n) | O(1) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Two Sum | Easy | O(n) | O(n) |
| 2 | Add Two Numbers | Medium | O(max(m,n)) | O(max(m,n)) |
| 3 | Longest Substring Without Repeating Characters | Medium | O(n) | O(min(m,n)) |
| 4 | Median of Two Sorted Arrays | Hard | O(log(min(m,n))) | O(1) |
| 5 | Longest Palindromic Substring | Medium | O(n²) | O(1) |
| 6 | ZigZag Conversion | Medium | O(n) | O(n) |
| 7 | String to Integer (atoi) | Medium | O(n) | O(1) |
| 8 | 3Sum | Medium | O(n²) | O(1) or O(n) |
| 9 | Letter Combinations of a Phone Number | Medium | O(4ⁿ) | O(n) |
| 10 | Valid Parentheses | Easy | O(n) | O(n) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Two Sum | Easy | O(n) | O(n) |
| 2 | Add Two Numbers | Medium | O(max(m,n)) | O(max(m,n)) |
| 3 | Median of Two Sorted Arrays | Hard | O(log(min(m,n))) | O(1) |
| 4 | Longest Palindromic Substring | Medium | O(n²) | O(1) |
| 5 | String to Integer (atoi) | Medium | O(n) | O(1) |
| 6 | Roman to Integer | Easy | O(n) | O(1) |
| 7 | 3Sum | Medium | O(n²) | O(1) or O(n) |
| 8 | Valid Parentheses | Easy | O(n) | O(n) |
| 9 | Merge Two Sorted Lists | Easy | O(n+m) | O(1) |
| 10 | Merge k Sorted Lists | Hard | O(n log k) | O(1) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Regular Expression Matching | Hard | O(m×n) | O(m×n) |
| 2 | Roman to Integer | Easy | O(n) | O(1) |
| 3 | 3Sum | Medium | O(n²) | O(1) or O(n) |
| 4 | Letter Combinations of a Phone Number | Medium | O(4ⁿ) | O(n) |
| 5 | Valid Parentheses | Easy | O(n) | O(n) |
| 6 | Merge k Sorted Lists | Hard | O(n log k) | O(1) |
| 7 | Reverse Nodes in k-Group | Hard | O(n) | O(1) |
| 8 | Remove Duplicates from Sorted Array | Easy | O(n) | O(1) |
| 9 | Implement strStr() | Easy | O(n×m) | O(1) |
| 10 | Search in Rotated Sorted Array | Medium | O(log n) | O(1) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Two Sum | Easy | O(n) | O(n) |
| 2 | Insert Interval | Medium | O(n) | O(n) |
| 3 | Text Justification | Hard | O(n) | O(n) |
| 4 | Minimum Window Substring | Hard | O(n) | O(k) |
| 5 | Maximal Rectangle | Hard | O(m×n) | O(n) |
| 6 | The Skyline Problem | Hard | O(n log n) | O(n) |
| 7 | Maximal Square | Medium | O(m×n) | O(m×n) |
| 8 | Find Median from Data Stream | Hard | O(log n) insert, O(1) find | O(n) |
| 9 | Bulls and Cows | Medium | O(n) | O(1) |
| 10 | Count of Smaller Numbers After Self | Hard | O(n log n) | O(n) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Two Sum | Easy | O(n) | O(n) |
| 2 | Insert Interval | Medium | O(n) | O(n) |
| 3 | Text Justification | Hard | O(n) | O(n) |
| 4 | Minimum Window Substring | Hard | O(n) | O(k) |
| 5 | Maximal Rectangle | Hard | O(m×n) | O(n) |
| 6 | The Skyline Problem | Hard | O(n log n) | O(n) |
| 7 | Maximal Square | Medium | O(m×n) | O(m×n) |
| 8 | Find Median from Data Stream | Hard | O(log n) insert, O(1) find | O(n) |
| 9 | Bulls and Cows | Medium | O(n) | O(1) |
| 10 | Count of Smaller Numbers After Self | Hard | O(n log n) | O(n) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Nested List Weight Sum II | Medium | O(n) | O(n) |
| 2 | Shortest Word Distance II | Medium | O(n) | O(n) |
| 3 | Closest Binary Search Tree Value II | Medium | O(n) | O(n) |
| 4 | Two Sum III - Data structure design | Easy | O(n) | O(n) |
| 5 | Nested List Weight Sum | Medium | O(n) | O(n) |
| 6 | Max Stack | Medium | O(n) | O(n) |
| 7 | Find Leaves of Binary Tree | Medium | O(n) | O(n) |
| 8 | All O'one Data Structure | Hard | O(1) for each operation | O(n) |
| 9 | Can Place Flowers | Easy | O(n) | O(1) |
| 10 | Factor Combinations | Medium | O(2ⁿ) | O(n) |
| 11 | Paint House | Medium | O(n) | O(1) |
| 12 | Paint House II | Hard | O(n×k) | O(n) |
| 13 | Evaluate Reverse Polish Notation | Medium | O(n) | O(n) |
| 14 | Shortest Word Distance | Easy | O(n) | O(1) |
| 15 | Text Justification | Hard | O(n) | O(n) |
| 16 | Count Different Palindromic Subsequences | Hard | O(n²) | O(n²) |
| 17 | Binary Tree Upside Down | Medium | O(n) | O(n) |
| 18 | Max Points on a Line | Hard | O(n²) | O(n) |
| 19 | Partition to K Equal Sum Subsets | Hard | O(n×2^n) | O(n) |
| 20 | Insert Delete GetRandom O(1) | Medium | O(1) for each operation | O(n) |
| 21 | Number of Islands | Medium | O(m×n) | O(m×n) |
| 22 | Exclusive Time of Functions | Medium | O(n) | O(n) |
| 23 | Valid Triangle Number | Medium | O(n²) | O(1) |
| 24 | Valid Number | Medium | O(n) | O(1) |
| 25 | Repeated DNA Sequences | Medium | O(n) | O(n) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | Add Two Numbers | Medium | O(max(m,n)) | O(max(m,n)) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity |
|---|---|---|---|---|
| 1 | LRU Cache | Medium | O(1) for each operation | O(n) |
| 2 | Department Top Three Salaries | Hard | O(n log k) | O(n) |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity | Notes |
|---|---|---|---|---|---|
| 1 | LRU Cache | Medium | O(1) | O(capacity) | System design classic |
| 2 | Time Based Key-Value Store | Medium | O(log n) | O(n) | Practical data structure |
| 3 | Design Search Autocomplete System | Hard | O(p + q log q) | O(n) | Real-world system |
| 4 | Implement Trie (Prefix Tree) | Medium | O(m) | O(ALPHABET_SIZE×N×M) | NLP applications |
| 5 | Word Search II | Hard | O(m×n×4^s) | O(n) | Advanced trie usage |
| 6 | Serialize and Deserialize Binary Tree | Hard | O(n) | O(n) | Data persistence |
| 7 | Design In-Memory File System | Hard | O(m + k log k) | O(n) | Unix cd simulation |
| 8 | LFU Cache | Hard | O(1) | O(capacity) | Advanced caching |
| 9 | Design Twitter | Medium | O(n log n) | O(n) | Social media system |
| 10 | Top K Frequent Elements | Medium | O(n log k) | O(n + k) | ML preprocessing |
| 11 | K Closest Points to Origin | Medium | O(n log k) | O(k) | ML algorithms |
| 12 | Merge k Sorted Lists | Hard | O(n log k) | O(1) | Distributed systems |
| 13 | Course Schedule II | Medium | O(V + E) | O(V + E) | Dependency resolution |
| 14 | Word Ladder | Hard | O(M²×N) | O(M²×N) | NLP transformations |
| 15 | Minimum Window Substring | Hard | O( | s | + |
| 16 | Design Hit Counter | Medium | O(1) amortized | O(1) | Rate limiting |
| 17 | Design Log Storage System | Medium | O(n) | O(n) | System monitoring |
| 18 | Valid Parentheses | Easy | O(n) | O(n) | Code parsing |
| 19 | Longest Increasing Path in a Matrix | Hard | O(m×n) | O(m×n) | DP optimization |
| 20 | Maximum Subarray | Medium | O(n) | O(1) | ML loss functions |
View Problems
| No. | Problem | Difficulty | Time Complexity | Space Complexity | Notes |
|---|---|---|---|---|---|
| 1 | Binary Search | Easy | O(log n) | O(1) | Core algorithm |
| 2 | Search Insert Position | Easy | O(log n) | O(1) | Binary search variant |
| 3 | Find Peak Element | Medium | O(log n) | O(1) | Binary search on unsorted |
| 4 | Search in Rotated Sorted Array | Medium | O(log n) | O(1) | Modified binary search |
| 5 | Find Minimum in Rotated Sorted Array | Medium | O(log n) | O(1) | Rotation point |
| 6 | Search a 2D Matrix | Medium | O(log(m*n)) | O(1) | 2D binary search |
| 7 | Median of Two Sorted Arrays | Hard | O(log(min(m,n))) | O(1) | Advanced binary search |
| 8 | Shortest Path in Binary Matrix | Medium | O(n²) | O(n²) | BFS shortest path |
| 9 | Number of Islands | Medium | O(m×n) | O(m×n) | DFS/BFS |
| 10 | Word Ladder | Hard | O(M²×N) | O(M²×N) | BFS word transformation |
| 11 | Course Schedule | Medium | O(V+E) | O(V+E) | Topological sort |
| 12 | Course Schedule II | Medium | O(V+E) | O(V+E) | Topological ordering |
| 13 | Alien Dictionary | Hard | O(C) | O(1) | Topological sort |
| 14 | Valid IP Addresses | Medium | O(3^4) | O(1) | IP validation |
| 15 | LRU Cache | Medium | O(1) | O(capacity) | Data structure design |
| 16 | Implement Trie (Prefix Tree) | Medium | O(m) | O(26×N×M) | Trie data structure |
| 17 | Design Hit Counter | Medium | O(1) amortized | O(1) | Time series design |
| 18 | Logger Rate Limiter | Easy | O(1) | O(M) | Rate limiting |
| 19 | Print in Order | Easy | O(1) | O(1) | Concurrency |
| 20 | Print FooBar Alternately | Medium | O(n) | O(1) | Concurrency/Threading |
The ultimate collection for technical interview success! This repository provides comprehensive coverage of:
- 400+ Curated Problems across 15+ top tech companies
- NeetCode 150 & Blind 75 - Industry-standard problem sets
- Latest 2025 Questions from FAANG and emerging companies
- System Design interview preparation
- AI/ML Resources for specialized roles
Perfect for FAANG, unicorns, and top tech interviews!
📚 Complete System Design Interview Guide - Top 25 system design problems with complexity ratings and company tags.
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