The Ultimate List of 50+ LeetCode Problems for Technical Interviews

If you’re preparing for a coding interview, you know that practising LeetCode problems is one of the best ways to sharpen your problem-solving skills. But with thousands of problems available, where do you start? Don’t worry — I’ve got you covered! Here’s a hand-picked list of 50+ essential LeetCode problems that will help you ace your next technical interview.

Why Focus on These Problems?

These problems are frequently asked in top tech company interviews (Google, Facebook, Amazon, etc.) and cover key data structures and algorithms. Solving them will make you more confident and improve your ability to tackle real-world challenges.

1. Arrays & Strings (Fundamentals You Must Master)

• Two Sum
• Best Time to Buy and Sell Stock
• Contains Duplicate
• Product of Array Except Self
• Maximum Subarray
• 3Sum
• Container With Most Water

2. Linked Lists (A Must-Know for Interviews!)

• Reverse a Linked List
• Detect Cycle in a Linked List
• Merge Two Sorted Lists
• Remove Nth Node From End of List
• Reorder List

3. Trees & Graphs (Commonly Asked in FAANG Interviews)

• Maximum Depth of Binary Tree
• Same Tree
• Invert/Flip Binary Tree
• Binary Tree Maximum Path Sum
• Validate Binary Search Tree
• Kth Smallest Element in a BST
• Word Search

4. Dynamic Programming (Essential for Advanced Problems)

• Climbing Stairs
• Coin Change
• Longest Increasing Subsequence
• Word Break
• House Robber
• Decode Ways
• Unique Paths
• Jump Game

5. Backtracking (Great for Recursion Practice)

• Subsets
• Combination Sum
• Permutations
• Palindrome Partitioning

6. Sorting & Searching (Optimize Your Code!)

• Merge Intervals
• Top K Frequent Elements
• Find Median from Data Stream

7. Design & System Design (For Experienced Candidates)

• Design HashMap
• Design LRU Cache
• Design Twitter

8. Bonus: Math, Geometry & More!

• Rotate Image
• Spiral Matrix
• Set Matrix Zeroes
• Sudoku Solver

How to Use This List Effectively?

1. Start with Arrays & Strings if you’re a beginner.
2. Move on to Linked Lists and Trees once comfortable.
3. For advanced prep, dive into Graphs, Dynamic Programming & Backtracking.
4. Practice at least 2–3 problems per day to build consistency.
5. Always read and understand multiple solutions (Brute force → Optimized approach).
6. Mock interviews are a great way to simulate real conditions!

Conclusion

Mastering these 50+ problems will give you a solid foundation for acing your coding interview. Remember, consistency is key! Keep practising, stay patient, and trust the process. 🚀

Happy coding! 😃