DSA Interview Roadmap

A step-by-step plan to get good at DSA interviews.

---

Rules of the Series

1. Fork & maintain notes. Fork this repo and create *.notes.md files alongside each problem file. For example, maintain array.notes.md with all your notes for problems discussed — use a table format (problem, approach, complexity, key takeaway).

2. Always use the correct approach. Even if a brute-force or suboptimal algorithm passes the test cases, that does not mean you can get away with it in a standard DSA round. Solve every problem with the intended optimal approach.

3. Solve by applying patterns, not ad-hoc. Identify the underlying pattern (two pointers, sliding window, BFS, etc.) before writing code. Learn all canonical solutions — don't just memorize, understand why each pattern applies.

---

Level 1 — LeetCode 75

The essentials. Covers all major topics (arrays, trees, graphs, DP, etc.) in 75 problems. Start here.

Level 2 — Top Interview 150

More problems, harder variants, and a few extra topics like matrix, design, and math. The core interview prep.

Level 3 — Targeted Deep-Dives

Go deeper on the topics that trip people up the most:

• Binary Search
• Dynamic Programming
• Graph Theory

Level 4 — Popular Curated Lists

Additional problem lists from well-known content creators:

• NeetCode Blind 75
• NeetCode 150
• NeetCode 250
• Striver SDE Sheet

Level 5 — LeetCode Pattern 500

500 problems organized by pattern. For building speed and recognition. Do this when you want to go from good to great.