LeetCode 39 🔁 Combination Sum | Recursion + Backtracking Step‑by‑Step (Amazon, Google, Meta)

LeetCode 39 🔁 Combination Sum | Recursion + Backtracking Step‑by‑Step (Amazon, Google, Meta)

Master LeetCode 39 – Combination Sum with clear recursion + backtracking strategies that empower you to solve **any** recursive problem in FAANG or tech interviews.

🚀 Frequently asked at:
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- Bloomberg
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🔍 **In this video, you'll learn:**
1️⃣ Building the recursion template: base case, choice, and backtracking
2️⃣ How to avoid duplicates with index tracking
3️⃣ In-place pruning by sorting and limiting choices
4️⃣ Live code walkthrough in C++/Python
5️⃣ Time & space complexity analysis
6️⃣ Why this sets the stage for solving any recursion-related question

💡 **Why it matters:**
This problem isn’t just about summing combinations — it teaches you how to architect recursive solutions from scratch. This pattern translates directly to harder problems like **Word Search**, **Sudoku**, **N-Queens**, and **Graph DFS** — all commonly seen in FAANG rounds.

👍 Like, 🔔 Subscribe & comment with your toughest recursion test case — I’ll tackle it next!
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Видео LeetCode 39 🔁 Combination Sum | Recursion + Backtracking Step‑by‑Step (Amazon, Google, Meta) канала Pen And Paper