Letter Combinations of a Phone Number | LeetCode 17 | Backtracking in C++ | Live DSA

🚀 *Letter Combinations of a Phone Number | LeetCode 17 | Backtracking in C++* Welcome to **Algo Aura**! 👋 In this live DSA problem-solving session, I solve *Letter Combinations of a Phone Number* using **Backtracking in C++**. The problem is based on the mapping of digits from `2` to `9` to letters on a phone keypad. For every digit, we need to explore all possible letter choices and generate every valid combination. 🔹 Approach The solution uses the classic **Backtracking pattern**: *Choose → Recurse → Backtrack* For each digit: • Get its mapped letters • Try each possible letter • Move to the next digit using recursion • Store the combination when all digits are processed 🔹 Example Input: `digits = "23"` Possible combinations include: `ad, ae, af, bd, be, bf, cd, ce, cf` 🔹 Complexity ⏱️ Time Complexity: *O(4^n × n)* 💾 Space Complexity: *O(n)* excluding the space required to store the output. 🎯 What You'll Learn • How to identify backtracking problems • How to generate combinations using recursion • Phone keypad letter mapping • Choose → Recurse → Backtrack pattern • Recursive problem-solving in C++ • How to approach LeetCode DSA problems 💻 *Language:* C++ 📌 *Topic:* Recursion + Backtracking 🧩 *Problem:* Letter Combinations of a Phone Number 🔢 *LeetCode:* 17 If you found the session useful, *Like 👍, Subscribe 🔔, and follow Algo Aura* for more DSA and problem-solving videos. #DSA #LeetCode #Backtracking #Recursion #CPlusPlus #DataStructures #Programming #Coding #AlgoAura #LeetCodeSolutions #CodingInterview