Phone Keypad Problem Using Recursion | Letter Combinations | LeetCode 17 | DSA in Java Course #22

Learn how to solve the Phone Keypad Problem using Recursion in Java. This video explains letter combinations logic with recursion, dry run, and interview-focused explanation.

Phone Keypad Problem Using Recursion | Letter Combinations | LeetCode 17 | DSA in Java Full Course | Lecture 22

This is the SIXTH video of the Recursion & Backtracking series and Lecture 22 of the DSA in Java Full Course.

In this lecture, you will learn how digits on a phone keypad generate letter combinations using recursion, one of the most important backtracking problems asked in interviews.

📌 Video 6 : Phone Keypad Problem (LeetCode 17)

✅ Topics Covered in this Lecture:
1️⃣ Understanding Phone Keypad Mapping
2️⃣ Recursive approach for Letter Combinations
3️⃣ Dry Run & Recursion Tree
4️⃣ Time & Space Complexity
5️⃣ LeetCode 17 – Java Implementation

Question Link :- https://leetcode.com/problems/letter-...

💡 This video will help you:
✔ Understand recursion + backtracking clearly
✔ Master combination generation problems
✔ Prepare for FAANG & placement interviews
✔ Build a strong base for permutations & combinations

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TIMESTAMPS
00:00:00 | Intro
00:01:43 | Ques - Letter Combinations
00:03:06 | Approach
00:13:40 | Let's write code
00:25:00 | Dry Run
00:34:45 | Time & Space Complexity...?
00:37:46 | Outro

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