Find the Length of the Longest Common Prefix | LeetCode 3043 | HashSet | Trie

In this video, we solve LeetCode 3043: Find the Length of the Longest Common Prefix, a very interesting problem that builds strong intuition around strings, prefixes, hashing, and efficient comparison techniques.

At first, it may look like a basic comparison problem — but the challenge is finding the maximum common prefix efficiently across two arrays.

💡 Core Idea:

For every number in both arrays:

✔ Generate prefixes from left to right
✔ Compare prefixes efficiently
✔ Find the maximum matching prefix length

The goal is to maximize the prefix length among all possible pairs.

🚀 What’s covered in this video:

✅ Problem statement with examples
✅ Understanding numeric prefixes clearly
✅ Brute force intuition
✅ Optimized hashing/set approach
✅ Step-by-step dry run
✅ Prefix generation logic
✅ Clean and efficient code walkthrough

🧠 Key Insight:

A prefix always starts from the leftmost digit.

Example:

👉 123 is a prefix of 12345
👉 12 is also a prefix
👉 234 is NOT a prefix

We efficiently store prefixes from one array and compare them with the second array to get the longest match.

🎯 Why this problem is important:

Builds strong prefix matching intuition
Great practice for hashing and string manipulation
Helps improve observation and optimization skills
Common interview-style pattern recognition problem
Excellent for beginners and intermediate DSA learners

🔥 What you’ll learn:

Prefix generation techniques
Efficient comparison strategies
Using hashing for optimization
String and number manipulation
Writing clean and optimized solutions

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#Leetcode #DSA #Algorithms #CodingInterview #ProblemSolving #Hashing #Strings #Prefix #Java #Coding

Видео Find the Length of the Longest Common Prefix | LeetCode 3043 | HashSet | Trie канала Streak To Scale