LeetCode 242: Valid Anagram | Brute Force vs Optimized (JavaScript)

In this video, I solve LeetCode 242: Valid Anagram using two approaches in JavaScript:

1️⃣ A simple brute-force method that sorts both strings and compares them
2️⃣ An optimized solution using a hash map (character frequency counter) for better performance

🔄 Quick Note: I mentioned in the video that sorting runs in O(n) — that was a slip!
The correct time complexity for sorting with .sort() is O(n log n) because it's a comparison-based algorithm.

Thanks to the BST-style decision tree behind the scenes, even modern engines like V8 (Chrome) use Timsort, which is based on merge/insertion sort.

The hash map version, on the other hand, is O(n) and uses only one pass through each string, which makes it faster and more scalable for large inputs.

What You’ll Learn:
✅ Why sorting works for anagrams (but isn't optimal)
✅ How to build a character frequency map using Map()
✅ A common mistake in time complexity (and how to catch it)
✅ Time & space complexity breakdowns

Chapters:
0:00 - Question
0:45 - Brute Force with Sorting Explanation
2:44 - Brute Force Code(Correction: Sorting is O(n log n), not O(n))
3:52 - Optimized Hash Map Logic
7:45 - HashMap Code Walkthrough
10:00 - Complexity Breakdown

💬 Want to see this done with Counting Sort for lowercase-only input? Comment below!

#leetcode #validanagram #javascript #leetcode242 #anagramcheck #hashmap #stringproblems #codinginterview #bigO #timecomplexity

Видео LeetCode 242: Valid Anagram | Brute Force vs Optimized (JavaScript) канала Crappy Coder