Matchsticks to Square | Backtracking + Pruning | JavaScript | LeetCode 473

📝 Description: 🔥 Day 96 of my LeetCode Daily Challenge! In this problem, I solve LeetCode 473 - Matchsticks to Square using Backtracking with pruning in JavaScript. This is a classic recursion + backtracking problem where we need to determine if we can form a square using all given matchsticks. 🧠 Key Idea: A square has 4 equal sides So, total sum of matchsticks must be divisible by 4 We try to assign each matchstick to one of the 4 sides such that: Each side’s length becomes exactly totalSum / 4 ⚡ Approach: Calculate total sum If not divisible by 4 → return false Sort matchsticks in descending order (important optimization 🚀) Use backtracking: Try placing each matchstick on any of the 4 sides Only proceed if it doesn’t exceed target length Backtrack if it doesn’t lead to solution 🚀 Why sorting helps: Placing larger matchsticks first helps fail early, reducing unnecessary recursion. ✅ Complexity: Time Complexity: O(4ⁿ) (backtracking worst case) O(n log n) for sorting Space Complexity: O(n) (recursion stack) 📚 In this video, you will learn: How to solve partition problems using backtracking How to divide elements into equal subsets How pruning improves performance Why sorting helps in recursion problems A common pattern for subset / partition problems 🔗 Problem Link: https://leetcode.com/problems/matchsticks-to-square/ If you found this helpful, don’t forget to like, comment, and subscribe for more daily LeetCode solutions, JavaScript DSA problems, and coding interview prep 🚀 #leetcode #javascript #dsa #day96 #MatchsticksToSquare #LeetCode473 #backtracking #recursion #dfs #codinginterview #algorithms #datastructures #problemsolving #leetcodejavascript #100daysofcode