LeetCode 3979: Maximum Valid Pair Sum | C++ (Brute Force to Optimal)

LeetCode 3979: Maximum Valid Pair Sum | C++ (Brute Force to Optimal) Welcome back to AeXel Today we are tackling LeetCode 3979: Maximum Valid Pair Sum. In coding rounds, getting the logic to work is only step one—optimizing it is what actually gets you the offer. We will start by breaking down the intuitive O(N²) Brute Force approach, explain why it might hit a Time Limit Exceeded (TLE) error, and then optimize it down to a blazing fast O(N) solution by keeping track of the maximum value on the fly! 📌 What you will learn: Understanding the (j - i ≥ k) distance constraint. The pitfalls of nested loops in array problems. How to optimize using a running maximum variable. Writing clean, interview-ready C++ code.