LeetCode Daily | Max Square ≤ Threshold (1292) | Prefix Sum + Binary Search | C++

In today’s LeetCode Daily Challenge, we solve 1292. Maximum Side Length of a Square with Sum Less Than or Equal to Threshold using an optimized Prefix Sum + Binary Search approach. problem: https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold/description/ solution: https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold/solutions/7508000/this-matrix-problem-looks-hard-until-you-mj23 Instead of checking every possible square naively, we: Precompute a 2D prefix sum to get any submatrix sum in O(1) Apply binary search on the possible square side length Efficiently validate whether a square of size k × k satisfies the threshold This approach is highly interview-relevant and commonly asked in matrix optimization problems. 🔍 What you’ll learn: How to use 2D prefix sums How to combine binary search with matrix problems How to reduce brute force complexity dramatically ⏱ Complexity: Time: O(m × n × log(min(m, n))) Space: O(m × n) 📌 Watch till the end to understand why binary search works here. 🔔 Subscribe to The Boolean Brain for daily LeetCode solutions, interview prep, backend engineering & system design. 📧 Email: [email protected] 📸 Instagram: @thebooleanbrain