Leetcode 2031. Count Subarrays With More Ones Than Zeros

Given a binary array, count subarrays where the number of 1s exceeds the number of 0s by mapping 1→1 and 0→-1 so the problem becomes counting subarrays with positive sum. This reduces to counting pairs of prefix sums where an earlier prefix is smaller than a later one, typically solved in O(n log n) using order-statistics or divide-and-conquer techniques.