🧱 Beginner-Friendly Guide 'Minimum Swaps to Arrange a Binary Grid' - Problem 1536 (C++, Python, JavaScript)

Sorting a grid might seem like a complex task, but it often boils down to identifying a single critical property of each row. In this challenge, we explore how to transform a matrix through greedy swaps to satisfy a specific geometric constraint. You're given: An n \times n binary grid consisting of 0s and 1s. The ability to swap any two adjacent rows. Your goal: Find the minimum number of swaps needed so that all cells above the main diagonal are zeros. Return -1 if it is impossible to reach this state. Intuition: The Power of Suffix Zeros To make a grid "valid," the first row must have at least n - 1 zeros at the end. The second row needs at least n - 2 zeros, and so on. The last row doesn't require any trailing zeros. Instead of moving the whole grid, we can simplify each row into a single number: the count of consecutive zeros starting from the right (suffix zeros). The strategy is Greedy: For the current row i, determine how many suffix zeros are required (n - 1 - i). Search downw