Leetcode 3197. Find the Minimum Area to Cover All Ones II

Given an m×n (m,n ≤ 30) binary grid, partition all 1-cells into three non-overlapping axis-aligned rectangles of non-zero area (rectangles may touch) whose union covers every 1, and minimize the total sum of their areas. The core challenge is finding the optimal way to group 1s into three disjoint bounding boxes under the non-overlap constraint.