Leetcode 1183. Maximum Number of Ones

Given a binary matrix and a set of allowed operations or placement constraints (e.g., flipping rows/columns, selecting submatrices, or placing up to k ones), choose actions to maximize the total number of 1s. The core challenge is a combinatorial optimization over exponential choices that typically calls for bitmask DP, meet‑in‑the‑middle, greedy selection, or flow/graph modeling to prune the search.