Maximum Cells

Problem Overview

• Select at most two narrow rectangles (1-cell wide column or 1-cell high row) of '.' cells to maximize total cultivated cells.
• Input: array A of N strings forming an N×M grid with '.' (land) and '#' (building); Output: integer max cells.
• Constraints: 1 ≤ N,M ≤ 500; all rows have the same length.
• Real-world context: plan rice cultivation areas on a village map while avoiding buildings.
• From Microsoft interviews; a classic coding interview interview question problem.