Transform to Chessboard

Given an n×n binary grid where you may swap any two rows or any two columns, determine whether you can reorder rows/columns to form an alternating "chessboard" pattern and if so return the minimum number of swaps, otherwise return -1. The core challenge is to verify feasibility from the row/column pattern constraints (only two complementary row types and two complementary column types with correct counts) and compute the minimal row-swaps and column-swaps needed to achieve an alternating arrangement.