An adversary places eight white rooks and eight black rooks on sixteen squares of a chessboard, subject to these rules:
- In any row, there must be exactly two rooks, one of each color.
- In any column, there must be exactly two rooks, one of each color.
Your goal is then to apply a number of moves in order to achieve the same configuration, but with the colors reversed. Every valid move consists of switching two rows, or switching two columns.
Can you always succeed, no matter how the adversary places the pieces?
Click on the pictures to be taken to an online editor where you can play with the rooks.
A possible initial condition:
The result of switching rows 2 and 4:
The result of switching columns d and g:
The goal posiiton: