They offered to solve just such a puzzle on matrices.
A square matrix N * N is proposed, where N is an odd number. It is required to "move" clockwise the "insides" of 4 triangles formed when the matrix is divided by the square diagonals.
I can not understand how to approach the problem, what algorithm to follow.
(x,y)->(y,-x)->(-x,-y)->(-y,x)->(x,y). - AlexGlebe