Talk:Cut a rectangle: Difference between revisions

But 60 is the number of ways of dividing the rectangle in half -- with one corner guaranteed to always be classified the same way, and also with a guarantee that all true cells classified that way are [transitively] contiguous with each other -- and I only want the options which are symmetric. To test symmetry, I rotate the bit matrix on each axis and then apply logical not to that result -- if that gives me my starting bit matrix, it's a solution that I want.