I’ve been writing some code (in Java) to solve this fun puzzle. I’ve played the puzzle for many years – it’s part of the excellent and free Simon Tatham’s Portable Puzzle Collection which has been available on many platforms for ages and has recently been ported to Android too. Untangle was inspired by Planarity, written… Continue reading Untangle, Planarity.
Above is a snapshot image. Here’s the real thing. It works for any size of cube from 2 x 2 x 2 up to 11 x 11 x 11. Actually, 11 is an arbitrary limit – the same code would work for any size of cube. Use the little + and – buttons up in the top… Continue reading Flash Rubik Cube Simulator
Place five queens on a chess board so that every square on the board is attacked. It’s an old and famous problem; there are lots of solutions and it’s pretty easy to find one. Try it for yourself and see! Now try using just three queens and two rooks. Not so easy this time; the… Continue reading The Minimum Attack Problem