I was getting a little hooked on the Su Doku (sudoku?) puzzles that are proliferating in the press, and I couldn’t resist having a go myself at creating a puzzle, but then I thought about doing an alphabetical version which I’ve called Alphadoku. Here it is – a 25×25 grid, you need to make sure that every row, column and 5×5 square has each letter of the alphabet only once. In this example I’ve missed out the Q. Something had to go and Q is very similar to O – perhaps I should have called this AlphanoQ… but anyway. If this first version works expect to see versions with hidden messages, clever patterns and so on.
It should be quite hard but not impossible. And for the fainter hearted, here is the solution.