Karl von Laudermann wrote: > Heh. I already wrote a Sudoku solver back in May; all I have to do > is change the input/output format a bit to match the quiz > example. In the meantime, here's a harder puzzle to test your > programs with: Why is it harder? If an algorithm works, all solvable puzzles are the same? There's a soln on RubyForge somewhere I saw the other day... -- Chris Game This time it will surely run.