http://www.idontplaydarts.com/code/sudoku-solver/

Nice solver – I’ve written a few of these for fun too.  You may wish to look into prolog solvers, which are absurdly cool because you define how sudoku works and the puzzle instance and it manages to do it with a screenful of code and bloody quickly to boot.

~Ed  (a.k.a. shimmer – *shudder*)

 Now I’ve done that I can see the limitations of it, and I’m thinking of ways to improve it. The system you’ve used is good as the start of a better solution.

 The Sudoku page on Wikipedia has a small section on computer solutions which is quite interesting.

 I intend to add a system whereby the script can keep track of the possibilities of all of the boxes, much like a person might do by writing little numbers in the corners of the boxes.

@ Eddie: I’ve used Prolog a little bit for my A2 Level Computing course. I found it difficult to get used to after only using procedural languages before. The most complex thing I managed to code was a family tree where you could ask what relation someone was to someone else. It’s a powerful language though for sure. And I agree; very cool

http://www.norvig.com/sudoku.html