Howard
See these very interesting posts by Calvin
http://blogs.msdn.com/calvin_hsia/search.aspx?q=sudoku&p=1

Jaime

>I guess everyone has heard of Soduko (http://www.soduko.org/)
>
>I thought it would be a great project for me to get my feet wet w/Visual Studio...but...I'm having a terrible time trying to figure out the logic to create the puzzles. Here are the requirements:
>
>1. There's a 9x9 grid
>2. Each column contains the number 1-9 without duplicates
>3. Each row contains the numbers 1-9 without duplicates
>4. Each 3x3 grid contains the numbers 1-9 without duplicates - there are 9 of these 3x3 grids and they do not overlap - it looks something like this:
>
>x x x - x x x - x x x
>x x x - x x x - x x x
>x x x - x x x - x x x
>
>x x x - x x x - x x x
>x x x - x x x - x x x
>x x x - x x x - x x x
>
>x x x - x x x - x x x
>x x x - x x x - x x x
>x x x - x x x - x x x
>
>It sounded rather easy at first - but - I can't get a handle on how to do this - any suggestions would be great. All I'm looking for is the logic - so if you only "speak" VFP, that would be fine...
>
>Thanks!