Am 12.10.2005 um 17:31 schrieb Tom Phoenix:
> That's right. Each row, column, and marked region contains each digit
> just once, and there's a unique solution. Enjoy!

After adding arbitrary regions to the solver I get

1    3    5    2    8    9    4    7    6
5    8    2    6    1    7    3    4    9
3    4    7    9    6    5    8    2    1
8    5    3    4    9    1    2    6    7
9    6    4    1    7    2    5    8    3
2    1    6    5    3    4    7    9    8
6    7    9    3    2    8    1    5    4
7    2    1    8    4    6    9    3    5
4    9    8    7    5    3    6    1    2

Runtime is about 750 ms.
http://sts.tuwien.ac.at/go/Squeak/Sudoku.st has been updated.

Kind regards
Georg