This popular Japanese number puzzle has just one easy rule: In every Row, every Column and every 3x3 sub-grid, all the numbers from 1 to 9 should appear, but only once in each row, column and sub-grid.
+------+-------+------+
| 0 0 0 | 7 0 0 | 4 0 0 |
| 0 3 0 | 0 9 0 | 0 2 0 |
| 4 0 0 | 0 0 5 | 0 0 0 |
+------+-------+------+
| 0 0 8 | 0 0 0 | 0 0 5 |
| 0 9 0 | 0 3 0 | 0 7 0 |
| 6 0 0 | 0 0 0 | 3 0 0 |
+------+-------+------+
| 0 0 0 | 4 0 0 | 0 0 6 |
| 0 7 0 | 0 2 0 | 0 9 0 |
| 0 0 5 | 0 0 8 | 0 0 0 |
+------+-------+------+

Replace the 0's with the digits required to satisfy the rule.

(In reply to re: Program execution in less than a minute by Ken Haley)

When I put in the OPTION STRICT ON clause, and made variables global, as you suggested for the puzzle "Self-referential Numbers" on 9/24/05, my program for this puzzle runs in exactly 2 seconds.

Thank you so much for that suggestion, Ken !

Posted by Penny on 2005-09-25 02:13:34