Sudoku Players' Forum (clone)

[Rapidsnow]

Just started playing this game, its really fun, but I can't solve the harder puzzles at all (Evil level on web sudoku.) I don't understand these xy wing/matrix/forcing chain things that everyone is talking about. Can anyone explain some of the simpler techniques that aren't completely basic?

[Rapidsnow]

Code: Select all

+------+------+------+
|. 7 1 |. . 4 |. . 6 |
|. . . |. . 3 |. . . |
|. . 3 |. 7 . |2 . 9 |
+------+------+------+
|. 5 2 |. . 9 |. . . |
|. . . |. 8 . |. . . |
|. . . |2 . . |3 4 . |
+------+------+------+
|7 . 8 |. 5 . |9 . . |
|. . . |. . . |. . . |
|5 3 . |9 . . |7 6 . |
+------+------+------+


Thats one I've been trying for a while

[Ruud]

The most popular explanations can be found here:

http://www.angusj.com/sudoku/hints.php

and here:

http://www.simes.clara.co.uk/programs/sudokutechniques.htm

About your posted puzzle, don't waste any time on it. It has 114 solutions. No good as practice material....

Ruud.

[Darth Tater]

Long time reader, and little known poster...how do you know the exact number of solutions?

I'm gonna guess that there is a program or programs out there that can give the exact number of solutions...link please...thanks.

I am still very much a novice though I can solve the hard and have occasionally knocked out an evil on websudoku.com.

Thanks,

DT

[Ruud]

I'm gonna guess that there is a program or programs out there that can give the exact number of solutions...link please...thanks

The program I use can be downloaded from my website here.

Paste the puzzle from the forum into the program and press F9 to solve it. The program should tell you how many solutions there are. For a non-unique puzzle, disable uniqueness test in the options panel first.

Ruud.

[QBasicMac]

I'm gonna guess that there is a program or programs out there that can give the exact number of solutions...link please

Many is right. And, if you are a programmer, you can fairly easily write your own. Here is one in QBasic:
http://www.network54.com/Forum/178387/message/1132625620/

Mac

[Darth Tater]

Ruud and QBasicMac thanks!