MS Windows program „Sudoku 1.1”



Kriss Jaxa
Visby, Sweden
Contact: JaxaSoft...


Program description:

This Sudoku (9x9) editor & solver requires MS Windows, XP or better.

„SudSetup.exe” is a setup program, you need to be administrator to be able to install Sudoku program. Help is included in the program.

New logic techniques has added in version 1.1. Difficulty score is little changed.

Sudoku: screen dump Screenshot of hardest Sudoku I know.

Installation / Removing:

Installation: If you have an older Sudoku program – uninstall it with Windows Install/Uninstall facility. Then download & start setup program SudSetup.exe (size: 271495 byte, MD5 checksum: 93e8534e6adfaaf89ca23d7dbbf71e01.

After downloading the file, (if you're afraid that file could be tempered) check it's size, you can check file's digital „fingerprint” - MD5 check sum, e.g. on line http://sha1md5checksum.bugaco.com/cryptocalc/index.html, your checksum must be identical with the value above.

Removing: Use standard Windows uninstall facility.

Terms of the use:

The program is free, no registration is required. When distributing the program it is necessary to note that the program is owned (copyrighted) by JaxaSoft.
You can donate money if you like this program.


Sudoku samples, hardest Sudoku in the World?

The program tries to solve the current sudoku puzzle and when there is a solution a difficult score (Difficulty) is shown.

The Difficulty is of course somewhat arbitrary. The solving may consist of two stages:

  1. logical elimination, much like we humans do
  2. systematic trying of possible values

If the puzzle can be solved by (1), it gets some score between 2 - ca. 900, depending on the number of loops and which „tricks” was used. „Guess level” is 0.

If after (1) there are still some undetermined fields, the program tries all possible values in first such field and use (1), if only one solutions is found, guess level is 1, difficulty is increased with value 500 * guess_level on each try.

If with fixed value on first multi value field there are still other multi value fields, the whole procedure is repeated recursively.

On the http://staffhome.ecm.uwa.edu.au/~00013890/sudokumin.php site one has published 49151 unique minimal (17 given fields) sudoku, I've solved all and one with highest difficulty is sudoku above, therefore hardest sudoku in the World.


Zipped sudoku files:

namedifficultyguess levelnumber of puzzles
g0.zip5 - 8990471
g1.zip 1,018 - 3,827 176
g2.zip 3,266 - 28,065 2184
g3.zip 6,607 - 239,155 3781
g4.zip 10,466 - 273,217 4417
g5.zip 15,662 - 539,403 5225
g6.zip 22,7431 - 1,435,579 691
g7.zip 33,221 - 687,788 765
g8.zip 56,593 - 938,042 827
gx.zip 286,416 - 5,575,461 9 - 1330