Fortran generated sudokus

FWIW, this book: * Charnick, Bernard (2023). Sudoku with Symmetry. lulu.com. pp. viii + 220. ISBN 978-1-4475-1761-0. contains puzzles generated by Fortran programs.

Mike

In 2006, I wrote a Fortran program which can generate sudokus and solve them, with random strategies. But it was written in French for a student project. And the code was never modernized.

If someone is interested I could put it online. But I have no time to rework it fully…

 Voici la grille de départ :
 0 4 0 | 0 0 0 | 3 0 8
 0 0 0 | 7 4 0 | 2 0 0
 0 0 9 | 0 1 8 | 0 0 0
 ------+-------+------
 0 7 0 | 0 0 0 | 9 0 0
 8 0 0 | 3 0 5 | 0 6 0
 0 0 0 | 0 8 7 | 0 5 3
 ------+-------+------
 0 0 0 | 0 7 0 | 0 0 4
 0 0 3 | 8 0 0 | 0 0 9
 2 0 0 | 0 0 0 | 0 0 0

 Voici la grille résolue (validité vérifiée) :
 1 4 2 | 5 9 6 | 3 7 8
 5 8 6 | 7 4 3 | 2 9 1
 7 3 9 | 2 1 8 | 6 4 5
 ------+-------+------
 3 7 5 | 1 6 4 | 9 8 2
 8 9 1 | 3 2 5 | 4 6 7
 6 2 4 | 9 8 7 | 1 5 3
 ------+-------+------
 9 1 8 | 6 7 2 | 5 3 4
 4 6 3 | 8 5 1 | 7 2 9
 2 5 7 | 4 3 9 | 8 1 6

In 1996 you wrote an article A Sudoku program in Fortran 95. Could you possibly post the code?

Ah, yes, so long ago. I’d have to work very hard to get it into a publishable form, and I leave home tomorrow for at least four weeks. So, sorry, no.

And vmagnin’s sudoku is, unfortunately, invalid. It has 2 solutions: the 1 and 4 in rows 5 and 6 of the solution grid can be interchanged.

Regards,

Mike