A new version of the program checker is now available (free) at
http://www.maths.nuim.ie/staff/gmg/sudoku
Source code and windows executable files all available for download.
Checker was written to search exhaustively through a completed grid for a puzzle with n clues. We have added some things.
New Features
- Checker, unavoid work for Sudoku-X and Sudoku-DG also.
- Checker allows you to fix more than just a single clue (to search certain branches of the search tree only), also useful for splitting search jobs over several computers.
- Checker and unavoid now find all unavoidable sets of size up to 12.
- Unavoidable sets are saved to a file.
- Checker doesn't stop when finding one puzzle. Saves puzzles found to a file.
- Checker and unavoid assign themselves lowest thread priority on windows.
- Has a "random" mode: search tuples in random order, which is useful for finding n-puzzles, and also allows you to reliably estimate the computation time for a full search.
- option to search for pseudo-puzzles with 2 solutions as well.
- print statistics (percentage of time spent in solver).
Thanks are due to many people, including Red Ed, Ocean, dukuso, gsf, gfroyle.