Sudoku is a popular puzzle game. This directory contains a fast Sudoku solver that translates the puzzle into an exact set cover problem.
The input to the solver is an 81-character string that contains the contents of the board you'd like to solve in row-major order with a '.' in the place of each unknown cell. The output is the same but with no unknown cells.
For example, the following puzzle:
Is encoded as "53..7....6..195....98....6.8...6...34..8.3..17...2...6.6....28....419..5....8..79".
You can pass this to the solver by running:
$./solve-sudoku.sh "53..7....6..195....98....6.8...6...34..8.3..17...2...6.6....28....419..5....8..79"
Which should print the solution
534678912672195348198342567859761423426853791713924856961537284287419635345286179
The script solve-all-hard-sudokus.sh exercises the solver by downloading the list of hard
puzzles at http://magictour.free.fr/top95 and solving them all.