A simple sudoku solver written in Rust.
$ cargo run --quiet <<END
> 1 0 0 4 0 0 7 0 9
> 0 5 0 7 8 0 0 2 0
> 7 0 9 0 2 3 0 0 6
> 3 0 0 6 0 0 0 0 0
> 6 4 0 0 7 0 0 1 2
> 9 0 8 0 0 2 0 4 5
> 2 3 0 5 0 4 8 0 0
> 0 6 0 0 9 0 0 3 0
> 8 0 7 0 0 1 0 6 4
> END
1 2 3 4 5 6 7 8 9
4 5 6 7 8 9 1 2 3
7 8 9 1 2 3 4 5 6
3 1 2 6 4 5 9 7 8
6 4 5 9 7 8 3 1 2
9 7 8 3 1 2 6 4 5
2 3 1 5 6 4 8 9 7
5 6 4 8 9 7 2 3 1
8 9 7 2 3 1 5 6 4