rust-sudoku-solver/puzzles/challenge.csv

1	0	0	9	6	2	0	0	0	4
2	0	6	0	0	0	0	0	5	0
3	0	3	0	0	5	8	6	0	0
4	0	0	0	4	0	0	0	0	0
5	0	0	0	0	0	0	3	2	0
6	0	0	7	0	0	3	0	0	0
7	0	7	6	0	0	4	0	9	0
8	0	9	0	0	3	0	0	7	0
9	0	8	0	0	9	0	5	0	2