rust-sudoku-solver/puzzles/challenge2.csv

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