PlaySudoku.us
Medium · Puzzle #819
4
6
8
5
2
3
9
8
4
6
8
4
6
6
7
9
8
1
3
1
2
7
6
4
8
1
5
9
6
7
1
3
7
5
4
"You have to have the fighting spirit. You have to force moves and take chances." — Bobby Fischer
"You have to have the fighting spirit. You have to force moves and take chances." — Bobby Fischer
Donald Knuth's "Algorithm X" with dancing links solves exact cover problems — of which Sudoku is a special case.
Donald Knuth's "Algorithm X" with dancing links solves exact cover problems — of which Sudoku is a special case.