PlaySudoku.us
Hard · Puzzle #999
5
4
8
7
5
1
2
8
7
1
3
1
2
8
4
8
6
1
9
4
2
9
3
3
6
1
5
8
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
In combinatorics, the pattern formed by Sudoku clue cells is studied as a problem in 'hitting sets' and transversals.
In combinatorics, the pattern formed by Sudoku clue cells is studied as a problem in 'hitting sets' and transversals.