PlaySudoku.us
Evil · Puzzle #649
9
4
6
4
3
5
2
7
7
5
2
6
4
9
1
9
2
1
4
7
5
9
8
6
1
Solving Sudoku is NP-complete for an n×n grid. For the standard 9×9, it's fast — but larger grids become exponentially harder.
Solving Sudoku is NP-complete for an n×n grid. For the standard 9×9, it's fast — but larger grids become exponentially harder.
There are Sudoku World Championships held annually, with competitors from over 30 countries.
There are Sudoku World Championships held annually, with competitors from over 30 countries.