PlaySudoku.us
Evil · Puzzle #527
6
1
7
4
1
8
5
7
7
6
8
4
9
6
2
8
3
8
1
2
2
6
9
8
5
Techniques used
- Naked Single
- Hidden Single
- Naked Pair
- Pointing Pair
- Box-Line Reduction
- Skyscraper
- W-Wing
- X-Wing
- XY-Wing
There are Sudoku variants with extra constraints: Killer Sudoku (cage sums), Diagonal Sudoku, and even 3D Sudoku.
There are Sudoku variants with extra constraints: Killer Sudoku (cage sums), Diagonal Sudoku, and even 3D Sudoku.
A Sudoku grid can be solved using only row and column logic, never needing box constraints — but it becomes exponentially harder.
A Sudoku grid can be solved using only row and column logic, never needing box constraints — but it becomes exponentially harder.