4
3
7
8
8
9
3
6
2
1
8
7
7
9
9
1
4
6
7
5
3
5
6
4
1
7
7
8
6
9
3
1
9
3
8
1
5
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.
"To know what you know and what you do not know — that is true knowledge." — Confucius
"To know what you know and what you do not know — that is true knowledge." — Confucius