Sudoku is "a denial of service attack on human intellect". A puzzle is solved if the squares in each unit are filled with a permutation of the digits 1 to 9.
A1 A2 A3| A4 A5 A6| A7 A8 A9 4 . . |. . . |8 . 5 4 1 7 |3 6 9 |8 2 5
B1 B2 B3| B4 B5 B6| B7 B8 B9 . 3 . |. . . |. . . 6 3 2 |1 5 8 |9 4 7
C1 C2 C3| C4 C5 C6| C7 C8 C9 . . . |7 . . |. . . 9 5 8 |7 2 4 |3 1 6
---------+---------+--------- ------+------+------ ------+------+------
D1 D2 D3| D4 D5 D6| D7 D8 D9 . 2 . |. . . |. 6 . 8 2 5 |4 3 7 |1 6 9
E1 E2 E3| E4 E5 E6| E7 E8 E9 . . . |. 8 . |4 . . 7 9 1 |5 8 6 |4 3 2
F1 F2 F3| F4 F5 F6| F7 F8 F9 . . . |. 1 . |. . . 3 4 6 |9 1 2 |7 5 8
---------+---------+--------- ------+------+------ ------+------+------
G1 G2 G3| G4 G5 G6| G7 G8 G9 . . . |6 . 3 |. 7 . 2 8 9 |6 4 3 |5 7 1
H1 H2 H3| H4 H5 H6| H7 H8 H9 5 . . |2 . . |. . . 5 7 3 |2 9 1 |6 8 4
I1 I2 I3| I4 I5 I6| I7 I8 I9 1 . 4 |. . . |. . . 1 6 4 |8 7 5 |2 9 3
- row - r
- column - c
- square - s
- digit - d
- unit - u, ['A1','B1','C1','D1','E1','F1','G1','H1','I1']
- grid - grid, 81 non-blank chars, starting with '.18...7...
- values - dict of possible values, {'A1':'12349', 'A2':'8', ...}
Easy dataset : dataset1.txt
Normal dataset : dataset2.txt
Hard dataset : dataset3.txt (Arto Inkala's puzzle)