jeffsieu / py-sudoku Goto Github PK

__get_solution() function in solve() function can generate an infinite loop when the sudoku is wrong, see example below

+-------+-------+-------+
|       |       |       |
| 7   6 |       |     6 |
|       |       |       |
+-------+-------+-------+
|   7   |   7   |     3 |
| 8     |       |     5 |
| 2 3   |   9   |   7   |
+-------+-------+-------+
|   5   | 7     |       |
| 3     |       | 7     |
|     7 |     9 |       |
+-------+-------+-------+

For a sudoku board to be valid, there should be exactly ONE solution to an unsolved board. That means the difficulty parameter (in float) could tamper the legitimacy of a sudoku problem.

There are quite a lot of solutions for creating sudoku boards with only one solution.

It would be great if solving an unsolvable puzzle would lead to an machine-readable exception. Currently the only thing that happens is that a string is printed out.

Sudoku(4, seed=13).difficulty(0.1)

difficulty can be anything from 0.01 to 0.9
size 3 is working, but for sizes 4 and 5 causing an infinite loop