Sudoku Players' Forum (clone)

Stuck right at the end! any ideas?

https://ibb.co/zPKzLPk

Code: Select all

*-------------------------------*
| 1 28 4  | 5  6 23 | 38   7  9 |
| 5 28 7  | 23 9 4  | 1    38 6 |
| 9 3  6  | 7  1 8  | 4    5  2 |
|---------+---------+-----------|
| 2 7  8  | 1  4 9  | 5    6  3 |
| 3 6  9  | 8  2 5  | 7    4  1 |
| 4 1  5  | 6  3 7  | 9    2  8 |
|---------+---------+-----------|
| 6 5  23 | 9  7 1  |*3-28 38 4 |
| 7 9  23 | 4  8 23 | 6    1  5 |
| 8 4  1  | 23 5 6  | 23   9  7 |
*-------------------------------*

Bug+1 => r7c7 = 3. You can read about the BUG principle, for example, here or here.

Leren

Wow, thank you! I half understand the principal lol

Do you think it was a flaw in my solving, in the design of the puzzle or was this supposed to happen?

If the dark black numbers in the diagram are the only clues, there are only 13 of them, and reading the stuff at the bottom tells me that this must be some sort of variant with some extra constraints.

A normal sudoku must have at least 17 clues for a unique solution, so you apparently got to your solved state using the extra constraints.

In this case the final solution was a valid sudoku grid, so for this puzzle, the extra information seems to be consistent with the extra Sudoku clue requirements.

Leren