The New Sudoku Players' Forum

[ixsetf]

It is possible to generate a sudoku puzzle with three empty boxes when the boxes are arranged in a diagonal. However there are no examples of puzzles with three empty boxes in the list of 17s. This raises the question, what is the minimum number of possible clues?

[blue]

Here's one with 18 clues.

Code: Select all

. . . . 4 9 . . .
. . . . . 3 4 . .
. . . . . . 1 8 .
. . . . . . . 5 9
3 . . . . . . . 8
2 4 . . . . . . .
. 5 9 . . . . . .
. . 8 6 . . . . .
. . . 1 3 . . . .

[Serg]

Hi, blue!

Here's one with 18 clues.

Code: Select all

. . . . 4 9 . . .
. . . . . 3 4 . .
. . . . . . 1 8 .
. . . . . . . 5 9
3 . . . . . . . 8
2 4 . . . . . . .
. 5 9 . . . . . .
. . 8 6 . . . . .
. . . 1 3 . . . .

Nice puzzle! This is double-diagonal symmetric 18-clue puzzle (did you search through its full list posted by Afmob?).

Here is my example of 24-clue puzzle, having 3 empty diagonally placed boxes.

Code: Select all

1 9 5 7 8 . . . .
2 . . 4 . . . . .
4 . 7 . . . . . .
6 1 . . . . . . .
8 . . . . . . . 7
. . . . . . . 4 8
. . . . . . 2 . 5
. . . . . 9 . . 1
. . . . 1 3 8 9 6

[JPF]

Yes,
good old days!

a new one :

Code: Select all

 6 9 5 1 . . . . .
 2 . . 7 . . . . .
 1 . . 2 . . . . .
 9 2 8 . . . . . .
 . . . . . . . . .
 . . . . . . 7 3 9
 . . . . . 5 . . 4
 . . . . . 8 . . 3
 . . . . . 9 1 2 6

JPF

[blue]

Nice shapes, Serg and JPF !

This is double-diagonal symmetric 18-clue puzzle (did you search through its full list posted by Afmob?).

No, generated it on the fly. I remembered the shape, but not from where.

Here's another one with 18 clues.

Code: Select all

. . . . . . . . .
. . . . . . 4 6 1
. . . 2 8 3 . . .
1 6 2 . . . . . .
. . . . . . . . .
. . . . . . 3 9 7
. . . 6 1 7 . . .
5 4 3 . . . . . .
. . . . . . . . .