The New Sudoku Players' Forum

[psychopixel]

Hi everyone,

Code: Select all

 
 +-----------------------+
 | A B C | A B C | A B C |
 | D E F | D E F | D E F |
 | G H I | G H I | G H I |
 |-------+-------+-------|
 | A B C | A B C | A B C |
 | D E F | D E F | D E F |
 | G H I | G H I | G H I |
 |-------+-------+-------|
 | A B C | A B C | A B C |
 | D E F | D E F | D E F |
 | G H I | G H I | G H I |
 +-----------------------+


Imagine a sudoku like this where also positions with same letters must have different number.
It's possible to have a sudoku like this?
There's a name for this kind of sudoku?
If it is possible who can send me a similar sudoku?
thanks

[coloin]

Sudoku DG I think.....

11 clues from Ruud

Code: Select all

. 4 6|. . .|. . 3
. . .|. . 1|. . .
. . 3|. . .|. . .
-----+-----+-----
2 . .|. . .|. . .
. . .|5 4 .|. . .
8 . .|. . .|7 . .
-----+-----+-----
1 . .|. . .|. . .
. . .|. . .|. . .
. . .|. . .|. . .

046000003000001000003000000200000000000540000800000700100000000000000000000000000


. 4 6|. . .|. . 3
. . .|. . 1|. . .
. . 3|. . .|. . .
-----+-----+-----
2 . .|. . .|8 . .
. . .|9 4 .|. . .
. . .|. . .|7 . .
-----+-----+-----
1 . .|. . .|. . .
. . .|. . .|. . .
. . .|. . .|. . .

046000003000001000003000000200000800000940000000000700100000000000000000000000000


[hobiwan]

My local newspaper publishes two of those (color coded) every sunday. Here are todays puzzles:

Code: Select all

7.2.1...8..97...4.438...7...8.4.5...2...6...1...1.2.8...6...153.7...38..8...2.9.7

7 . 2|. 1 .|. . 8
. . 9|7 . .|. 4 .
4 3 8|. . .|7 . .
-----+-----+-----
. 8 .|4 . 5|. . .
2 . .|. 6 .|. . 1
. . .|1 . 2|. 8 .
-----+-----+-----
. . 6|. . .|1 5 3
. 7 .|. . 3|8 . .
8 . .|. 2 .|9 . 7

.3.......5.18..3...9...7.5..6....4.............3....1..2.5...8...4..97.5.......4.

. 3 .|. . .|. . .
5 . 1|8 . .|3 . .
. 9 .|. . 7|. 5 .
-----+-----+-----
. 6 .|. . .|4 . .
. . .|. . .|. . .
. . 3|. . .|. 1 .
-----+-----+-----
. 2 .|5 . .|. 8 .
. . 4|. . 9|7 . 5
. . .|. . .|. 4 .

[Glyn]

psychopixel coloin is correct that these are DG (Disjoint Group) Sudoku.

The ones posted by Hobiwan are relatively easy as expected from a newspaper, the minimal clues ones given by coloin are Ruudiculously difficult requiring at least a couple of forcing moves.

If you want more puzzles of this type then try Ruud's Sudocue (Windows only) or Jean-Christophe's JSudoku (most platforms with Java) which can both generate, solve and assist with this type of puzzle as well. They apply specialized moves beyond vanilla Sudoku.

[tarek]

These DG puzzles can also be found mixed with other variants....

Here is a minimal 14 clue solvable (No chains needed ) combination of Disjoint Groups & Sudoku X.

Code: Select all

DGX 001
.....19.....3........8.....8.....6............42.....9.....3..5.....6.....64.....
 . . . | . . 1 | 9 . . 
 . . . | 3 . . | . . . 
 . . . | 8 . . | . . . 
-------+-------+------
 8 . . | . . . | 6 . . 
 . . . | . . . | . . . 
 . 4 2 | . . . | . . 9 
-------+-------+------
 . . . | . . 3 | . . 5 
 . . . | . . 6 | . . . 
 . . 6 | 4 . . | . . . 

tarek

[Glyn]

Here is an old thread on this forum from 2005 concerning Magic Sudoku which are quite distinct from DG.

[udosuk]

The ones posted by Hobiwan are relatively easy as expected from a newspaper, the minimal clues ones given by coloin are Ruudiculously difficult requiring at least a couple of forcing moves.

Glyn, since you have a good sense of what should be a reasonable difficulty for a newspaper puzzle, would love to hear your take on this puzzle I posted about. I consider myself a competent player of this genre (No-Operator KenKen) and can't find a simple enough solving path for that puzzle. But on the other hand that has been posted since March 22 and nobody has commented on its difficulty (in here or on the Times pages), so perhaps everybody else has found the easy way to tame this beast which somehow eluded me? Very puzzled.