The New Sudoku Players' Forum

[m_b_metcalf]

X-sudokus seem to have disapeared from view recently, but when I looked again at my program for this thread, I saw some interesting puzzles being produced during testing:

Code: Select all

 . . . 8 . 3 . . .
 . 3 . . . . . 7 .
 8 . . . . . . . 2
 . . . . 1 . . . .
 . . 5 4 . 6 3 . .
 . . . . 2 . . . .
 1 . . . . . . . 6
 . 9 . . . . . 2 .
 . . . 1 . 9 . . .  18-clue symmetric


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 . . . . . . . . .
 . . . . . . . . .
 4 . 5 3 . 1 9 . 8
 . 9 . 4 . 3 . 1 .
 1 . . . 2 . . . 3
 . 5 . 1 . 8 . 6 .
 3 . 8 9 . 7 6 . 1
 . . . . . . . . .
 . . . . . . . . .  2 x 2 empty rows, symmetric
 

Code: Select all

 . . . . . . . . .
 . . . . . . . . .
 . . . . . . . . .
 . . . . 6 . . . .
 . 1 . 4 . 8 . . 6
 9 . . 3 . . . . .
 . . . . 9 . 5 . .
 . 6 1 . . . . . 3
 . 4 . . . 2 . . 7   empty band, 15 clues


Is anyone still interested in these?

Regards,

Mike Metcalf

[udosuk]

Is anyone still interested in these?

In Ruud's website there're still daily X-file puzzles available.

In the holy land of Killer Sudoku, namely djape's website, about half of the puzzles available are X puzzles... And 80% of the puzzles posted in it's forum are with the X property... In fact it's becoming rarer and rarer to see non-X killer puzzles posted by the forum members there...

The X puzzles do have some attractiveness, and contain more fishy moves than non-X ones... I used to develop a bunch of turbot-fish style techniques and name them "crossover" moves...

I think the current record for fewest givens in an X puzzle is 13, perhaps you'd like to try your program's luck to break that record...

[m_b_metcalf]

I think the current record for fewest givens in an X puzzle is 13, perhaps you'd like to try your program's luck to break that record...

It's here. The problem is speed. It's well known that solvers slow down with fewer than about 20 clues. Working with fewer than 16 is far worse .

Regards,

Mike Metcalf