The New Sudoku Players' Forum

[Bigtone53]

Congratulations to Thomas Snyder, a regular contributor to this Forum, for winning the 2007 World Sudoku Championship in Prague, having been runner-up last year.

[coloin]

Yes Well done
I think he deserved to win it last year
He can sleep better now Im sure

C

[motris]

Thanks for your kind words. My WSC trip report is now online at my blog if people want to know how it feels going through the championships. I also have two examples of a latin square puzzle, "tablecloth sudoku," that a teammate and I wrote while competing. More relevant for this forum is to post the playoff puzzle that determined the finals which was the diagonal sudoku that follows. Each of the playoff rounds had 2 puzzles and while the "final" puzzle was in the London Times, this tricky diagonal separated first from second place overall.

[wapati]

The final puzzle linked here:

http://wpc.puzzles.com/sudoku/jigsawFinals.htm

must be wrong.

First of all the puzzle is not unique without the extra information.

Worse, it is nor unique AFTER the extra information.


What was the real last puzzle?

[Bigtone53]

First of all the puzzle is not unique without the extra information.

Worse, it is nor unique AFTER the extra information.

I too thought that it did not have a unique solution, with interchangeable 3s, 6s and 9s. However, I had overlooked the condition that each jigsaw-shaped bit contains 1-9 and that sorted out the unique answer.

[Pat]

The final puzzle linked here:

http://wpc.puzzles.com/sudoku/jigsawFinals.htm

must be wrong.

First of all the puzzle is not unique without the extra information.

Worse, it is nor unique AFTER the extra information.


What was the real last puzzle?

this jigsaw-SuDoku
( also at http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/games_and_puzzles/sudoku/article1599976.ece )
does have a single answer

[udosuk]

Thomas, finally solved both your tablecloth puzzles, tough challenges they are! Especially the 2nd one, spent ages mucking around with the candidates before a couple critical moves with the digit least useful at the start revealed some naked pairs... If you guys can solve these puzzles on pen & paper in several minutes then I know how far away I'm from your level...

Solution for puzzle 1 (UP)

Solution for puzzle 2

wapati, I found that the "jigsaw" puzzle does have a unique solution, even without the "extra information"! If you have doubts, post here or PM me 2 or more solutions you worked out, I'll tell you which one is correct.

And the X puzzle is also pretty tough if you do it on pen & paper... Here I'll post the text versions of the X puzzle and the jigsaw puzzle:

Code: Select all

WSC 2007 X puzzle
..2.1.7..
...7.8...
3.......1
.9.....6.
1.......5
.8.....4.
9.......8
...6.7...
..7.2.9..

WSC 2007 jigsaw puzzle
.5..2..3.
2....17.8
4.76.....
.....5...
52.....47
...7.....
.....35.4
3.65....1
.9..7..6.

[wapati]

The final puzzle linked here:

http://wpc.puzzles.com/sudoku/jigsawFinals.htm

must be wrong.

First of all the puzzle is not unique without the extra information.

Worse, it is nor unique AFTER the extra information.


What was the real last puzzle?

this jigsaw-SuDoku
( also at http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/games_and_puzzles/sudoku/article1599976.ece )
does have a single answer

Yep, the added info does make it unique. Thanks!

[udosuk]

Yep, the added info does make it unique. Thanks!

Then again, without the added info it's still unique... But I think you don't care anymore...