## So much for the Uniqueness idea!

Post the puzzle or solving technique that's causing you trouble and someone will help

### So much for the Uniqueness idea!

Saturday, Dec 3

Two solutions?

Mac
QBasicMac

Posts: 441
Joined: 13 July 2005

Code: Select all
`+-------+-------+-------+| . . . | 9 6 . | . . 8 | | 9 . 6 | . . . | . 7 5 | | . . . | . 2 . | . 3 . | +-------+-------+-------+| . 8 . | . 7 1 | . . 4 | | . . . | . . . | . . . | | 3 . . | 8 4 . | . 1 . | +-------+-------+-------+| . 3 . | . 8 . | . . . | | 4 2 . | . . . | 6 . 7 | | 8 . . | . 9 2 | . . . | +-------+-------+-------+`

The puzzle has only one solution. It's perfectly valid.

However in the event an invalid puzzle is ever published, it doesn't invalidate the uniqueness test. Had you used other methods on an invalid puzzle, you'd still either end up with an insoluble grid or one that logic could not crack.
Lummox JR

Posts: 125
Joined: 22 September 2005

Lummox JR wrote:The puzzle has only one solution

Which one is it?
Code: Select all
`273965148946138275185724936698371524714259863352846719531687492429513687867492351273965148946138275581724936698371524714259863352846719135687492429513687867492351`

I must have mixed up 1 and 5 somewhere.

Mac
QBasicMac

Posts: 441
Joined: 13 July 2005

Lummox JR wrote:However in the event an invalid puzzle is ever published, it doesn't invalidate the uniqueness test. Had you used other methods on an invalid puzzle, you'd still either end up with an insoluble grid or one that logic could not crack.

sorry, I don't understand.
How can a uniqueness test be useful in puzzles with multiple solutions ?

the posted puzzle has only one solution:
273965148
946138275
158724936
682371594
714259863
395846712
531687429
429513687
867492351

BTW. "how many solutions ?" puzzles are also better for
competitions or puzzles in magazines with a price offered.
You needn't send in the whole puzzle and the result
can be easily checked.
This is what they do with crossword-competition puzzles,
there is usually just a keyword which you have to submit.
9*9 sudokus are already rather big for these sort of puzzle.
Maybe a 6*6 with about 10 solutions is more suitable.
dukuso

Posts: 479
Joined: 25 June 2005

Lummox JR wrote:
Code: Select all
`+-------+-------+-------+| . . . | 9 6 . | . . 8 | | 9 . 6 | . . . | . 7 5 | | . . . | . 2 . | . 3 . | +-------+-------+-------+| . 8 . | . 7 1 | . . 4 | | . . . | . . . | . . . | | 3 . . | 8 4 . | . 1 . | +-------+-------+-------+| . 3 . | . 8 . | . . . | | 4 2 . | . . . | 6 . 7 | | 8 . . | . 9 2 | . . . | +-------+-------+-------+`

Is that the original puzzle, or partially solved? I finished this with nothing harder than naked/hidden singles and naked pairs! Didn't see anything that required a guess and could possibly lead to multiple solutions... unless Lummox JR has added an extra clue to assist?

Code: Select all
` *-----------* |273|965|148| |946|138|275| |158|724|936| |---+---+---| |682|371|594| |714|259|863| |395|846|712| |---+---+---| |531|687|429| |429|513|687| |867|492|351| *-----------*`
Shazbot

Posts: 220
Joined: 24 September 2005

Please accept my profuse apologies for wasting forum space!!!!!

Despite my conviction after multiple cross-checks that I had entered the puzzle correctly, it was nevertheless incorrect. In the original puzzle, r4c2=8. But in my version, r4c2=9. Somehow in verifying the puzzle multiple times, I kept looking at 8 in one place and 9 in another and concluding they were the same. My cataracts are getting worse and worse!

The posted puzzle has only one solution. Feel free to ignore any further "discoveries" I may present.

Anyway, at least I got an extra puzzle to solve.

Mac
QBasicMac

Posts: 441
Joined: 13 July 2005

### re: re-typing

QBasicMac wrote:Despite my conviction after multiple cross-checks that I had entered the puzzle correctly, it was nevertheless incorrect.
In the original puzzle, r4c2=8. But in my version, r4c2=9.
Somehow in verifying the puzzle multiple times, I kept looking at 8 in one place and 9 in another and concluding they were the same.

that's why i hate re-typing

and then trying the OCR feature of Susser?

- Pat

Pat

Posts: 3690
Joined: 18 July 2005

### Re: re: re-typing

Pat wrote:How about Alt-PrintScreen and then trying the OCR feature of Susser?

Too complicated for me. I wish the puzzle page had an option to get the puzzle in ascii. It is a picture.

But thanks for the suggestion. I'll just hobble along with manual copy and resolve not to accuse the site of a bad puzzle without having another pair of eyes verify my copy.

You could do me a favor by creating a blog or something and every day do your OCR stuff and then post the puzzle in "-34 1-5 ..." format. I would consult it every day and others might, too.

Mac

Mac
QBasicMac

Posts: 441
Joined: 13 July 2005

### "The Daily SuDoku" and re-typing

QBasicMac wrote:I wish the puzzle page had an option to get the puzzle in ascii. It is a picture.

You could create a blog or something and every day do your OCR stuff
and then post the puzzle in "-34 1-5 ..." format.
I would consult it every day and others might, too.

sorry, but we'd have to convinceThe Daily SuDoku to post a text version:
they claim copyright on each puzzle!

i've used the screen-shot method on some tough web-sites;
however,today's puzzle is indeed an image
- which means that SuDoku Susser can probably accept it directly!!
(just click the "an image" link above)

{ edit: just click their button "Play Online",
then you'll get a button "Ascii" !! }

Pat

Posts: 3690
Joined: 18 July 2005