So much for the Uniqueness idea!

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So much for the Uniqueness idea!

Postby QBasicMac » Sat Dec 03, 2005 4:52 am

Saturday, Dec 3

Two solutions?

Mac
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Postby Lummox JR » Sat Dec 03, 2005 5:09 am

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.
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Postby QBasicMac » Sat Dec 03, 2005 5:26 am

Lummox JR wrote:The puzzle has only one solution


Which one is it?
Code: Select all
273965148946138275185724936698371524714259863352846719531687492429513687867492351
273965148946138275581724936698371524714259863352846719135687492429513687867492351


I must have mixed up 1 and 5 somewhere.

Mac
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Postby dukuso » Sat Dec 03, 2005 6:26 am

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.
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Postby Shazbot » Sat Dec 03, 2005 7:31 am

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|
 *-----------*
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Postby QBasicMac » Sat Dec 03, 2005 2:18 pm

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
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re: re-typing

Postby Pat » Sun Dec 04, 2005 3:03 pm

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

how about Alt-PrintScreen
and then trying the OCR feature of Susser?

- Pat
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Re: re: re-typing

Postby QBasicMac » Mon Dec 05, 2005 5:23 pm

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
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"The Daily SuDoku" and re-typing

Postby Pat » Mon Dec 05, 2005 6:08 pm

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" !! }
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