Stuck again.

Advanced methods and approaches for solving Sudoku puzzles

Stuck again.

Postby jgraves » Tue Oct 25, 2005 6:34 pm

Thanks again for the help yesterday. I've learned a lot. However, none of the new techniques I learned yesterday seem to work here. Please help.

I'll try to be more careful this time with my post and not miss any numbers!

Original puzzle:
Code: Select all
+---+---+---+
|..9|...|7.5|
|..1|..5|..3|
|.7.|9..|...|
+---+---+---+
|..2|.89|.6.|
|.8.|...|.2.|
|.9.|2..|3..|
+---+---+---+
|...|..2|.4.|
|8..|5..|9..|
|9.7|...|5..|
+---+---+---+


So far I've got:
Code: Select all
+---+---+---+
|..9|...|785|
|..1|875|.93|
|578|9..|.14|
+---+---+---+
|.52|389|.67|
|.8.|.5.|.29|
|.9.|2..|358|
+---+---+---+
|..5|792|84.|
|8..|5..|97.|
|9.7|..8|53.|
+---+---+---+


What I have as an option list:
Code: Select all
+----------------+----------------+----------------+
| 236. 36.. 9... | 146. 1246 146. | 7... 8... 5... |
| 246. 46.. 1... | 8... 7... 5... | 26.. 9... 3... |
| 5... 7... 8... | 9... 236. 36.. | 26.. 1... 4... |
+----------------+----------------+----------------+
| 14.. 5... 2... | 3... 8... 9... | 14.. 6... 7... |
| 1467 8... 3... | 146. 5... 1467 | 14.. 2... 9... |
| 1467 9... 46.. | 2... 146. 1467 | 3... 5... 8... |
+----------------+----------------+----------------+
| 36.. 136. 5... | 7... 9... 2... | 8... 4... 16.. |
| 8... 1246 46.. | 5... 1346 1346 | 9... 7... 126. |
| 9... 1246 7... | 146. 146. 8... | 5... 3... 126. |
+----------------+----------------+----------------+


Thanks.

-John
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Postby emm » Tue Oct 25, 2005 6:50 pm

Simple Sudoku gives this 76 possible solutions ie it's an invalid puzzle. Where did you get it from?
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Postby jgraves » Tue Oct 25, 2005 7:05 pm

Whew. I messed something up then. That makes me feel better.

I got it off the web as a "daily sudoku", but I may have messed up a number somewhere.

Is there a site I can use to validate a sudoku?

Thanks.

-John
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Postby emm » Tue Oct 25, 2005 7:18 pm

http://act365.com/sudoku/ copy puzzle in here and click evaluate
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Postby PaulIQ164 » Tue Oct 25, 2005 7:20 pm

I'd suggest you've missed a number from r6c5, simce that's all that's stopping it being symmetrical.
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Postby QBasicMac » Tue Oct 25, 2005 7:45 pm

jgraves wrote:I got it off the web as a "daily sudoku", but I may have messed up a number somewhere.


The Daily Sudoku gives puzzles as an image. I sure wish they also presented a simple display that can be copied via ctrl-c and pasted into scratch pads.

But in lieu of that, I do this: Enter the puzzle by row. Then check it by column. It's worth the extra effort, considering how much time you lose on an incorrectly copied puzzle!

Mac
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Postby jgraves » Tue Oct 25, 2005 8:11 pm

Thanks for all the tips.
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a lot fewer than 76 solutions

Postby zachbender » Tue Oct 25, 2005 10:48 pm

the puzzle as given lets you get down to ten open squares, mostly involving choices between 1 and 6, some between 4 and 7 or between 6 and 7. if you choose one course, say 6 rather than 7, the 4/7s resolve, and you are left with only six open squares, all choices between 1 and 6. another choice completes the puzzle. true, it is not a valid sukodu, but my limited number theory does not say this is 76 possible choices -- there are only two paths, each with two sub-paths.
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Re: a lot fewer than 76 solutions

Postby Cec » Wed Oct 26, 2005 7:05 am

zachbender wrote:true, it is not a valid sukodu, but my limited number theory does not say this is 76 possible choices -- there are only two paths, each with two sub-paths.


If Simple Sudoku comes up with 76 possible solutions, my money's on 76 solutions.

Bonsai Cec
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Postby emm » Wed Oct 26, 2005 7:30 am

Ahhh - you Aussies, you're so chummy!

Zach, did you do the puzzle as posted above or with the alleged missing clue? Do you think 76 possible solutions might mean that there are 74 more you could find if you looked? How about you post your two and then if we have time we can look for the rest. (fairly optimistic)
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Joined: 02 July 2005

Postby simes » Wed Oct 26, 2005 9:03 am

For those interested, here are the 76 solutions:

Code: Select all
239146785461875293578923614152389467683457129794261358315792846826534971947618532
239146785461875293578923614152389467783654129694217358315792846846531972927468531
239146785641875293578923614152389467483657129796214358315792846864531972927468531
239146785641875293578923614152389467483657129796214358365792841824531976917468532
239146785641875293578923614152389467783654129496217358315792846864531972927468531
239146785641875293578923614152389467783654129496217358365792841824531976917468532
239146785641875293578923614452389167183657429796214358315792846864531972927468531
239146785641875293578923614452389167183657429796214358365792841824531976917468532
239164785461875293578923614152389467683457129794216358315792846846531972927648531
239164785461875293578923614152389467783456129694217358315792846846531972927648531
239164785641875293578923614152389467483657129796241358315792846824536971967418532
239164785641875293578923614152389467483657129796241358365792841814536972927418536
239164785641875293578923614152389467783456129496217358315792846864531972927648531
239164785641875293578923614152389467783456129496217358365792841824531976917648532
239164785641875293578923614452389167183657429796241358315792846824536971967418532
239164785641875293578923614452389167183657429796241358365792841814536972927418536
239164785641875293578923614452389167783651429196247358315792846824536971967418532
239164785641875293578923614452389167783651429196247358365792841814536972927418536
239461785641875293578923614152389467483657129796214358315792846824536971967148532
239461785641875293578923614152389467483657129796214358365792841814536972927148536
239461785641875293578923614152389467783654129496217358315792846824536971967148532
239461785641875293578923614152389467783654129496217358365792841814536972927148536
239461785641875293578923614452389167183657429796214358315792846824536971967148532
239461785641875293578923614452389167183657429796214358365792841814536972927148536
239614785641875293578923614452389167783156429196247358315792846864531972927468531
239614785641875293578923614452389167783156429196247358365792841824531976917468532
239641785461875293578923614152389467683457129794216358315792846826534971947168532
239641785461875293578923614152389467783456129694217358315792846826534971947168532
369124785241875693578936214152389467483657129796241358635792841814563972927418536
369124785241875693578936214152389467483657129796241358635792841824513976917468532
369124785241875693578936214452389167183657429796241358635792841814563972927418536
369124785241875693578936214452389167183657429796241358635792841824513976917468532
369124785241875693578936214452389167783651429196247358635792841814563972927418536
369124785241875693578936214452389167783651429196247358635792841824513976917468532
369124785241875693578963214152389467483657129796241358635792841814536972927418536
369124785241875693578963214152389467783456129496217358635792841824531976917648532
369124785241875693578963214452389167183657429796241358635792841814536972927418536
369124785241875693578963214452389167783651429196247358635792841814536972927418536
369421785241875693578936214152389467483657129796214358635792841814563972927148536
369421785241875693578936214152389467783654129496217358635792841814563972927148536
369421785241875693578936214452389167183657429796214358635792841814563972927148536
369421785241875693578963214152389467483657129796214358635792841814536972927148536
369421785241875693578963214152389467783654129496217358635792841814536972927148536
369421785241875693578963214452389167183657429796214358635792841814536972927148536
639124785241875693578936214152389467483657129796241358315792846824563971967418532
639124785241875693578936214152389467483657129796241358315792846864513972927468531
639124785241875693578936214152389467483657129796241358365792841814563972927418536
639124785241875693578936214152389467483657129796241358365792841824513976917468532
639124785241875693578936214452389167183657429796241358315792846824563971967418532
639124785241875693578936214452389167183657429796241358315792846864513972927468531
639124785241875693578936214452389167183657429796241358365792841814563972927418536
639124785241875693578936214452389167183657429796241358365792841824513976917468532
639124785241875693578936214452389167783651429196247358315792846824563971967418532
639124785241875693578936214452389167783651429196247358315792846864513972927468531
639124785241875693578936214452389167783651429196247358365792841814563972927418536
639124785241875693578936214452389167783651429196247358365792841824513976917468532
639124785241875693578963214152389467483657129796241358315792846824536971967418532
639124785241875693578963214152389467483657129796241358365792841814536972927418536
639124785241875693578963214152389467783456129496217358315792846864531972927648531
639124785241875693578963214152389467783456129496217358365792841824531976917648532
639124785241875693578963214452389167183657429796241358315792846824536971967418532
639124785241875693578963214452389167183657429796241358365792841814536972927418536
639124785241875693578963214452389167783651429196247358315792846824536971967418532
639124785241875693578963214452389167783651429196247358365792841814536972927418536
639421785241875693578936214152389467483657129796214358315792846824563971967148532
639421785241875693578936214152389467483657129796214358365792841814563972927148536
639421785241875693578936214152389467783654129496217358315792846824563971967148532
639421785241875693578936214152389467783654129496217358365792841814563972927148536
639421785241875693578936214452389167183657429796214358315792846824563971967148532
639421785241875693578936214452389167183657429796214358365792841814563972927148536
639421785241875693578963214152389467483657129796214358315792846824536971967148532
639421785241875693578963214152389467483657129796214358365792841814536972927148536
639421785241875693578963214152389467783654129496217358315792846824536971967148532
639421785241875693578963214152389467783654129496217358365792841814536972927148536
639421785241875693578963214452389167183657429796214358315792846824536971967148532
639421785241875693578963214452389167183657429796214358365792841814536972927148536


Simes
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Stuck again

Postby Cec » Wed Oct 26, 2005 9:30 am

simes wrote:For those interested, here are the 76 solutions


See above for space constraints. I tried counting and there's definitely more than two. Are you're sure you didn't get mixed up with Peiderson's batting score cards for the recent "Ashes" series.

Bonsai Cec
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fewer than 76?

Postby zachbender » Thu Oct 27, 2005 12:58 am

em sez:

"How about you post your two and then if we have time we can look for the rest"

Well, of course in the meantime I have discarded my notes. What I am getting on this try is:

-2- -3- (9) [1/4/6] (7) -8- (5)
-4- -6- (1) -8- -7- (5) -2- -9- (3)
-5- (7) -8- (9) -2- -3- -6- -1- -4-

-1- -5- (2) -3- (8) (9) -4- (6) -7-
[6/7] (8) [4/3] --- -5- --- -1- (2) -9-
[6/7] (9) [4/3] (2) [1/5] [1/7] (3) -5- -8-

-3- -1- -5- -7- -9- (2) -8- (4) -6-
(8) [4/2] -6- (5) -3- [4/1] (9) -7- [1/2]
(9) [4/2] (7) --- --- --- (5) -3- [1/2]

I do now recognize that row 7, column 2 was not forced. I needed a 1 in column 2, the other choices were 6 and 3, 1 or 6 had to go into coumn 8, and if the 1 in column 2 went to row 8 or 9, blah, blah, blah. So there is one earlier divergence, reflected in the above.

R.
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Stuck again

Postby Cec » Thu Oct 27, 2005 2:56 am

zachbender wrote:em sez:

"How about you post your two and then if we have time we can look for the rest ......"


Hi zachbender, My name is Cec (not sez)and I assume you are referring to 'em' and me.

Following the above post from Simes which lists the 76 solutions my reference to "more than two" solutions was said with 'tongue in cheek' as I had trouble trying to count the 76 solutions. Because it is an invalid puzzle I made no attempt to solve it.

Cec
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Re: Stuck again

Postby MCC » Thu Oct 27, 2005 10:40 am

cecbevwr wrote:
zachbender wrote:em sez:

"How about you post your two and then if we have time we can look for the rest ......"


Hi zachbender, My name is Cec (not sez)and I assume you are referring to 'em' and me.

Following the above post from Simes which lists the 76 solutions my reference to "more than two" solutions was said with 'tongue in cheek' as I had trouble trying to count the 76 solutions. Because it is an invalid puzzle I made no attempt to solve it.

Cec


Cec, I believe Zach was referring to:

em wrote:Zach, did you do the puzzle as posted above or with the alleged missing clue? Do you think 76 possible solutions might mean that there are 74 more you could find if you looked? How about you post your two and then if we have time we can look for the rest. (fairly optimistic)


mcc
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