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stuck in this sudoku
   LMI Essentials -> Solving Techniques159 posts • Page 1 of 7 • 1 2 3 4 5 6 7
Administrator
Subject: Re: stuck in this sudoku @ 2012-09-21 9:15 PM (#8612 - in reply to #8611) (#8612) Top


20001000500202020
Location: India
Hi Kishore, After uploading the image in http://tinypic.com you will get "HTML for Websites".
Copy that and paste in your post.

"HTML for Websites" will look like : <a href="http://tinypic.com?ref=1zn20so" target="_blank"><img src="http://i47.tinypic.com/1zn20so.png" border="0" alt="Image and video hosting by TinyPic"></a>

You can also copy and paste "Direct Link for Layouts" which looks like : http://i47.tinypic.com/1zn20so.png
kishy72
Subject: RE: stuck in this sudoku @ 2012-09-21 9:24 PM (#8613 - in reply to #8611) (#8613) Top


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i am posting the link...thnks deb.i could not have posted this without your help.

Administrator
Subject: Re: stuck in this sudoku @ 2012-09-21 9:51 PM (#8614 - in reply to #8613) (#8614) Top


20001000500202020
Location: India
Focus on R7C2 and R9C2 and column 2. You should be able find the next steps.

Spoiler: show
Given that you have already marked R2C2 and R8C2 as 78, R7C2 and R9C2 have naked pair 36. So R5C3 is 6 and R5C2 is 9.


Edited by debmohanty 2012-09-21 10:05 PM
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-22 11:44 AM (#8621 - in reply to #8614) (#8621) Top


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Administrator - 2012-09-21 9:51 PM

Focus on R7C2 and R9C2 and column 2. You should be able find the next steps.

Spoiler: show
Given that you have already marked R2C2 and R8C2 as 78, R7C2 and R9C2 have naked pair 36. So R5C3 is 6 and R5C2 is 9.


hi i m not getting it.How did u lock (3/6)in (R7C2 /R9C2).(3 and 6) eliminated from R2C2,R3C2,R4C2-perfectly ok.But only 3 is getting eliminated from R5C2 .So 6 might be present in R5C2 right?!correct me if i am missing something.
prasanna16391
Subject: Re: stuck in this sudoku @ 2012-09-22 12:14 PM (#8622 - in reply to #8621) (#8622) Top


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kishy72 - 2012-09-22 11:44 AM

Administrator - 2012-09-21 9:51 PM

Focus on R7C2 and R9C2 and column 2. You should be able find the next steps.

Spoiler: show
Given that you have already marked R2C2 and R8C2 as 78, R7C2 and R9C2 have naked pair 36. So R5C3 is 6 and R5C2 is 9.


hi i m not getting it.How did u lock (3/6)in (R7C2 /R9C2).(3 and 6) eliminated from R2C2,R3C2,R4C2-perfectly ok.But only 3 is getting eliminated from R5C2 .So 6 might be present in R5C2 right?!correct me if i am missing something.


In the bottom left box, the only digits that can be there are 3,6,7,8 right? Now in C2, you already have a place in R2 for 7-8, and R8 for 7-8. So 7-8 can't be in any of the rest of the cells in C2. So, R7 and R9 of C2 cannot have 7-8, and the only remaining digits that are possible from the original 4 is 3 and 6.
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-22 1:44 PM (#8625 - in reply to #8622) (#8625) Top


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So basically R9C3 contains either 7 or 8 and therefore......................clear now . will be posting many more stuck sudokus .Thanks guys!
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-23 8:09 PM (#8642 - in reply to #8611) (#8642) Top


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second in the list of sudokus ....where i m unable to cross beyond this point ...fatigue sets in after a certain point...not able to lock any number after this ....

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Subject: Re: stuck in this sudoku @ 2012-09-23 8:28 PM (#8643 - in reply to #8611) (#8643) Top


20001000500202020
Location: India
Where do you put 2 in column 3?

Spoiler: show
Given that you have already marked triplets 2/3/4 in row 3 (C5,C8,C9), R3C3 can not be 2


It should solve pretty smoothly after that.
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-23 9:33 PM (#8644 - in reply to #8643) (#8644) Top


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Administrator - 2012-09-23 8:28 PM

Where do you put 2 in column 3?

Spoiler: show
Given that you have already marked triplets 2/3/4 in row 3 (C5,C8,C9), R3C3 can not be 2


It should solve pretty smoothly after that.

Beautiful!i completed very fast after putting that number...great spotting!...hope i remember these small intricacies and implement them in future sudokus.thnk u !
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-25 4:15 PM (#8660 - in reply to #8611) (#8660) Top


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third in the series of stuck sudokus...
how do i proceed from here fellas?!

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prasanna16391
Subject: Re: stuck in this sudoku @ 2012-09-25 4:59 PM (#8661 - in reply to #8611) (#8661) Top


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R1C6 can only be 5-7 due to normal single eliminations of 3,6,2. Similarly, R1C5 can only be 2-5-7. As you have already marked R1C9 as 5-2, that makes a triplet meaning 7 can only be in R1C5/6. It can also only be in R5C5/6, as you have marked. So in C4, you get just one spot to place the 7.
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-25 7:49 PM (#8662 - in reply to #8661) (#8662) Top


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prasanna16391 - 2012-09-25 4:59 PM

R1C6 can only be 5-7 due to normal single eliminations of 3,6,2. Similarly, R1C5 can only be 2-5-7. As you have already marked R1C9 as 5-2, that makes a triplet meaning 7 can only be in R1C5/6. It can also only be in R5C5/6, as you have marked. So in C4, you get just one spot to place the 7.


amazing ..and here was i under the false assumption all these years that all it takes to solve a sudoku is a set of simple rules and logic when the tricks to be learnt in the trade is endless....i know i certainly wouldn't have placed that 7 after making that deduction of locking it in R1C5/R1C6....i m learning new tricks in sudoku ....all the 3 sudokus i failed to solve has some triplets...!!!!!i feel i m improving gradually after joining LMI....thnks prasanna!

Edited by kishy72 2012-09-25 7:50 PM
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-27 11:05 PM (#8673 - in reply to #8611) (#8673) Top


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4th in the series ..help me out on this one fellas....hope u guys are not too busy in prep for wc...i am sure i combed the entire sudoku for triplets and could not notice anyImage and video hosting by TinyPic

Edited by kishy72 2012-09-27 11:05 PM
prasanna16391
Subject: Re: stuck in this sudoku @ 2012-09-27 11:34 PM (#8674 - in reply to #8611) (#8674) Top


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I remember how I solved this one(thats a rarity, I generally struggle to re-solve things).

Anyway, see R2 and R8. whichever way you see it, R2/8C6 has to be 1/3. Should be simple to see, say 1 and 3 are in R2C4 and C5, then both have to be in R8C6, and vice versa. So R7C6 has to be 6.
akash.doulani
Subject: Re: stuck in this sudoku @ 2012-09-28 12:34 PM (#8681 - in reply to #8611) (#8681) Top


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there is a triplet of 458 in r1r3r5/c6. after that u get a 6 in r7c6. its plain solving after that
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-28 1:02 PM (#8683 - in reply to #8681) (#8683) Top


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akash.doulani - 2012-09-28 12:34 PM

there is a triplet of 458 in r1r3r5/c6. after that u get a 6 in r7c6. its plain solving after that


Yes indeed. I could not spot that...
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-28 1:11 PM (#8684 - in reply to #8611) (#8684) Top


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A general query guys....is it advisable to put more than 2 possible numbers in a box? Initially i was not in the habit of putting possible numbers in a box.In fact i hated that since i felt it made the whole sudoku very clustered.But i have realised that it is impossible to solve sudokus of greater difficulty without making a note of the possible numbers that occur in a box.But still is it advisable to write 3-4 numbers in a box and try to solve it if u get stuck, or to just write numbers where you get only 2 after eliminating the rest..This is something which i had always wanted to know from others because even after putting 2, i have got stuck in many a sudoku and the whole thing gets clear only when i put 3 numbers ...want to be sure that sudokus can be solved without writing more than 2 possible numbers in the box....ideas are welcome...
prasanna16391
Subject: Re: stuck in this sudoku @ 2012-09-28 3:57 PM (#8687 - in reply to #8611) (#8687) Top


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Its about the method that suits you best. Personally, I don't like using pencil marks at all. I do better on sites without pencil marks, and I try but I can't stop myself from using them subconsciously when they are there as a part of the interface(been trying to). I've talked to others though and the normal thing is to note down numbers to keep track. So I suppose you'll find this way easier. The difficult ones need a lot of pencil marks, because to add difficult tricks, the creator would have to use a larger group of numbers in the grid and solving them requires an understanding of that entire group. So there's nothing wrong in entering 4-5 pencil marks in a cell as long as you don't end up confusing yourself(which is my problem and why I'm faster without that).

Edited by prasanna16391 2012-09-28 3:58 PM
akash.doulani
Subject: Re: stuck in this sudoku @ 2012-09-28 9:38 PM (#8689 - in reply to #8611) (#8689) Top


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@ kishore : from where do you get those sudokus ? they are pretty interesting to solve. can you share the source ?
kishy72
Subject: Re: stuck in this sudoku @ 2012-09-28 10:56 PM (#8690 - in reply to #8689) (#8690) Top


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I take them from fed sudoku...choose puzzle blogs from LMI home screen -->Fedsudoku--->sudoku archive--->classic printable....
They are my daily dosage of tablets for improving sudoku skills.
prasanna16391
Subject: Re: stuck in this sudoku @ 2012-09-28 11:32 PM (#8691 - in reply to #8690) (#8691) Top


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kishy72 - 2012-09-28 10:56 PM

I take them from fed sudoku...choose puzzle blogs from LMI home screen -->Fedsudoku--->sudoku archive--->classic printable....
They are my daily dosage of tablets for improving sudoku skills.


Akash is a regular there, he's just not been able to do them lately so didn't know I suppose. Anyway, I'm a regular there too. There's other sites as well with daily sudokus like Sudokucup, mindoku. These 3 are my daily routine anyway. Related to your earlier pencil marks question, mindoku's interface doesn't have pencil marks.
kishy72
Subject: Re: stuck in this sudoku @ 2012-10-06 9:51 PM (#8735 - in reply to #8691) (#8735) Top


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the way please in this
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Edited by kishy72 2012-10-06 9:57 PM
kishy72
Subject: Re: stuck in this sudoku @ 2012-10-06 9:53 PM (#8736 - in reply to #8735) (#8736) Top


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oh my !!!!
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Subject: Re: stuck in this sudoku @ 2012-10-08 8:52 PM (#8739 - in reply to #8736) (#8739) Top


20001000500202020
Location: India
Just by going the marks you have done (and assuming that they are correct), where do you put 3 in Box2?

However, I think you have gone wrong somewhere. I couldn't resolve the bottom 3 rows so early in the solve.
kishy72
Subject: Re: stuck in this sudoku @ 2012-10-08 9:31 PM (#8740 - in reply to #8611) (#8740) Top


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Posts: 419
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i have addled the sudoku so much that i could not see that direct spotting...and yes i have gone wrong. I started from the beginning again and i saw where i went wrong ....Thnks deb!
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