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Tough Sudoku for 31/October/2009


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Sudoku Solving Techniques

Submitted by: sudoku lover

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Totally amazing!!!
Should hire those worms...they do good work!
31/Oct/09 12:30 AM
If this weren't the work of worms, I'd hate to see the HUGE wasps that would come out of this!
31/Oct/09 2:03 AM
Have a great weekend, everyone, and
31/Oct/09 2:03 AM
Interesting picture Kate!!
31/Oct/09 2:50 AM
Yeah, I'd call that wormed... sheesh!
31/Oct/09 4:48 AM
29:36, nice one Kate. Hi everyone.
31/Oct/09 8:06 AM
Kate just has an eye! Thanks
31/Oct/09 8:54 AM
31/Oct/09 10:44 AM

Start at 23 note pairs 19 at a7, c8, c1,
I am sure there are better solutions but since noone has posted one here goes.

Start at 23 note pairs 19 at a7, c8, c1,
Up to 27 note pairs 35 at be6 and therefore 69 at fi6
If f6=9, i6=6, i5=9, i9=2, e9=7,f9=8,f7=3, e7=5 More...
31/Oct/09 4:05 PM
re the wood worm... yesterday I saw a tree that had come crashing down on to a dirt road due to the white ants taking one too many bites ... and today on another back road we saw another.
31/Oct/09 4:09 PM
1) Start at 23,basic techniques to UP=27
3)Loop:(6)a2=f2=f6=i6-(6 =2)i9-ef9=d8-(2=8)d1-(8=6)f2
4) (8=6)f2-f6=i6-(6=2)i9-i3=(2)g2,=>f2<>8
5) More...
31/Oct/09 4:50 PM
Hi fii.I followed your chain,but got d7=8 and 19 fits into ai7.
After UP27,I used a chain, which overlaps yours as follows:
If c3=6=f2=i6,i5=9=f6,b6=3,e6=5,i9=2 and top middle box is devoid of 2 (d78 contains 59).Hence c3=5.UPs to 81.
01/Nov/09 12:01 AM
Sorry fii.My mistake.As you say,ad7 does contain 19,leaving i7 with no candidate.We seem to have used different parts of the same chain to find a contradiction.
01/Nov/09 1:12 AM
01/Nov/09 3:06 AM
Hi Sotir,

I’m having trouble with your step 4. I’ll admit I can barely decipher Eureka, but I can usually work out what it says and does. Is “=>f2<>8" a typo? If you meant f2<>2, I have 2 already eliminated from f2. If it was supposed to be f2<>6, could you More...
04/Nov/09 8:12 AM
Thanks Brenda, you are right.Typo,step 4 =>f2<>8 to
read =>g2<>8. (note: np(25)bg2,hp(48)g79).
Best Regards,Sotir
05/Nov/09 10:25 AM
Thanks, Sotir. Neil clued me in on that, actually. Funny how sometimes one (me anyhow) can't see the most obvious things.

Speaking of which, in step 6) Shouldn't your last step be either i6<>6 or i6=9?

Thanks for all your XY and YW solutions. I'm trying to learn how to spot them.

Much regards,
06/Nov/09 2:29 AM
Thanks again Brenda,
Another typo for step 6, should read i6<>6.
06/Nov/09 4:55 AM

10/Sep/10 7:20 AM
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