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Jan 30 VH
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Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

PostPosted: Sat Jan 30, 2010 4:43 am    Post subject: Jan 30 VH Reply with quote

I needed a one-two punch. Norm, please find a single blow.

A Solution: x-wing (5), then xy-wing (168)


Early Earl
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sat Jan 30, 2010 4:50 am    Post subject: Reply with quote

Could I have screwed up twice? (Of course). I finished it with basics only both times.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sat Jan 30, 2010 6:41 am    Post subject: Reply with quote



overkill

(6=5)r3c5 - (5)r13c4 - (5)r8c4 - UR46[(5)r8c6 = (7)r7c3] - (7=6)r7c3 - (6)r5c3 = (6)r5c56;
r6c5 <> 6
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Clement



Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania

PostPosted: Sat Jan 30, 2010 7:09 am    Post subject: Reply with quote

The XYZ-Wing <16>-<156>-<56> which eliminates 6 in r5c6 followed by the
x-wing 5 also soves it.
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Clement



Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania

PostPosted: Sat Jan 30, 2010 7:11 am    Post subject: Reply with quote

The XYZ-Wing <16>-<156>-<56> which eliminates 6 in r5c6 followed by the
x-wing 5 also solves it.
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sat Jan 30, 2010 12:29 pm    Post subject: Reply with quote

I used the XYZ-Wing <156> followed by colouring on <6>. There's a Type 6 UR on <46> but I don't think it is useful.
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George Woods



Joined: 28 Mar 2006
Posts: 304
Location: Dorset UK

PostPosted: Sat Jan 30, 2010 12:29 pm    Post subject: not very satisfactory one stepper Reply with quote

The much despised DR gives a one stepper. if R2c8 is 9, r1c2 is 5 & a 16 DR is revealed so r2c2 is 9 ..... Interestingly kowing that r2c8 is not 9 - setting it to 9 fairly quicky gives not only the DR but a more direct failure! i.e maybe one doesn't have to rely on the DR!
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sat Jan 30, 2010 5:10 pm    Post subject: Reply with quote

Another one stepper:
Code:
 *--------------------------------------------------*
 | 8    15   4    | 25   9    3    | 12   7    6    |
 | 16   169  2    | 4    8    7    | 3    19   5    |
 | 7    359  35   | 256  56   1    | 4    29   8    |
 |----------------+----------------+----------------|
 | 16   156  9    | 7    4    568  | 28   26   3    |
 | 3    2    56   | 9    156  568  | 18   4    7    |
 | 4    78   78   | 3    16   2    | 5    16   9    |
 |----------------+----------------+----------------|
 | 5    467  67   | 8    2    46   | 9    3    1    |
 | 9    46   1    | 56   3    456  | 7    8    2    |
 | 2    38   38   | 1    7    9    | 6    5    4    |
 *--------------------------------------------------*
(2)r1c7 = (2-8)r4c7 = (8-5)r4c6 = (5)r4c2 - (5)r1c2 = (5-2)r1c4 = (2)r3c4 => r1c4<>2
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Wendy W



Joined: 04 Feb 2008
Posts: 144

PostPosted: Sun Jan 31, 2010 1:21 am    Post subject: Reply with quote

Marty, I did it twice with basics only, too. I thought I just got lucky the first time so I tried again. Same thing.
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun Jan 31, 2010 1:36 am    Post subject: Reply with quote

Wendy W wrote:
Marty, I did it twice with basics only, too. I thought I just got lucky the first time so I tried again. Same thing.

That's what I like to hear: we're right and the rest of the world is wrong!! Laughing
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sun Jan 31, 2010 8:32 am    Post subject: Reply with quote

alright you two who solved it with just basics.
maybe you can write up a play by play??

something like.
r2c3 is 6
r1c9 is 7

naked pair here,

naked pair there,

etc... etc.... etc....

or at least post the grid where the puzzle falls to only singles.
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun Jan 31, 2010 5:11 pm    Post subject: Reply with quote

Quote:
alright you two who solved it with just basics.
maybe you can write up a play by play??

I'll stipulate that I screwed up twice based on the fact that too many people needed more than basics.
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George Woods



Joined: 28 Mar 2006
Posts: 304
Location: Dorset UK

PostPosted: Sun Jan 31, 2010 6:08 pm    Post subject: Reply with quote

arkietech gives reasoning:_

(2)r1c7 = (2-8)r4c7 = (8-5)r4c6 = (5)r4c2 - (5)r1c2 = (5-2)r1c4 = (2)r3c4 => r1c4<>2

I have tried to a) understand this and b) Since I didn't understan it to find a primer for the language.

Th Logic might be the equivalent of:- putting a 1 at r1c7, gives r5c7 as 8, r4c6as 8 r4c2 as 5 and r1c2 is 1 - diaster two 1s in row 1 so initial postulate is false so r1c7 is 2

I don't quite see the equivalence of this to the quoted text

Can anyone direct me to a page that defines this nomenclature!
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Sun Jan 31, 2010 6:25 pm    Post subject: Reply with quote

Personally - that nomenclature is not my cup of tea anyway. Looks more like computer proramming. Takes things from the level of fun to pain.
But I guess - one man's meat.....etc
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sun Jan 31, 2010 6:35 pm    Post subject: Reply with quote

George Woods wrote:
arkietech gives reasoning:_

(2)r1c7 = (2-8)r4c7 = (8-5)r4c6 = (5)r4c2 - (5)r1c2 = (5-2)r1c4 = (2)r3c4 => r1c4<>2

I have tried to a) understand this and b) Since I didn't understan it to find a primer for the language.

Th Logic might be the equivalent of:- putting a 1 at r1c7, gives r5c7 as 8, r4c6as 8 r4c2 as 5 and r1c2 is 1 - diaster two 1s in row 1 so initial postulate is false so r1c7 is 2

I don't quite see the equivalence of this to the quoted text

Can anyone direct me to a page that defines this nomenclature!

George,
Google Eureka Notation or look it up in wiki. They have a good description but it takes some study -- or did for me.

Bottom line -- due to alternating inferences r1c7 and/or r3c4 will be a 2 therefore r1c4 cannot be a 2

Hope this helps.
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Wendy W



Joined: 04 Feb 2008
Posts: 144

PostPosted: Sun Jan 31, 2010 7:23 pm    Post subject: Reply with quote

I join Marty in that stipulation! Whether we both made a lucky "erasure" or what, I don't know, but I just tried to write it out step by step (what else is there to do, no football on this afternoon) and in fact couldn't do it this time with basics alone. Darn it!
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sudocraz



Joined: 28 Apr 2008
Posts: 53

PostPosted: Tue Feb 02, 2010 12:53 am    Post subject: Reply with quote

I got this with basics too, but my husband didn't. I must have made a lucky error somewhere because when I did it over I needed an x-wing and an xy wing to get it. Embarassed
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Stanley P



Joined: 27 Feb 2008
Posts: 20
Location: Tennessee, USA

PostPosted: Tue Feb 02, 2010 5:35 am    Post subject: Reply with quote

Interesting comments here so I thought I would add mine. I don't understand the nomenclature (yet) so went at it this way:

I got to Norm's post pretty quickly. Looking at r3c8, making it 2 gives a 6 in r4c8 and making it a 9 gives a 6 in r2c1. So, r4c1 is 1.

Then, using r4c2, making it a 6 puts a 2 in r4c8 and making it a 5 puts a 2 in r1c7. Therefore, r3c8 must be a 9, and that solved it for me.

These moves might be "basics" but they do have the flavor of wings of some sort. Of course, George's DR or his use of r2c8 are another way to get to the solution using what are pretty much basics.

This one was a little different for a VH.
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Tue Feb 02, 2010 1:57 pm    Post subject: Reply with quote

Stan: That looks like guessing - or trial and error - which is a NoNo for VH puzzles. You should learn some of the VH techniques - wings and things. I used this: http://www.sudocue.net/guide.php but there may be others.

Cheers, Craig
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Stanley P



Joined: 27 Feb 2008
Posts: 20
Location: Tennessee, USA

PostPosted: Wed Feb 03, 2010 3:07 am    Post subject: Reply with quote

Hey Craig,
I'm feeling a little defensive in that I used the 156 XYZ wing to get to Norm's post, and I feel pretty good about XYs and X wings. I guess I just couldn't see the X wing others mention as the solution. I still don't see how so many got there with just "basics."
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