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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Mon Jul 23, 2007 2:37 am Post subject: Truly VH |
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Since todays VH went too smoothly, I found one that was truly VH.
Any one see the next move?
I see forcing chains, but prefer a cleaner solution path.
Earl
Code: |
+-------------+--------------+-----------+
| 3 9 1 | 8 27 4 | 67 267 5 |
| 5 4 8 | 67 3 26 | 1 27 9 |
| 2 7 6 | 1 5 9 | 4 3 8 |
+-------------+--------------+-----------+
| 1 56 4 | 9 8 7 | 2 56 3 |
| 8 2356 35 | 4 12 123 | 569 569 7 |
| 7 23 9 | 5 6 23 | 8 4 1 |
+-------------+--------------+-----------+
| 49 8 357 | 3467 47 356 | 579 1 2 |
| 6 135 2 | 37 9 135 | 57 8 4 |
| 49 15 57 | 2 147 8 | 3 579 6 |
+-------------+--------------+-----------+
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Play this puzzle online at the Daily Sudoku site
Last edited by Earl on Mon Jul 23, 2007 9:40 pm; edited 3 times in total |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Mon Jul 23, 2007 4:09 am Post subject: |
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XY-Wing based in box 8, but don't know how far it takes you. |
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jLo
Joined: 30 Apr 2007 Posts: 55
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Posted: Mon Jul 23, 2007 2:19 pm Post subject: Re: Truly VH |
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Earl wrote: | Since todays VH went too smoothly, I found one that was truly VH.
Any one see the next move?
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How did you eliminate 5 for R5C8? |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Mon Jul 23, 2007 2:32 pm Post subject: Truly VH |
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Oops!
That makes it very truly VH!
Earl |
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jLo
Joined: 30 Apr 2007 Posts: 55
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Posted: Mon Jul 23, 2007 7:43 pm Post subject: Re: Truly VH |
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Earl wrote: | Oops!
That makes it very truly VH!
Earl |
After doing Marty's XY-wing and a skyscraper on <7>s to eliminate
<7> from R1C7, you end up here -
Code: |
+-------------+-------------+-----------+
| | 27 | 27 |
| | 67 26 | 27 |
| | | |
+-------------+-------------+-----------+
| 56 | | 56 |
| 2356 35 | 12 123 | 59 569 |
| 23 | 23 | |
+-------------+-------------+-----------+
| 49 357 | 367 47 56 | 579 |
| 135 | 37 15 | 57 |
| 49 15 57 | 147 | 59 |
+-------------+-------------+-----------+
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From there, I started coloring <3>s at R8C4 -
Code: |
+-------------+-------------+-----------+
| | 27 | 27 |
| | 67 26 | 27 |
| | | |
+-------------+-------------+-----------+
| 56 | | 56 |
| 2356 35 | 12 123 | 59 569 |
| 23 | 23 | |
+-------------+-------------+-----------+
| 49 +357 |-367 47 56 | 579 |
| 1-35 |+3-7 15 | 57 |
| 49 15 57# | 147 | 59 |
+-------------+-------------+-----------+
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I noticed that if <+> is true, then R8C2/R9C2 becomes a nake pair <15> and R9C3=7
if <-> is true, then R8C4=7 and R9C3=7 (only 7 left for the row).
Therefore, R9C3=7
From there, an X-wing on <5>s and an XY-Wing from Box 7 take you home. |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Mon Jul 23, 2007 7:45 pm Post subject: |
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Earl,
There is still a bit of basic cleanup to do. Look at <4>s in C4 and <3>s in C46. That won't really get you anywhere obvious that I can see, though.
I don't see Marty's XY-Wing.
However, there is a Finned X-Wing on 5.
And, there is a Skyscraper on 7.
After that, there are various XY-Chains available, if those are okay with you. I tried one that targets R7C1. Alternately, I tried another that targets R5C8. Either one led to an X-Wing on 5 and a W-Wing on 37 that solved the rest. |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Mon Jul 23, 2007 9:24 pm Post subject: |
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Quote: | I don't see Marty's XY-Wing. |
Apparently Jlo's comment made Earl realize that his original grid was incorrect, and when he edited his post the XY-Wing disappeared. |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Mon Jul 23, 2007 9:38 pm Post subject: Truly VH |
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Asellus,
Thanks for the tips.
An xy-chain based in R9C2 eliminated the 5 in R9C8 and opened the puzzle for me. But I have trouble spotting xy-chains.
Thanks
Earl |
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jLo
Joined: 30 Apr 2007 Posts: 55
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Posted: Mon Jul 23, 2007 11:40 pm Post subject: |
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I'm not seeing any of these X-Y chains before 5 is eliminated from R5C8.
Someone give me a clue. |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Tue Jul 24, 2007 1:24 am Post subject: |
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jLo,
After the basic simplifications, Finned X-Wing and Skyscraper, the puzzle looks like this:
Code: | +-------------+-------------+-----------+
| 3 9 1 | 8 27 4 | 6 27 5 |
| 5 4 8 | 67 3 26 | 1 27 9 |
| 2 7 6 | 1 5 9 | 4 3 8 |
+-------------+-------------+-----------+
| 1 56 4 | 9 8 7 | 2 56 3 |
| 8 2356 35 | 4 12 123 | 59 569 7 |
| 7 23 9 | 5 6 23 | 8 4 1 |
+-------------+-------------+-----------+
| 49 8 357 | 367 47 56 | 579 1 2 |
| 6 13 2 | 37 9 15 | 57 8 4 |
| 49 15 57 | 2 147 8 | 3 59 6 |
+-------------+-------------+-----------+ |
Earl's XY-Chain has pincers R9C2 and R8C7 and is only 4 cells long.
One of mine has pincers R9C1 and R7C5 and is more than 4 cells long. The other has pincers R5C7 and R9C8, does not eliminate your pesky 5, and is also more than 4 cells long.
Let me know if you need more clues. |
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jLo
Joined: 30 Apr 2007 Posts: 55
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Posted: Tue Jul 24, 2007 4:13 am Post subject: |
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Asellus wrote: | jLo,
Let me know if you need more clues.
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Thanks, I see it now.
I had not seen the finned X-wing, so I still had a <5> at R8C2 that was
killing all three of those chains. |
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