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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Thu Oct 15, 2009 10:09 pm Post subject: Decabit Insane October 15 |
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For me, the first move was the hardest.
Code: |
+-------+-------+-------+
| . . 7 | 3 . . | . . . |
| . . . | . 8 4 | . 5 . |
| 4 . 5 | . . . | 7 8 . |
+-------+-------+-------+
| . 8 . | . . 5 | 2 . . |
| . . 3 | 4 . 8 | . . . |
| 2 . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . 6 | . 4 2 |
| . . . | . . . | 1 . 7 |
| . 1 . | . . 3 | . 6 5 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site
Ted |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Thu Oct 15, 2009 11:49 pm Post subject: |
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Code: | .------------------------.------------------------.------------------------.
| 8 69 7 | 3 5 19 | 469 2 1469 |
| 1369 2369 1269 | 7 8 4 | 369 5 369 |
| 4 39 5 | 269 69 129 | 7 8 139 |
:------------------------+------------------------+------------------------:
| 1679 8 1469 | 169 1369 5 | 2 1379 3469 |
| 15679 5679 3 | 4 2 8 | 569 179 69 |
| 2 4569 1469 | 169 1369 7 | 34569 139 8 |
:------------------------+------------------------+------------------------:
| 3579 3579 89 | 1589 179 6 | 389 4 2 |
| 3569 234569 24689 | 2589 49 *29 | 1 39 7 |
| 79 1 2489 |*289 479 3 |*89 6 5 |
'------------------------'------------------------'------------------------' |
xyz-wing removes 9 from r9c5
Code: | +-----------------------+-------------------+-------------------+
| 8 69 7 | 3 5 19 | 469 2 1469 |
| 1369 2369 1269 | 7 8 4 | 369 5 369 |
| 4 39 5 | 269 69 129 | 7 8 139 |
+-----------------------+-------------------+-------------------+
| 1679 8 1469 | 169 1369 5 | 2 1379 3469 |
| 15679 5679 3 | 4 2 8 | 569 179 69 |
| 2 4569 1469 | 169 1369 7 | 34569 139 8 |
+-----------------------+-------------------+-------------------+
| 3579 3579 89 | 1589 179 6 | 389 4 2 |
| 3569 234569 24689 | 2589 (49) 29 | 1 39 7 |
| 79 1 89(24) | 8-9(2) 7(4) 3 | 89 6 5 |
+-----------------------+-------------------+-------------------+ |
(9=4)r8c5 - (4)r9c5 = (4-2)r9c3 = (2)r9c4; r9c4 <> 9
Code: | +----------------------+------------------+-------------------+
| 8 69 7 | 3 5 19 | 469 2 1469 |
| 1369 2369 1269 | 7 8 4 | 369 5 369 |
| 4 39 5 | 269 69 129 | 7 8 139 |
+----------------------+------------------+-------------------+
| 1679 8 1469 | 169 1369 5 | 2 1379 3469 |
| 15679 5679 3 | 4 2 8 | 569 179 69 |
| 2 4569 1469 | 169 1369 7 | 34569 139 8 |
+----------------------+------------------+-------------------+
| 3579 3579 89 | 1589 179 6 | 389 4 2 |
| 3569 234569 24689 | 2589 49 (29) | 1 3-9 7 |
| 79 1 2489 | (28) 47 3 | (89) 6 5 |
+----------------------+------------------+-------------------+ |
xy-wing finishes {2,8,9} |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Fri Oct 16, 2009 11:36 am Post subject: |
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I also had three moves to complete this puzzle.
The first move was the xyz-wing noted by Norm; it took me a while to spot it and I did not find any other VH type moves. This step deleted the 9 from r9c5, which opened up a
xy-wing 47-9 with vertex 47 in r9c5 and pincers in r8c5 & r9c1 which deleted the 9 in r9c4, which was the same as Norm's short chain, plus the 9s in r8c123. This move then opened up a
xy-wing 28-9, which again was identical to the move by Norm.
I wonder if this puzzle has other VH solutions
Ted |
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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Fri Oct 16, 2009 2:56 pm Post subject: insane |
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If you use the 479 xyz-wing to remove 9 from R9C4, it opens a 289 xy-wing, solving the puzzle in two steps.
Earl |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Fri Oct 16, 2009 5:08 pm Post subject: Re: insane |
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Earl wrote: | If you use the 479 xyz-wing to remove 9 from R9C4, it opens a 289 xy-wing, solving the puzzle in two steps.
Earl |
Very nice Earl |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Fri Oct 16, 2009 9:00 pm Post subject: |
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Did you notice that, after basics, EVERY unsolved cell could be 9? In other words, no solved cells are 9.
Keith |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Sat Oct 17, 2009 4:24 am Post subject: |
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I noticed that with the 9s. I also used eight moves. Then I noticed a triple which may have been there before the moves, but, what the heck, I finished it. |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Sat Oct 17, 2009 4:45 am Post subject: |
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Marty R. wrote: | I noticed that with the 9s. I also used eight moves. Then I noticed a triple which may have been there before the moves, but, what the heck, I finished it. |
Well Marty, you answered my question: Yes this puzzle has multiple VH solutions.
Ted |
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wapati
Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
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Posted: Sat Oct 17, 2009 7:04 am Post subject: |
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tlanglet wrote: |
I wonder if this puzzle has other VH solutions
Ted |
What are the VH methods?
Is there a listing on-site?
Thanks. |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Sat Oct 17, 2009 11:38 am Post subject: |
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wapati wrote: | What are the VH methods?
Is there a listing on-site?
Thanks. |
Don't know about a listing. Also, I think what is meant by "VH methods" is really "methods to solve this site's VH puzzles". And to that question, the answer (from my experience) is:
To solve "Very Hard" puzzles from dailysudoku.com, you need nothing more than x-wing, xy-wing and xyz-wing |
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wapati
Joined: 10 Jun 2008 Posts: 472 Location: Brampton, Ontario, Canada.
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Posted: Sat Oct 17, 2009 10:56 pm Post subject: |
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nataraj wrote: | wapati wrote: | What are the VH methods?
Is there a listing on-site?
Thanks. |
Don't know about a listing. Also, I think what is meant by "VH methods" is really "methods to solve this site's VH puzzles". And to that question, the answer (from my experience) is:
To solve "Very Hard" puzzles from dailysudoku.com, you need nothing more than x-wing, xy-wing and xyz-wing |
Thanks. |
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