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Earl
Joined: 30 May 2007 Posts: 677 Location: Victoria, KS
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Posted: Tue Mar 17, 2009 3:55 am Post subject: March 17 VH |
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St. Patrick's Day brings an impish VH. This leprechaun found the pot gold at the end of the rainbow to be an xyz wing (259). There are alternate paths to the prize, such as a swordfish.
Early Earl |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Tue Mar 17, 2009 4:19 am Post subject: |
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Same XYZ here, but I first played a UR, not because it was needed, but because it was there.
Tardy Marty |
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sdq_pete
Joined: 30 Apr 2007 Posts: 119 Location: Rotterdam, NL
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Posted: Tue Mar 17, 2009 1:23 pm Post subject: |
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It was a XY for me. I didn't note it but I think it was 359 with pivot at R4C4.
Peter |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Tue Mar 17, 2009 5:49 pm Post subject: |
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Quote: | There are alternate paths to the prize, such as a swordfish. |
there two swordfish in the puzzle.
only one will solve it in one step
Code: | .---------------------.---------------------.---------------------.
| 7 56 8 | 9 56 4 | 13 13 2 |
| 3 569 59 | 15 156 2 | 8 7 4 |
| 2 4 1 | 8 3 7 | 5 6 9 |
:---------------------+---------------------+---------------------:
|W59 28 47 | 35 259 1 | 369 34589 3678 |
| 6 W59 3 | 4 7 8 | 2 W59 1 |
| 1 28 47 | 6 25 E39 |E39 458 78 |
:---------------------+---------------------+---------------------:
| 4 1 69 | 2 8 5 | 7 39 36 |
|W59 7 2569 | 13 4 3-9 | 169 1289 68 |
| 8 3 29 | 7 19 6 | 4 129 5 |
'---------------------'---------------------'---------------------' |
one of the swordfish has a corresponding extended w-wing on {5,9}
the w-wing is marked with a W
the extension with a E
eliminates the 9 in r8c6 |
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crunched
Joined: 05 Feb 2008 Posts: 168
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Posted: Wed Mar 18, 2009 12:59 am Post subject: |
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The 25-59-259 xyz (see boxes 4 & 5) does it all. It takes out the 5 in r4c4, leaving a 3, and the puzzle unravels.
Code: |
+---------------+-----------+-------------------+
| 7 56 8 | 9 56 4 | 13 13 2 |
| 359 3569 569 | 15 156 2 | 8 7 4 |
| 2 4 1 | 8 3 7 | 5 6 9 |
+---------------+-----------+-------------------+
| 59 28 47 | 35 259 1 | 369 34589 35678 |
| 6 59 3 | 4 7 8 | 2 59 1 |
| 1 28 47 | 6 25 39 | 39 34589 3578 |
+---------------+-----------+-------------------+
| 4 1 69 | 2 8 5 | 7 39 36 |
| 359 7 2569 | 13 4 39 | 1369 123589 3568 |
| 8 359 259 | 7 19 6 | 4 12359 35 |
+---------------+-----------+-------------------+
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Play this puzzle online at the Daily Sudoku site |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Wed Mar 18, 2009 7:56 am Post subject: disappearing UR |
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Cheshire Cat Sudoku *): the vanishing rectangle.
I solved this one in a curious **) way.
About halfway into the puzzle (and with only some PMs filled in) I noticed a UR type 1 (39) in r68c67, which meant that r8c7 could not be 3 or 9.
I wrote down this information "for later".
When I was done with basics, the cell r8c7 had lost the candidate 3: the UR had disappeared.
But the elimination is still valid! So, taking out 9 from r8c7, I had 9 confined to col 7 in box 6 and thus r5c8=5. Singles/basics from there.
I usually don't use UR eliminations until lesser means like basics or obvious wings have worked their voodoo, but it makes sense to write down any eliminations, because the UR just might disappear ...
----
*) "How do you know I'm mad?" said nataraj.
"You must be," said the Sudoku, "otherwise you wouldn't have come here."
**) “Curiouser and curiouser!” Cried nataraj (he was so much surprised, that for the moment he quite forgot how to speak good English). |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Wed Mar 18, 2009 5:46 pm Post subject: |
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the UR I mentioned is NOT VALID !
A valid UR should not extend to four boxes
I must have been mad (the tea I had for breakfast ???)
(I still like the story: sometimes URs - REAL URs - do disappear)
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DennyOR
Joined: 12 Sep 2007 Posts: 33 Location: Portland, Oregon
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Posted: Wed Mar 18, 2009 7:42 pm Post subject: |
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And the 91-13-35-59 chain takes out the same 9 as the xy-wing. |
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