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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Mon Mar 07, 2011 7:45 am Post subject: Daily Sudoku Competition for Mar 6, 2011 |
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009600014003080200006001000100700006000010000500002007000900300000050000940003500
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+-------+-------+-------+
| . . 9 | 6 . . | . 1 4 |
| . . 3 | . 8 . | 2 . . |
| . . 6 | . . 1 | . . . |
+-------+-------+-------+
| 1 . . | 7 . . | . . 6 |
| . . . | . 1 . | . . . |
| 5 . . | . . 2 | . . 7 |
+-------+-------+-------+
| . . . | 9 . . | 3 . . |
| . . . | . 5 . | . . . |
| 9 4 . | . . 3 | 5 . . |
+-------+-------+-------+
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Mon Mar 07, 2011 10:45 pm Post subject: |
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I found 3 steps:
Quote: | [1] 578XYW; r4c7<>8
[2] 128DP r89c349; r8c9=9
[3] 18URr89c34[(8)r4c3=(8)r56c4]; r4c6<>8 |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Tue Mar 08, 2011 2:30 pm Post subject: |
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I used 5 steps........
Quote: | xy-wing (57-8) vertex (57)r1c6; r4c7<>8
ANP(58=2)r13c2-(5)r1c2=r1c6-(5=8)r4c6; r4c2<>8
(2=8)r1c1-(8=5)r3c2-r3c4=r1c6-(5=8)r4c6-(8=2)r4c3; r5c1<>2
xy-wing (-238)vertex (38)r5c1; r1c2<>2
ANP(48=7)r78c6-(4)r8c6=r8c8-(4=8)r7c8-r6c8=(8)r6c4; r4c6<>8
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Ted |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Tue Mar 08, 2011 2:51 pm Post subject: |
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Asellus,
I also looked at the ADP(128) in r89c349. I considered it as 6-cells either (18)r89c3|(12)r89c4|(28)r89c9 or (12)r89c3|(18)r89c4|(28)r89c9 using both internal and external inferences, but was not able to make any conclusions.
I also wondered if the pattern was like a Type 1 MUG which would directly set r8c9=9, but I am still unsure of the rules that define a MUG.
Would you please elaborate on your logic?
Ted |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Tue Mar 08, 2011 2:54 pm Post subject: |
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I kept half-expecting wapati to come along and jump on this puzzle. Since he's off somewhere else, I'll provide a solution for him.
Code: | after basics, XY-Wing, and more basics:
+--------------------------------------------------------------+
| *28 *258 9 | 6 3 57 | 78 1 4 |
| 7 1 3 | 4 8 9 | 2 6 5 |
| 4 58 6 | 25 27 1 | 78 39 39 |
|--------------------+--------------------+--------------------|
| 1 *238 #28 | 7 4 5-8 | 9 2358 6 |
| *238 9 7 | 358 1 6 | 4 2358 238 |
| 5 6 4 | #38 9 2 | 1 *38 7 |
|--------------------+--------------------+--------------------|
| 6 *278 5 | 9 27 *478 | 3 *248 1 |
| 238 2378 128 | 128 5 478 | 6 2489 289 |
| 9 4 128 | 128 6 3 | 5 7 28 |
+--------------------------------------------------------------+
# 57 eliminations remain
Sashimi Franken Jellyfish <> 8 r4c6
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Tue Mar 08, 2011 4:55 pm Post subject: |
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Ted wrote: | I also wondered if the pattern was like a Type 1 MUG which would directly set r8c9=9, but I am still unsure of the rules that define a MUG.
Would you please elaborate on your logic? |
Yes, it is a "Type 1" MUG. That <9> is the only digit that avoids the MUG deadly pattern. As for recognizing such patterns, I suggest reading Myth Jellies's post here. Some of the possible MUGs discussed there are beyond my ability to spot readily. However, the one here is easy. Start with the "3-digit 2-row 3-column 3-box" permeable MUG. Then, as Myth Jellies says, "any deadly pattern that you come up with when reducing a deadly pattern also qualifies as a deadly pattern." Here, the pattern is reduced by a <1> in b9. The pattern could be reduced by any or all of <1>, <2> and <8> distributed amongst the 3 boxes and it would still be deadly. |
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peterj
Joined: 26 Mar 2010 Posts: 974 Location: London, UK
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Posted: Tue Mar 08, 2011 5:17 pm Post subject: |
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Danny, great fish! There is no-way I would find something like that - unless perhaps it was also a grouped x-chain or stumbled on it when on one of my broken-wing excursions. I still find even a Swordfish something of a struggle |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Tue Mar 08, 2011 7:04 pm Post subject: |
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peterj wrote: | Danny, great fish! |
Yes. I wish that I could take credit for finding it w/o my solver. That's why I waited 1.5 days before posting the solution. I believe wapati loves to solve complicated fish patterns manually ... and I wanted to give him time to take credit for finding it.
Regards, Danny |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Fri Mar 11, 2011 5:35 am Post subject: |
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W-Wing (58) plus transport
Potential 18 DP in boxes 78, a 2 is needed to kill it, common outcome solves box 2 |
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