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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Wed Feb 17, 2010 6:22 pm Post subject: Puzzle 10/02/17 (A) |
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Code: | +-----------------------+
| 3 . . | . . . | 5 . . |
| . 1 . | 6 5 . | . . . |
| . . 5 | . . . | . . . |
|-------+-------+-------|
| . 4 . | . 6 . | . . 5 |
| . 2 . | 3 8 . | 7 4 . |
| . . . | . . 5 | . 1 . |
|-------+-------+-------|
| 2 . . | . 1 . | 8 7 . |
| . . . | . 4 3 | 2 6 1 |
| . . . | 2 . . | . 5 3 |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Thu Feb 18, 2010 5:44 am Post subject: |
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My typical hodgepodge of moves, including an XY-Chain, ER, XY, X and XY. |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Thu Feb 18, 2010 3:44 pm Post subject: |
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I fell into a three step solution.
Quote: | ER on 8 with hinge in box1 and strong link in row9, which sets up a
xy-wing 78-9 with vertex 78 in r2c9,
a Type 1 UR 78 in r68c13 completes the puzzle.
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Ted |
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Wendy W
Joined: 04 Feb 2008 Posts: 144
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Posted: Fri Feb 19, 2010 1:13 am Post subject: |
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I went the chain route with a skyscraper and an XY wing along the way. I was really looking for a way to use all those 789 triples but couldn't find one. |
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oaxen
Joined: 10 Jul 2006 Posts: 96
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Posted: Fri Feb 19, 2010 9:44 am Post subject: Two stepper |
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Congratulations Danny!
This was a puzzle that even for a solver with the simplified Oaxen-thread method needed two steps. Like Wendy says, there were a lot of 789 who eventually blocked the first chain.
Lars |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Sat Feb 20, 2010 3:24 am Post subject: |
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Wendy W wrote: | I went the chain route with a skyscraper and an XY wing along the way. I was really looking for a way to use all those 789 triples but couldn't find one. |
one way is to use them in a ALS stucture.
Code: | +--------------------+----------------+-------------+
| 3 (789) 4 | 1 29 2789 | 5 89 6 |
| 78(9) 1 2 | 6 5 78(9) | 4 3 78 |
| 6 (789) 5 | 789 3 4 | 1 289 278 |
+--------------------+----------------+-------------+
| 1 4 89 | 79 6 279 | 3 28 5 |
| 5 2 6 | 3 8 1 | 7 4 9 |
| 789 3789 3789 | 4 29 5 | 6 1 28 |
+--------------------+----------------+-------------+
| 2 3569 39 | 59 1 (69) | 8 7 4 |
| 789 5789 789 | 589 4 3 | 2 6 1 |
| 4 -8(6) 1 | 2 7 8(6) | 9 5 3 |
+--------------------+----------------+-------------+ |
notice that if the 9's in the 789 triples in r13c2 are false, then the 78 naked pair is left. this naked pair would eliminate the 8 in r9c2.
if the 9's are true, then...
(9)r13c2 - (9)r2c1 = (9)r2c6 - (9=6)r7c6 - (6)r9c6 = (6)r9c2
6 is true in r9c2
either way, 8 is false in r9c2. 6 can be placed. |
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Wendy W
Joined: 04 Feb 2008 Posts: 144
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Posted: Sat Feb 20, 2010 10:41 pm Post subject: |
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Wow, Norm, that's really clever! Thank you. |
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