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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Fri Feb 20, 2009 11:01 pm Post subject: MM 1321 2/20/09 |
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Code: |
+-------+-------+-------+
| 3 . . | . . 6 | . 2 . |
| . . . | . 2 . | . . . |
| . . . | . . 8 | . 5 1 |
+-------+-------+-------+
| . . 1 | . . 5 | 8 4 . |
| . 4 . | . . . | . 9 . |
| . 9 8 | 1 . . | 2 . . |
+-------+-------+-------+
| 8 1 . | 6 . . | . . 3 |
| . . . | . 5 . | . . . |
| . 5 . | 8 . 7 | . . 9 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Sat Feb 21, 2009 10:20 pm Post subject: |
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I did not find may choices, but then a one-step solution.
Quote: | A w-wing<37> in r3c5 & r8c3 with strong ling on <3> in box<8> did not provide any eliminations, but transporting the <7> from r8c3 to r5c4 via r5c3 breaks it open.
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Ted |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Fri Feb 27, 2009 5:42 am Post subject: |
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I played the Type 2 UR on 56. Then a W-Wing on 79 eliminated a candidate, followed by a pincer transport which finished it. |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Fri Feb 27, 2009 7:21 am Post subject: |
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Code: | after basics: a DP and an M-Wing
+--------------------------------------------------------------+
| 3 78 45+9 | 457 1 6 | 79 2 48 |
| 1 78 45 | 457+3 2 9 | 37 6 48 |
| 49 2 6 | d347 e37 8 | 39-7 5 1 |
|--------------------+--------------------+--------------------|
| 267 3 1 | 279 679 5 | 8 4 67 |
| 56 4 b27 | c27 8 3 | 1 9 56 |
| 567 9 8 | 1 67 4 | 2 3 567 |
|--------------------+--------------------+--------------------|
| 8 1 49 | 6 49 2 | 5 7 3 |
| 79 6 a37 | 9-3 5 1 | 4 8 2 |
| 24 5 2-3 | 8 f34 7 | 6 1 9 |
+--------------------------------------------------------------+
# 44 eliminations remain
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Skip these UR eliminations.
Code: | r6 UR Type 2 [r56c19] in <56> <> 7 [r6c5]
UR [r12c34] in <45> <> 4 [r1c4]
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I believe there is a <4578> DP in [r12c2349]. If so, then one of the following statements must be true.
Code: | (9)r1c3 - (9=7)r1c7 - (7)r3c7
(3)r2c4 - (3=7)r2c7 - (7)r3c7
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This now opens up a (generalized) M-Wing elimination that cracks the puzzle.
Code: | Eureka PPB
(3=7)r8c3 - (7)r5c3 = (7)r5c4 - (7)r3c4 = (7-3)r3c5 = (3)r9c5 => [r8c4],[r9c3]<>3
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Ping Pong Balls (PPB): An AIC that starts and ends with a strong inference. (Courtesy of a suggestion by storm_norm!) |
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Steve R
Joined: 24 Oct 2005 Posts: 289 Location: Birmingham, England
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Posted: Sat Feb 28, 2009 1:43 pm Post subject: |
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The grid is riddled with a bewildering number of deadly patterns so it’s easy to miss the most helpful.
To avoid a (567) in r456c19, 2 must be placed in r4c1 and singles follow.
Steve |
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