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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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 Posted: Sat Nov 12, 2011 8:44 pm Post subject: Free Press September 25, 2009 |
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Found this is in a folder. I believe I did not post it when it was fresh.
| Code: | Puzzle: FP092509
+-------+-------+-------+
| . . . | . 2 6 | . . 9 |
| . 5 . | . . . | . 2 . |
| . 6 1 | 9 . . | 7 . . |
+-------+-------+-------+
| 8 . . | . 1 . | . . . |
| . 7 . | 6 . 8 | . 5 . |
| . . . | . 9 . | . . 8 |
+-------+-------+-------+
| . . 7 | . . . | 2 3 . |
| . 2 . | . . . | . 1 . |
| 6 . 5 | 1 . . | . . . |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site
Keith
Last edited by keith on Sat Nov 12, 2011 10:00 pm; edited 1 time in total |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sat Nov 12, 2011 9:42 pm Post subject: |
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After basics: | Code: | +----------------+----------------+----------------+
| 7 #348 348 | 5 2 6 | 1 A48 9 |
| 49 5 489 |-47 478 1 | 6 2 3 |
| 2 6 1 | 9 D348 D34 | 7 C48 5 |
+----------------+----------------+----------------+
| 8 349 3469 | 347 1 5 | 349 67 2 |
| 349 7 2 | 6 34 8 | 349 5 1 |
| 5 1 346 | 2 9 347 | 34 67 8 |
+----------------+----------------+----------------+
| 1 #489 7 |B48 5 49 | 2 3 6 |
| 349 2 3489 | 3478 6 3479 | 5 1 47 |
| 6 34 5 | 1 347 2 | 8 9 47 |
+----------------+----------------+----------------+ |
Amazing.
AB are W-wing pincers on 4, the strong link is ##. If A is 4, C is not 4, one of D is 4, and R2C4 is not 4.
Puzzle solved.
Sudoku Susser says:
| Quote: | 7 x Comprehensive Forcing Chains
1 x XY-Wing
1 x Intersection Removal
1 x Simple Naked Sets
25 x Pinned Squares |
Keith
Last edited by keith on Sat Nov 12, 2011 9:58 pm; edited 1 time in total |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Sat Nov 12, 2011 9:57 pm Post subject: |
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| Code: | *-----------------------------------------------------------*
| 7 348 348 | 5 2 6 | 1 48 9 |
| 49 5 489 | 47 478 1 | 6 2 3 |
| 2 6 1 | 9 348 34 | 7 48 5 |
|-------------------+-------------------+-------------------|
| 8 49-3 469-3 |*347 1 5 | 349 67 2 |
|*349 7 2 | 6 34 8 | 349 5 1 |
| 5 1 346 | 2 9 347 | 34 67 8 |
|-------------------+-------------------+-------------------|
| 1 489 7 | 48 5 49 | 2 3 6 |
|*349 2 3489 |*3478 6 3479 | 5 1 47 |
| 6 34 5 | 1 347 2 | 8 9 47 |
*-----------------------------------------------------------*
Skyscraper3 => r4c23,r5c5<>3
*-----------------------------------------------------------*
| 7 348 348 | 5 2 6 | 1 48 9 |
|c49 5 489 |d47 x78 1 | 6 2 3 |
| 2 6 1 | 9 38 34 | 7 48 5 |
|-------------------+-------------------+-------------------|
| 8 49 469 | 37 1 5 | 349 67 2 |
| 39 7 2 | 6 4 8 | 39 5 1 |
| 5 1 346 | 2 9 37 | 34 67 8 |
|-------------------+-------------------+-------------------|
| 1 489 7 | 48 5 49 | 2 3 6 |
|b349 2 3489 | 348-7 6 349-7 | 5 1 a47 |
| 6 34 5 | 1 x37 2 | 8 9 4-7 |
*-----------------------------------------------------------*
w-wing extended
(7=4)r8c9-(4)r8c1=(4)r2c1-(4=7)r2c4...-(7)r2c5=(7)r9c5 => r8c46,r9c9<>7 |
Last edited by arkietech on Sat Nov 12, 2011 11:48 pm; edited 1 time in total |
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SudoQ
Joined: 02 Aug 2011
Posts: 127
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| Posted: Sat Nov 12, 2011 10:51 pm Post subject: |
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It can also be solved like this:
| Code: | r8c3/4=8:
r8c3=8 -> r2c3<>8 -> r2c5<>7
r8c4=8 -> r7c4=4
=> r2c4<>4 |
/SudoQ |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Sat Nov 12, 2011 11:47 pm Post subject: |
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| I used a Skyscraper on 3 and XY-Wings on 347 and 493 before I got to the W-Wing on 48. |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Sun Nov 13, 2011 10:03 am Post subject: |
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| keith wrote: |
Amazing.
AB are W-wing pincers on 4, the strong link is ##. If A is 4, C is not 4, one of D is 4, and R2C4 is not 4.
Puzzle solved.
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Nice Find Keith!  | Code: | *-----------------------------------------------------------*
| 7 b348 348 | 5 2 6 | 1 a48 9 |
| 49 5 489 | 7-4 478 1 | 6 2 3 |
| 2 6 1 | 9 x348 x34 | 7 x48 5 |
|-------------------+-------------------+-------------------|
| 8 349 3469 | 347 1 5 | 349 67 2 |
| 349 7 2 | 6 34 8 | 349 5 1 |
| 5 1 346 | 2 9 347 | 34 67 8 |
|-------------------+-------------------+-------------------|
| 1 c489 7 |d48 5 49 | 2 3 6 |
| 349 2 3489 | 3478 6 3479 | 5 1 47 |
| 6 34 5 | 1 347 2 | 8 9 47 |
*-----------------------------------------------------------*
w-wing extended
(4)r3c56=(4)r3c8-...(4=8)r1c8-(8)r1c2=(8)r7c2-(8=4)r7c4 => r2c4<>4 |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Sun Nov 13, 2011 3:32 pm Post subject: |
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Another technique that results in r2c4<>4 is the "almost naked pair" in r2c13
anp(49=8)r2c13-(8)r8c3=(8)r8c4-(8=4)r7c4; r2c4<>4
If r1c3<>8, then naked pair (49)r2c13; r2c4<>4
If r1c3=8, then r8c3<>8, then r8c4=8, then r7c4=4; r2c4<>4
Ted |
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