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Pattern Game 1/27/12 by dobrichev

 
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sat Jan 28, 2012 10:57 pm    Post subject: Pattern Game 1/27/12 by dobrichev Reply with quote

by dobrichev » Fri Jan 27, 2012 ED=6.0
Code:
 *-----------*
 |.92|...|..4|
 |7.4|...|...|
 |56.|1..|...|
 |---+---+---|
 |..1|.8.|...|
 |...|9.6|...|
 |...|53.|6..|
 |---+---+---|
 |...|..4|.62|
 |...|...|1.3|
 |8..|...|59.|
 *-----------*
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun Jan 29, 2012 2:47 am    Post subject: Reply with quote

I was at a brick wall until I spotted a quad in c8 which had eluded me. An XYZ-Wing (237); r4c7<>7 reduced the grid to a BUG+3. The three BUG killers were 3-7-9. The 37 formed a pseudo cell which forced a 9 in the same row as the killer 9; r3c9<>9.
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JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium

PostPosted: Sun Jan 29, 2012 11:24 am    Post subject: Reply with quote

Code:
+----------+-----------------+--------------+
| 1  9   2 | 68  (67)  378   | 37   5    4  |
| 7  8   4 | 23  2(5)  3(59) | 39   1    6  |
| 5  6   3 | 1   4     -7(9) | 279  278  89 |
+----------+-----------------+--------------+
| 6  35  1 | 4   8     27    | 279  237  59 |
| 2  35  8 | 9   17    6     | 4    37   15 |
| 4  7   9 | 5   3     12    | 6    28   18 |
+----------+-----------------+--------------+
| 3  1   5 | 7   9     4     | 8    6    2  |
| 9  2   7 | 68  (56)  58    | 1    4    3  |
| 8  4   6 | 23  12    13    | 5    9    7  |
+----------+-----------------+--------------+

9r3c6=(9-5)r2c6=5r2c5-(5=6)r8c5-(6=7)r1c5 => -7r3c6
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sun Jan 29, 2012 11:50 am    Post subject: Reply with quote

Code:
 *--------------------------------------------------*
 | 1    9    2    | 68   67   378  | 37   5    4    |
 | 7    8    4    |d23   25   359  |c39   1    6    |
 | 5    6    3    | 1    4    79   | 279  278 b89   |
 |----------------+----------------+----------------|
 | 6    35   1    | 4    8    27   | 279  237  59   |
 | 2    35   8    | 9    17   6    | 4    37   15   |
 | 4    7    9    | 5    3    2-1  | 6    28  a18   |
 |----------------+----------------+----------------|
 | 3    1    5    | 7    9    4    | 8    6    2    |
 | 9    2    7    | 68   56   58   | 1    4    3    |
 | 8    4    6    |e23   12  f13   | 5    9    7    |
 *--------------------------------------------------*
xy chain
(1=8)r6c9-(8=9)r3c9-(9=3)r2c7-(3=2)r2c4-(2=3)r9c4-(3=1)r9c6 => r6c6<>1
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sun Jan 29, 2012 4:22 pm    Post subject: Reply with quote

A busy puzzle.

Code:
 +-----------------------+
 | . 9 2 | . . . | . . 4 |
 | 7 . 4 | . . . | . . . |
 | 5 6 . | 1 . . | . . . |
 |-------+-------+-------|
 | . . 1 | . 8 . | . . . |
 | . . . | 9 . 6 | . . . |
 | . . . | 5 3 . | 6 . . |
 |-------+-------+-------|
 | . . . | . . 4 | . 6 2 |
 | . . . | . . . | 1 . 3 |
 | 8 . . | . . . | 5 9 . |
 +-----------------------+

   c8b3  Locked Candidate 1              <> 1    r56c8
 r7  b7  Locked Candidate 1              <> 1    r7c5
 r8  b7  Locked Candidate 1              <> 2    r8c456
   c8b3  Locked Candidate 1              <> 5    r45c8

   c8    Naked  Quad                     <> 2378 r12c8

 r3  b3  Locked Candidate 1              <> 8    r3c36

   c4    Naked  Pair                     <> 23   r1c4

   c6b5  Locked Candidate 1              <> 2    r239c6
   c7b3  Locked Candidate 1              <> 3    r4c7

 r2  b2  Locked Candidate 1              <> 2    r2c7

 <23+7>  XYZ-Wing r4c8/r4c6+r5c8         <> 7    r4c7

   c8b6  Locked Candidate 1              <> 7    r3c8

   c8    Naked  Pair                     <> 28   r4c8

 <27+9>  XY-Wing  r4c6/r3c6+r4c7         <> 9    r3c7

 +-----------------------------------------------------+
 |  1    9    2    |  68   67   378  |  37   5    4    |
 |  7    8    4    |  23   25   359  |  39   1    6    |
 |  5    6    3    |  1    4    79   |  27   28   89   |
 |-----------------+-----------------+-----------------|
 |  6    35   1    |  4    8    27   |  29   37   59   |
 |  2    35   8    |  9    17   6    |  4    37   15   |
 |  4    7    9    |  5    3    12   |  6    28   18   |
 |-----------------+-----------------+-----------------|
 |  3    1    5    |  7    9    4    |  8    6    2    |
 |  9    2    7    |  68   56   58   |  1    4    3    |
 |  8    4    6    |  23   12   13   |  5    9    7    |
 +-----------------------------------------------------+
 # 32 eliminations remain

If r1c6<>7 and r2c6<>3, then a BUG remains. This is unacceptable. So, at least one of r1c6=7 and/or r2c6=3 must be true. Either way, r1c6<>3 follows.
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Sun Jan 29, 2012 7:22 pm    Post subject: Reply with quote

Initially I found a couple of xy-chains such as:

(9=7)r3c6-(7=6=5=2)r182c5-(2=3=9)r2c47; r2c6<>9

But then I tried the brute force approach; a BUG+6
BUG+6 => r1c7=3

(7)r1c6-(7=3)r1c7
(3)r2c6-r1c6=(3)r1c7
(7)r3c78-(7=3)r1c7
(7)r4c78-(7=2=1=3)r469c6-r1c6=(3)r1c7

Ted
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Sun Jan 29, 2012 8:07 pm    Post subject: Reply with quote

tlanglet wrote:
I tried the brute force approach; a BUG+6
BUG+6 => r1c7=3

(7)r1c6-(7=3)r1c7
(3)r2c6-r1c6=(3)r1c7
(7)r3c78-(7=3)r1c7
(7)r4c78-(7=2=1=3)r469c6-r1c6=(3)r1c7

Code:
 after basics
 +-----------------------------------------------------+
 |  1    9    2    |  68   67   378  |  37   5    4    |
 |  7    8    4    |  23   25   359  |  39   1    6    |
 |  5    6    3    |  1    4    79   |  279  278  89   |
 |-----------------+-----------------+-----------------|
 |  6    35   1    |  4    8    27   |  279  237  59   |
 |  2    35   8    |  9    17   6    |  4    37   15   |
 |  4    7    9    |  5    3    12   |  6    28   18   |
 |-----------------+-----------------+-----------------|
 |  3    1    5    |  7    9    4    |  8    6    2    |
 |  9    2    7    |  68   56   58   |  1    4    3    |
 |  8    4    6    |  23   12   13   |  5    9    7    |
 +-----------------------------------------------------+

Hmmm!!! If you eliminate your candidates -- r2c6<>3 and r1c6,r34c78<>7 -- then you have what appears to be a BUG because all of the unsolved cells are bivalues. However, there is a second constraint that's also necessary -- no Singles present when reduced to bivalue cells.

Code:
 Ted's grid after: r2c6<>3 and r1c6,r34c78<>7
 +-----------------------------------------------------+
 |  1    9    2    |  68   67   38   |  37   5    4    |
 |  7    8    4    |  23   25   59   |  39   1    6    |
 |  5    6    3    |  1    4    79   |  29   28   89   |
 |-----------------+-----------------+-----------------|
 |  6    35   1    |  4    8    27   |  29   23   59   |
 |  2    35   8    |  9    17   6    |  4    37   15   |
 |  4    7    9    |  5    3    12   |  6    28   18   |
 |-----------------+-----------------+-----------------|
 |  3    1    5    |  7    9    4    |  8    6    2    |
 |  9    2    7    |  68   56   58   |  1    4    3    |
 |  8    4    6    |  23   12   13   |  5    9    7    |
 +-----------------------------------------------------+

 Hidden Single: r1c7=7   in [b3]
 Hidden Single: r5c8=7   in [b6]
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun Jan 29, 2012 8:38 pm    Post subject: Reply with quote

Quote:
If r1c6<>7 and r2c6<>3, then a BUG remains. This is unacceptable. So, at least one of r1c6=7 and/or r2c6=3 must be true. Either way, r1c6<>3 follows.

Danny, same result, but, alternatively, the 37 is a pseudo cell that is part of a 1237 quad in c6; r3c6<>7.
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Clement



Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania

PostPosted: Mon Jan 30, 2012 11:49 pm    Post subject: Pattern Game 1/27/12 by dobrichev Reply with quote

The xyz-Wing 237 mentioned by Marty ealier opens an XY-Wing 279 pivoted in r4c6; r3c7<>9 reduces the Grid to BUG+2. Either r1c6=7 or r2c6=3.
If r1c6=7; r2c7=9
If r2c6=3; r2c7=9;r2c7<>3.
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