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Puzzle 11/05/30: B Advanced

 
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Mon May 30, 2011 2:23 am    Post subject: Puzzle 11/05/30: B Advanced Reply with quote

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

Play this puzzle online at the Daily Sudoku site
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Marty R.



Joined: 12 Feb 2006
Posts: 5178
Location: Rochester, NY, USA

PostPosted: Wed Jun 01, 2011 4:54 am    Post subject: Reply with quote

Too many moves for this classification of puzzle.

Multi-coloring; r1c2<>9
XYZ-Wing (249); r2c6<>9
Coloring; r5c2, r7c1<>7
W-Wing (49); r3c3<>4
XY-Wing (174), flightless with transport; r5c2<>4
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Wed Jun 01, 2011 5:34 am    Post subject: Reply with quote

Marty,

Code:
 after basics
 +-----------------------------------------------------------------------+
 |  6      149    249    |  14     249    8      |  37     5      37     |
 |  12479  3      2479   |  5      249    149    |  8      49     6      |
 |  459    8      459    |  3      6      7      |  49     2      1      |
 |-----------------------+-----------------------+-----------------------|
 |  47     5      1      |  8      479    2      |  6      3      49     |
 |  479    479    6      |  47     1      3      |  5      8      2      |
 |  8      2      3      |  6      5      49     |  1      7      49     |
 |-----------------------+-----------------------+-----------------------|
 |  1479   6      479    |  2      3      5      |  479    149    8      |
 |  3      147    8      |  9      47     6      |  2      14     5      |
 |  25     479    25     |  147    8      14     |  3479   6      37     |
 +-----------------------------------------------------------------------+
 # 61 eliminations remain

Single-stepper(s):

Code:
 L-Wing: (1)r9c4 = r1c4 - r1c2 = (1-7)r8c2 = (7)r8c5  =>  r9c4<>7
 L-Wing: (1)r8c2 = r1c2 - r1c4 = (1-7)r9c4 = (7)r8c5  =>  r8c2<>7

 W-Wing: (4=1)r8c8 - r8c2 = r1c2 - r2c1 = r2c6 - (1=4)r9c6  =>  r8c5,r9c7<>4

Otherwise:

Code:
 r19c79  <37> UR Type 1.2224             <> 37   r9c7

 c38\r27 Sashimi X-Wing                  <> 9    r2c1   extraneous
 r39\c27 Sashimi X-Wing                  <> 9    r1c2

 c37r3   Skyscraper                      <> 4    r7c8,r9c2

 <49+7>  XY-Wing  r5c2/r5c4+r9c2         <> 7    r9c4

Note: the UR Type 1 cleans up a lot of "real estate" through additional basics.

Regards, Danny



AND ... I've been waiting for an opportunity to make a statement like this:

The W-Wing can be viewed as a flightless 2-String Kite with pincer extensions. _ Laughing _
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Marty R.



Joined: 12 Feb 2006
Posts: 5178
Location: Rochester, NY, USA

PostPosted: Wed Jun 01, 2011 4:50 pm    Post subject: Reply with quote

Seeing as we have different ideas of what a Kite is, I'd call the two-string kite with extensions Simple Coloring.

As to the 14 W-Wing, I can see that the two 14 cells are linked by three strong links, although my three SLs have different cells than what I see in your notation, which I don't understand.
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Wed Jun 01, 2011 5:34 pm    Post subject: Reply with quote

Marty R. wrote:
Seeing as we have different ideas of what a Kite is, I'd call the two-string kite with extensions Simple Coloring.

As to the 14 W-Wing, I can see that the two 14 cells are linked by three strong links, although my three SLs have different cells than what I see in your notation, which I don't understand.

Code:
+-----------------------------------+
|  .  1  .  |  1  .  .  |  .  .  .  |
|  1  /  /  |  /  /  1  |  /  /  /  |
|  .  /  .  |  .  .  .  |  .  .  1  |
|-----------+-----------+-----------|
|  .  /  1  |  .  .  .  |  .  .  .  |
|  .  /  .  |  .  1  .  |  .  .  .  |
|  .  /  .  |  .  .  .  |  1  .  .  |
|-----------+-----------+-----------|
|  1  /  .  |  .  .  .  |  .  1  .  |
|  .  1  .  |  .  .  .  |  .  14 .  |
|  .  /  .  |  1  .  14 |  .  .  .  |
+-----------------------------------+

Whether you call it a Kite or a 2-String Kite (as I learned), there is a strong link on <1> in [r2] and [c2]. This would normally perform the elimination r8c6<>1, but <1> doesn't exist in r8c6. (Yes, there also happens to be a strong link on <1> in [b1], but that isn't of any consequence to the logic.)

Logic: pincer extensions on 2-String Kite -- strong links enclosed in parentheses ()

Code:
(r8c8<>4 r8c8=1) (r8c2<>1 r1c2=1) (r2c1<>1 r2c6=1) (r9c6<>1 r9c6=4)

                 | ------- 2-String Kite ------- |

Any cell that sees r8c8 and r9c6 can have <4> elminated.

Regards, Danny
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Marty R.



Joined: 12 Feb 2006
Posts: 5178
Location: Rochester, NY, USA

PostPosted: Wed Jun 01, 2011 7:15 pm    Post subject: Reply with quote

Quote:
Whether you call it a Kite or a 2-String Kite

I don't call it either. I learned Kites as a perpendicular version of Skyscrapers which are weakly linked.

My Simple Coloring chain on 1 is:

R8c8, true
R8c2, false
R1c2, true
R1c4, false
R9c4, true
R9c6, false

My personal opinion is that if a move can be described with multiple techniques, then the simplest one should be used, which, in this case, is Simple Coloring in my humble opinion.

Cheers.
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