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Freep / LA Times Nov 2

 
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
PostPosted: Fri Nov 02, 2007 2:46 pm    Post subject: Freep / LA Times Nov 2 Reply with quote
This should be freep's of today, I copied it from the LA Times. Hope this saves keith ...
keith wrote:
But time is tight for me during the week

...a little effort:
Code:

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

002107300080200010000090000018305760000000000073602940000020000030006070009701800
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re'born



Joined: 28 Oct 2007
Posts: 80
PostPosted: Fri Nov 02, 2007 3:46 pm    Post subject: Reply with quote
ooh, this is a fun one. It seems the obvious solution is to find the 2 x-wings and then apply an xy-wing. But I prefer to look for moves which annihilate the puzzle instantly. So I thought, hey, this is a BUG+4 grid
Code:
.---------------.---------------.---------------.
| 4    9    2   | 1    56   7   | 3    8    56  |
| 7    8    56  | 2    36+5 34  | 45+6 1    9   |
| 3    56   1   | 45   9    8   | 46+5 2    7   |
:---------------+---------------+---------------:
| 9    1    8   | 3    4    5   | 7    6    2   |
| 26   24   46  | 8    7    9   | 15   35   13  |
| 5    7    3   | 6    1    2   | 9    4    8   |
:---------------+---------------+---------------:
| 8    56   7   | 45   2    34  | 16+5 9    13  |
| 1    3    45  | 9    8    6   | 2    7    45  |
| 26   24   9   | 7    35   1   | 8    35   46  |
'---------------'---------------'---------------'

which implies r2c7 <> 5. But sadly this doesn't crack the puppy (it still needs one of the x-wings) and I can't see a further way to exploit it.
So I dipped back into my bag of tricks and pulled out xyz-transport.
Code:
.---------------.---------------.---------------.
| 4    9    2   | 1    56-  7   | 3    8    56A |
| 7    8    56  | 2    356  34  | 456a 1    9   |
| 3    56   1   | 45B  9    8   | 456a-2    7   |
:---------------+---------------+---------------:
| 9    1    8   | 3    4    5   | 7    6    2   |
| 26   24   46  | 8    7    9   | 15*  35   13  |
| 5    7    3   | 6    1    2   | 9    4    8   |
:---------------+---------------+---------------:
| 8    56*  7   | 45b  2    34  | 156* 9    13  |
| 1    3    45  | 9    8    6   | 2    7    45  |
| 26   24   9   | 7    35   1   | 8    35   46  |
'---------------'---------------'---------------'

There is an xyz-wing in r7c2, r57c7 that implies one of the three cells is a 5. We transport the 5's in r57c7 to r1c9 via r23c7 and the 5 in r7c2 to r3c4 via r7c4. So now r1c9 or r3c4 is a 5 and hence r1c5, r3c7 <> 5, solving the puzzle.
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
PostPosted: Fri Nov 02, 2007 4:09 pm    Post subject: Reply with quote
far as I remember, basic methods got me clear to a BUG+2 (5 in r2c5 or 6 somewhere in box 3). Can't re-create immediately but will try.

oops, sorry. I see a xwing 5 in c24 on my sheet. Not quite basic.
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Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS
PostPosted: Fri Nov 02, 2007 5:16 pm    Post subject: LA Nov 2 Reply with quote
An x-wing in 6, an x-wing in 5, and a skyscraper in 5 and the rest was singles.

Earl
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
PostPosted: Sat Nov 03, 2007 5:38 am    Post subject: Reply with quote
I also used Earl's X-Wing and Skyscraper.

However, instead of the Skyscraper, there is a {56} UR in C27 that removes <5> from R37C7 followed by an XY Wing with pivot at R3C7 to eliminate another <5> and solve the puzzle.
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Sat Nov 03, 2007 9:42 pm    Post subject: Reply with quote
In re'born's grid the x-wing on <6> takes out <6> in the cell marked a. Then, the BUG+3 takes out <5> in the same cell. (One of the 3-candidate cells must be <5>.)

Keith
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