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Does this one really need an 8-link xy-chain?

 
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Tue Jun 17, 2008 4:44 pm    Post subject: Does this one really need an 8-link xy-chain? Reply with quote

This puzzle from today's local paper is really hard.

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

play online

Usually their puzzles are rather tame, but with this one, the best I could do was this:
(after coloring on 4 and a kite on 9)

Code:

+--------------------------+--------------------------+--------------------------+
| 5       17      17#      | 2       49#     6        | 8       49#     3        |
| 38      4       9        | 3578    37      357      | 6       2       1        |
| 238     68      26       | 389     1       349      | 5       7       49       |
+--------------------------+--------------------------+--------------------------+
| 1       57      27*      | 356    -234    -235      | 9       46      8        |
| 6       9       4        | 17      8       17       | 3       5       2        |
|-28      58      3        | 569     29*     2459     | 7       1       46       |
+--------------------------+--------------------------+--------------------------+
| 7       23      8        | 139     6       1239     | 4       39#     5        |
| 4       236     5        | 379     237     2379     | 1       8       69       |
| 9       136     16#      | 4       5       8        | 2       36#     7        |
+--------------------------+--------------------------+--------------------------+

play online

... to use a long xy-chain (from 27 in r4c3 via column 3 and column 8 into col 5 to 29 in r6c5.

I checked it once more but have no better idea. URs anyone?
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Tue Jun 17, 2008 10:22 pm    Post subject: Reply with quote

There is a 38 UR at r23c14: <3> can be removed from r2c4 due to the strong links. But, it isn't helpful. I can't find anything better than your XY Chain.

Not simpler, but sort of interesting: if you Medusa color one cluster based in the right tower and another based in the left tower, a multi-color wrap results. (One color of the left cluster sees both colors of the other cluster.) But, the result is exactly the same as the XY Chain.
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Tue Jun 17, 2008 10:30 pm    Post subject: Reply with quote

There are shorter chains that attack <2> (4 links) and then <5> (6 links) in R6C6. Not very helpful.

Maybe you should get a different newspaper?

Keith Wink

By the way, the puzzle is not quite symmetric. If you make it so, by putting <4> in R5C3, that does not help to make it easier, except in the initial steps.
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Wed Jun 18, 2008 5:10 am    Post subject: Reply with quote

keith wrote:
Maybe you should get a different newspaper?





that would be very drastic. No, I don't think so. It's been only a few weeks that they introduced the advanced level and they probably still struggle to get it just right.

I actually quite like not knowing which solution methods will do the trick...

Thanks everybody for taking the time to look into this one!
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