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Victor



Joined: 29 Sep 2005
Posts: 207
Location: NI

PostPosted: Mon Apr 28, 2008 10:10 am    Post subject: SFX Reply with quote

These days when I go on trips I run off a few puzzles for use in spare minutes, instead of the paperbacks that used to accompany me. I haven't solved them all this time, but managed to do this (non-trivial) one, M3981695 (32).
Code:

+---------------------+--------------+----------------+
| 5      2389  1289   | 7    18 29   | 6  2349  349   |
| 16     29    4      | 15   3  156  | 8  29    7     |
| 7      2389  2689   | 29   68 4    | 1  5     39    |
+---------------------+--------------+----------------+
| 3      1     7      | 25   4  25   | 9  8     6     |
| 48     6     58     | 13   9  13   | 45 7     2     |
| 249    2459  259    | 6    7  8    | 3  14    145   |
+---------------------+--------------+----------------+
| 124689 24589 125689 | 1349 16 1369 | 7  13469 13459 |
| 1469   7     3      | 8    5  169  | 2  1469  149   |
| 1469   459   1569   | 1349 2  7    | 45 13469 8     |
+---------------------+--------------+----------------+

Play this puzzle online
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Mon Apr 28, 2008 11:41 am    Post subject: Reply with quote

Nice,

finned x-wing (grouped skyscraper), xy-wing, a couple of kite/skyscrapers, and a M-wing for both numbers (not in this order).
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Asellus



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

PostPosted: Mon Apr 28, 2008 10:39 pm    Post subject: Reply with quote

There's a nice Sashimi Swordfish right at the start that eliminates <4> in r5c1 and moves things along.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Mon Apr 28, 2008 11:11 pm    Post subject: Reply with quote

Code:
.---------------------.---------------------.---------------------.
| 5      2389   1289  | 7      18     29    | 6      2349   349   |
| 16     29     4     | 15     3      156   | 8      29     7     |
| 7      2389   2689  | 29     68     4     | 1      5      39    |
:---------------------+---------------------+---------------------:
| 3      1      7     | 25     4      25    | 9      8      6     |
| 48     6      58    |#13     9     #13    | 45     7      2     |
| 249    2459   259   | 6      7      8     | 3      14     145   |
:---------------------+---------------------+---------------------:
| 2489   24589  12689 |#1349   16    #1369  | 7      13469  13459 |
| 1469   7      3     | 8      5      169   | 2      1469   149   |
| 1469   459    1569  | 1349   2      7     | 45     13469  8     |
'---------------------'---------------------'---------------------'


I have a question...

the cells marked form what I think is a UR, but it doesn't eliminate two candidates, it only eliminates one... hmm. I think its been discussed before that you can have two sides of the UR be conjugate on one of the candidates and therefore it will only eliminate one of the "floor" candidates?

in this case, the candidate that is conjugate on two sides is 3
is this the case always??
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Victor



Joined: 29 Sep 2005
Posts: 207
Location: NI

PostPosted: Tue Apr 29, 2008 8:33 am    Post subject: Reply with quote

I know types 1 - 4 automatically, but think about others on a need-to-know basis. I.e. I recognise the easy ones without thought, but just mentally figure out others as needed. It's usually the case (and of course always is in this kind) that the number you can eliminate is the one that doesn't have the strong link, and it'll be on the opposite side.
Here, you can eliminate the 1 form the bottom left cell. Trye it mentally: run round the 4 cells clockwise. If that's a 1, then next is 3, then next is 1 and, punchline, bottom right must be 3 because of the strong link.

Hope that helps.

PS one rule I find helpful in UR situations is as follows:
If there are 2 naked pairs, then you need one (more) conjugate link to be able to make an elimination.
If there's just one naked pair, then you need 2 conjugate links.
If there are no naked prs, then you need 3 conjugate links.
Not that these are necessary, but may not always be sufficient.
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Tue Apr 29, 2008 1:08 pm    Post subject: Reply with quote

Asellus wrote:
There's a nice Sashimi Swordfish right at the start that eliminates <4> in r5c1 and moves things along.
Nice find, its also a grouped kite:
Code:
+---------------------+--------------+----------------+
| 5      2389  1289   | 7    18 29   | 6  2349  349   |
| 16     29    4      | 15   3  156  | 8  29    7     |
| 7      2389  2689   | 29   68 4    | 1  5     39    |
+---------------------+--------------+----------------+
| 3      1     7      | 25   4  25   | 9  8     6     |
|-48     6     58     | 13   9  13   |#45 7     2     |
| 249    2459  259    | 6    7  8    | 3  14    145   |
+---------------------+--------------+----------------+
| 124689 24589 125689 | 1349 16 1369 | 7  13469 13459 |
|@1469   7     3      | 8    5  169  | 2 @1469 @149   |
| 1469   459   1569   | 1349 2  7    |#45 13469 8     |
+---------------------+--------------+----------------+
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