dailysudoku.com Forum Index dailysudoku.com
Discussion of Daily Sudoku puzzles
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Big finny fish.

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles
View previous topic :: View next topic  
Author Message
wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Thu Feb 05, 2009 3:36 pm    Post subject: Big finny fish. Reply with quote
This one is a 2 big-step or a 5-step advanced.

I see a finned jellyfish and a sashimi swordfish.
Advanced players may see an x, xy, xyz, and 2 W-wings.

Code:
. . 8|. 5 1|. . .
7 . 6|3 . .|. . .
. 3 .|6 . 4|. 7 .
-----+-----+-----
. 1 .|. . .|. 8 9
. . 5|. . .|6 . .
6 8 .|. . .|. 3 .
-----+-----+-----
. 4 .|1 . 3|. 6 .
. . .|. . 6|7 . 2
. . .|5 7 .|1 . .
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Thu Feb 05, 2009 6:39 pm    Post subject: Re: Big finny fish. Reply with quote
wapati wrote:
This one is a 2 big-step or a 5-step advanced.

I see a finned jellyfish and a sashimi swordfish.
Advanced players may see an x, xy, xyz, and 2 W-wings.

You might wish to review how many of the highlighted steps you needed before getting to the finned Jellyfish and Sashimi Swordfish.
Back to top
View user's profile Send private message
wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Thu Feb 05, 2009 6:50 pm    Post subject: Reply with quote
Here is my first step after easy stuff, a finned jelly.
The fins are marked "#".

Code:
.------------------.------------------.------------------.
| 4     29    8    | 7     5     1    | 3     29    6    |
| 7     259   6    | 3     289   29   | 2489  1259  14   |
| 159   3     19   | 6    *289   4    |*289   7     58   |
:------------------+------------------+------------------:
|*23    1    #234  |*24    6     7    | 5     8     9    |
| 9-2   7     5    | 249   3     8    | 6     12    14   |
| 6     8    #249  |*249   1     5    |*24    3     7    |
:------------------+------------------+------------------:
|*259   4     7    | 1    *29    3    | 89    6     58   |
| 13    59    13   | 8     4     6    | 7     59    2    |
| 8     6     29   | 5     7     29   | 1     4     3    |
'------------------'------------------'------------------'
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Thu Feb 05, 2009 7:49 pm    Post subject: Reply with quote
My oversight and my apologies. Embarassed

I stopped at ...

Code:
 finned Franken Swordfish r37b6\c157 => [r5c1]<>2
 +--------------------------------------------------------------+
 |  4     29    8     |  7     5     1     |  3     29    6     |
 |  7     259   6     |  3     289   29    |  2489  1259  14    |
 |  159   3     19    |  6    *289   4     | *289   7     58    |
 |--------------------+--------------------+--------------------|
 |  23    1     234   |  24    6     7     |  5     8     9     |
 |  9-2   7     5     |  249   3     8     |  6    #12    14    |
 |  6     8     249   |  249   1     5     | *24    3     7     |
 |--------------------+--------------------+--------------------|
 | *259   4     7     |  1    *29    3     |  89    6     58    |
 |  13    59    13    |  8     4     6     |  7     59    2     |
 |  8     6     29    |  5     7     29    |  1     4     3     |
 +--------------------------------------------------------------+
 # 47 eliminations remain

... and missed the finned Jellyfish for the same elimination.
Back to top
View user's profile Send private message
ronk



Joined: 07 May 2006
Posts: 398
PostPosted: Thu Feb 05, 2009 10:01 pm    Post subject: Reply with quote
daj95376 wrote:
finned Franken Swordfish r37b6\c157 => [r5c1]<>2

With only one fish group candidate (occupied vertex) in cover column c1, this is sashimi.
Back to top
View user's profile Send private message
storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sat Feb 07, 2009 3:48 am    Post subject: Reply with quote
i'd like to try some UR inferences with this one. not sure if this is the correct way to look at these.

Code:
.------------------.------------------.------------------.
| 4     29    8    | 7     5     1    | 3     29    6    |
| 7     259   6    | 3   2[89]   29   |24[89] 1259  14   |
| 159   3     19   | 6   2[89]   4    |2[89]  7     58   |
:------------------+------------------+------------------:
| 23    1     234  | 24    6     7    | 5     8     9    |
| 29    7     5    | 249   3     8    | 6     12    14   |
| 6     8     249  | 249   1     5    | 24    3     7    |
:------------------+------------------+------------------:
|25-9   4     7    | 1    *29    3    |*89    6     58   |
| 13   *59    13   | 8     4     6    | 7    *59    2    |
| 8     6     29   | 5     7    2-9   | 1     4     3    |
'------------------'------------------'------------------'

first of all, if the 2's in r23c5 are not true, then you get the UR{8,9}r23c57. then, in order to avoid the deadly pattern, both the 8 and the 9 in r7c7 cannot both be false or that would force the deadly pattern to exist.

so the inference can be made on the 2's in r23c5 AND both the 8 and the 9 in r7c7 because both can't be false.

inference made is... UR89[(2)r23c5 = (9)r7c7]
and
UR89[(2)r23c5 = (8)r7c7]

now, the first one can be used in this manner
(9=2)r7c5 - UR89[(2)r23c5 = (9)r7c7]; r7c1 <> 9

once that 9 in eliminated...

the second one
(9=2)r7c5 - UR89[(2)r23c5 = (8)r7c7] - (8=5)r7c9 - (5)r8c8 = (5-9)r8c2 = (9)r9c3; r9c6 <> 9
that would solve it.

I'd like to know if my thoughts are correct on these.

the reason I feel its a fluke because the real inference should be written like
UR89[(2)r23c5 = (8=9)r7c7]

right? Question
Back to top
View user's profile Send private message
Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
PostPosted: Sat Feb 07, 2009 9:11 am    Post subject: Reply with quote
Norm,

I'm afraid I can't follow you.
Quote:
then, in order to avoid the deadly pattern, both the 8 and the 9 in r7c7 cannot both be false

Well, actually, the <8> and <9> in r7c7 cannot both be false because it's a bivalue cell. A potential UR somewhere has nothing to do with it. In fact, the existence of that 89 bivalue destroys your potential 89 UR. So, your reasoning is circular.

I can't see any useful UR exploits in the grid. But, maybe someone else can.
Back to top
View user's profile Send private message Visit poster's website
storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sat Feb 07, 2009 3:47 pm    Post subject: Reply with quote
Asellus wrote:
Norm,

I'm afraid I can't follow you.
Quote:
then, in order to avoid the deadly pattern, both the 8 and the 9 in r7c7 cannot both be false

Well, actually, the <8> and <9> in r7c7 cannot both be false because it's a bivalue cell. A potential UR somewhere has nothing to do with it. In fact, the existence of that 89 bivalue destroys your potential 89 UR. So, your reasoning is circular.

I can't see any useful UR exploits in the grid. But, maybe someone else can.


ohhh,
I guess that was some big dreaming.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group