SudoCue Users Forum Index SudoCue Users
A forum for users of the SudoCue programs and the services of SudoCue.Net
 
 FAQFAQ   SearchSearch   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

17 April 2007

 
Post new topic   Reply to topic    SudoCue Users Forum Index -> Daily Sudoku Nightmare & Archive
View previous topic :: View next topic  
Author Message
Ron Moore
Addict
Addict


Joined: 13 Aug 2006
Posts: 72
Location: New Mexico

PostPosted: Wed Apr 18, 2007 8:24 pm    Post subject: 17 April 2007 Reply with quote

[Edited to correct error in start position noted by Mike below]

Start position for the 17 April 2007 Daily Nightmare

Code:

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

This is the position after initial basic eliminations:

Code:
.------------------.-------------------.------------------.
| 68    39    7    | 1389   189   5    | 469   2     134  |
| 39    2     1    |*379    6     4    | 79    5     8    |
| 4     5     68   | 2     #1789  138  | 679   1369 *137  |
:------------------+-------------------+------------------:
| 678   4     2    | 138    5     138  | 678   168   9    |
| 389   1     389  | 6      289   7    | 258   4     25   |
| 5    *79    689  | 189    4     128  | 3     168  #127  |
:------------------+-------------------+------------------:
| 237  #37    345  | 158-7  1278  9    | 2458  38    6    |
| 1     6     459  | 58     3     28   | 24589 7     245  |
| 2379  8     359  | 4      27    6    | 1     39    235  |
'------------------'-------------------'------------------'


The following AIC for digit 7 is enough to complete the puzzle with only singles thereafter. (Cells in the chain are alternately marked with "*" and "#" in the diagram.)
    (7): r2c4 = r3c5 - r3c9 = r6c9 - r6c2 = r7c2 => r7c4 <> 7


Last edited by Ron Moore on Tue Apr 24, 2007 1:25 am; edited 2 times in total
Back to top
View user's profile Send private message
Para
Yokozuna
Yokozuna


Joined: 08 Nov 2006
Posts: 384
Location: The Netherlands

PostPosted: Wed Apr 18, 2007 9:23 pm    Post subject: Re: 17 April 2007 Reply with quote

Hi


I generally prefer looking in patterns when solving sudoku's.
This can be recreated with this Finned Swordfish on 7 in C259 with R9C5 being the fin.

Code:
.------------------.-------------------.------------------.
| 68    39    7    | 1389   189   5    | 469   2     134  |
| 39    2     1    | 379    6     4    | 79    5     8    |
| 4     5     68   | 2     *1789  138  | 679   1369 *137  |
:------------------+-------------------+------------------:
| 678   4     2    | 138    5     138  | 678   168   9    |
| 389   1     389  | 6      289   7    | 258   4     25   |
| 5    *79    689  | 189    4     128  | 3     168  *127  |
:------------------+-------------------+------------------:
| 237  *37    345  | 158-7 *1278  9    | 2458  38    6    |
| 1     6     459  | 58     3     28   | 24589 7     245  |
| 2379  8     359  | 4     #27    6    | 1     39    235  |
'------------------'-------------------'------------------'


greetings

Para
Back to top
View user's profile Send private message
mhparker
Grandmaster
Grandmaster


Joined: 20 Jan 2007
Posts: 345
Location: Germany

PostPosted: Thu Apr 19, 2007 7:19 pm    Post subject: Reply with quote

As I understand it, Para's finned Swordfish would actually be equivalent to the AIC:

(7): r79c5 = r3c5 - r3c9 = r6c9 - r6c2 = r7c2 => r7c4 <> 7

where the fin belongs to the grouped node r79c5.

By the way, Ron, your "Start position" grid is incorrect in the top band. Maybe you can quickly fix that? Thanks.
_________________
Cheers,
Mike
Back to top
View user's profile Send private message
Ron Moore
Addict
Addict


Joined: 13 Aug 2006
Posts: 72
Location: New Mexico

PostPosted: Tue Apr 24, 2007 1:25 am    Post subject: Reply with quote

Original post edited to correct the error Mike spotted -- thanks.

Yes, there's more than one way to view this. Grouped AIC's like the one Mike gives can always be written for empty rectangle and finned X-wing eliminations, and for finned 2-2-2 swordfish patterns like this one.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SudoCue Users Forum Index -> Daily Sudoku Nightmare & Archive 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