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 

Set F Puzzle 18

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj
View previous topic :: View next topic  
Author Message
daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sat Dec 06, 2008 7:08 am    Post subject: Set F Puzzle 18 Reply with quote
Enjoy the basics.

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

Play this puzzle online at the Daily Sudoku site
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sun Dec 07, 2008 1:40 pm    Post subject: Reply with quote
Code:
 +-----------------------------------------------------------------------+
 |  6      4      1239   |  29     7      15     |  39     59     8      |
 |  8      5      29     |  4      26     3      |  679    1      679    |
 |  139    139    7      |  69     8      15     |  3469   4569   2      |
 |-----------------------+-----------------------+-----------------------|
 |  47     8      59     |  1      49     6      |  2      3      4579   |
 |  2      139    1359   |  7      49     8      |  1469   469    14569  |
 |  47     6      19     |  5      3      2      |  1479   8      1479   |
 |-----------------------+-----------------------+-----------------------|
 |  139    1379   6      |  8      12     79     |  5      249    149    |
 |  159    2      8      |  3      156    4      |  169    7      169    |
 |  159    179    4      |  26     1256   79     |  8      269    3      |
 +-----------------------------------------------------------------------+
 # 84 eliminations remain

         XY-Wing  [r2c5]/[r2c3]+[r3c4]   <> 9    [r3c12]
         ...
         XY-Wing  [r9c4]/[r3c4]+[r9c8]   <> 9    [r3c8]
Back to top
View user's profile Send private message
storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Mon Dec 08, 2008 2:41 am    Post subject: Reply with quote
I was hoping this situation would come up in one of these puzzles.

we have seen how a hinged/grouped link within a box can be used to form a w-wing.

you can use that same inference in a row or a column

as shown below.
this image is the state of the puzzle after a xy-wing {2,6,9} and some basics.

the black lines represent the links on 9 and the red lines are the pincers from the 6's

notice that the 9 in r3c8 is strongly linked to the group of 9's in col 8 in box 9. (they both cannot be false) this makes it possible to connect the w-wing with the {6,9} cells.

you have the w-wing {6,9} via the strong link between the 9 in r3c8 and the group of 9's in r79c8.

(6=9)r8c7 - (9)r79c8 = (9)r3c8 - (9=6)r4c4; r4c7 <> 6
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Puzzles by daj 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