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 

Oct 10 VH
Goto page Previous  1, 2
 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Daily Sudoku puzzles
View previous topic :: View next topic  
Author Message
Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium
PostPosted: Fri Oct 12, 2007 8:34 am    Post subject: Reply with quote
Quote:

In your B grid from your second post, you end up with 2 +'s in the same box. If + means = 1, how can this be?


Tracy,

You're right it is deceptive with 2 +'s in the same box, what i really meant is that one of those 2 +'s must be 1 in C6 of that box, when R6C4 has a <->value, which results in a <->value in C6 from box 8.
Back to top
View user's profile Send private message Send e-mail
keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Sun Oct 14, 2007 6:42 pm    Post subject: Reply with quote
This is a great puzzle!

You can solve it using only wings as advanced moves. In this order: XY, XYZ, X, XY, XY, and XY.

But, there seem to be lots of ways through this one: I had a Unique X-wing on <18>, a W-wing, a UR, which revealed a swordfish, ...

(Recall: Up to now, all the "Very Hard" puzzles can be solved with only X, XY, and XYZ-wings as "advanced" moves.)

Keith
Back to top
View user's profile Send private message
TKiel



Joined: 22 Feb 2006
Posts: 292
Location: Kalamazoo, MI
PostPosted: Sun Oct 14, 2007 7:51 pm    Post subject: Reply with quote
sdq_pete wrote:
Observing the 12 candidate pairs in blocks 3, 6 and 9, I noticed that whatever value R9C7 took, R6C9 must be 1. Intuitively, I suspect this is related to Johan's links. But can anyone identify any further x-moves here?


The pair of <12> cells (r9c7 & r6c9) are part of a W-wing, (strong links on <2>).

Johan,

Now I see. A system to mark grouped coloring has always presented problems for me. I wish there were a better way to do it (when it's not in a W-wing format) because I think it is an under-utilized technique.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Daily Sudoku puzzles All times are GMT
Goto page Previous  1, 2
Page 2 of 2

 
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