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 

May 31 VH

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Daily Sudoku puzzles
View previous topic :: View next topic  
Author Message
Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

PostPosted: Sun May 31, 2009 1:44 am    Post subject: May 31 VH Reply with quote

It's high time we had a VH.

A TOWERING SOLUTION: a skyscraper <8> clears the path.

Early Earl
Back to top
View user's profile Send private message Send e-mail
storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Sun May 31, 2009 3:32 am    Post subject: Reply with quote

Quote:
It's high time we had a VH.

Earl,
May I remind you that Danny posts Very Hard puzzles in his forum everyday?


Last edited by storm_norm on Sun May 31, 2009 5:35 am; edited 1 time in total
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun May 31, 2009 4:45 am    Post subject: Reply with quote

A W-Wing on 89 does it too. I'll echo Norm's suggestion to take a look at Danny's puzzles.
Back to top
View user's profile Send private message
crunched



Joined: 05 Feb 2008
Posts: 168

PostPosted: Sun May 31, 2009 7:18 am    Post subject: Reply with quote

An x-y wing does it.
Below (all?) is stripped to the basics.
Code:

+-------------+-----------------+---------------+
| 9   4  1    | 357  23567  236 | 236 278 2378  |
| 37  5  8    | 37   26     9   | 26  4   1     |
| 37  6  2    | 1    4      8   | 9   57  357   |
+-------------+-----------------+---------------+
| 1   7  59   | 6    89     4   | 25  3   258   |
| 6   89 359  | 2    389    7   | 1   58  4     |
| 48  2  34   | 38   1      5   | 7   9   6     |
+-------------+-----------------+---------------+
| 58  1  6    | 9    23578  23  | 4   257 2357  |
| 2   3  579  | 4    57     1   | 8   6   579   |
| 458 89 4579 | 3578 235678 236 | 235 1   23579 |
+-------------+-----------------+---------------+

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



Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania

PostPosted: Sun May 31, 2009 10:50 am    Post subject: Daily Sudoku: Sun 31-May-2009 VH Reply with quote

Finned X-Wing on 8 solves the puzzle.
There is a potential X-Wing on 8 in columns 1&4 i.e r69c14. The fin rule allows us to remove the 8 in r9c2 because, it shares the same unit (BOX) as the fin cell in r7c1.
Back to top
View user's profile Send private message AIM Address
Earl



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

PostPosted: Sun May 31, 2009 3:39 pm    Post subject: May 31 VH Reply with quote

"It's high time we had a VH" is a pun on the solution technique, a skyscraper.

Am I too subtle or too dense?

Earl


Last edited by Earl on Mon Jun 01, 2009 4:41 pm; edited 1 time in total
Back to top
View user's profile Send private message Send e-mail
gindaani



Joined: 06 Mar 2009
Posts: 79

PostPosted: Mon Jun 01, 2009 1:06 am    Post subject: Reply with quote

The typical xy-wing is all it took for me. An 895 xy-wing for this one.

(I've taken to listing the pivot first in my xy-wing designations. So in this case 89 is the pivot. I think it makes them easier to spot.)
Back to top
View user's profile Send private message
keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Mon Jun 01, 2009 2:49 am    Post subject: Reply with quote

gindaani wrote:
The typical xy-wing is all it took for me. An 895 xy-wing for this one.

(I've taken to listing the pivot first in my xy-wing designations. So in this case 89 is the pivot. I think it makes them easier to spot.)


Or, you could say -589 where the - precedes the pincer candidate in any chain.

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



Joined: 06 Jan 2008
Posts: 6
Location: Adelaide

PostPosted: Sun Jun 07, 2009 4:38 am    Post subject: anyone can help to clarify Reply with quote

Dear posters,

I have got my puzzle to the bare bones as shown above, and have read the discussion here, studied xy wings and skyscrapers, but am not sure how to go ahead with it. Has anyone got the time to point out how the next steps would work?

thanks, sue
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sun Jun 07, 2009 5:16 am    Post subject: Reply with quote

Sue,

If you've studied XY-Wings, then you know the basic rule. We start with a cell we call XY. That cell must see both an XZ and a YZ, then any cell that can see both XZ and YZ cannot contain Z. Our XY is the 89 in r5c2. The XZ is the 58 in r5c8 and the YZ is the 59 in r4c3. Thus, obviously, the Z is 5. Both r5c3 and r4c9 see both the XZ (58) and YZ (59), thus neither cell may contain Z (5).

Hope this helps.
Back to top
View user's profile Send private message
crunched



Joined: 05 Feb 2008
Posts: 168

PostPosted: Sun Jun 07, 2009 5:33 am    Post subject: Re: anyone can help to clarify Reply with quote

Sue wrote:
Dear posters,

I have got my puzzle to the bare bones as shown above, and have read the discussion here, studied xy wings and skyscrapers, but am not sure how to go ahead with it. Has anyone got the time to point out how the next steps would work?

thanks, sue


There is a star beside each of the xy pairs (89 59 58 ). The 89 is called the pivot. The 58 and the 59 are the "pincers" each containing a 5. They both "see" or touch the 5 in the cell with 25 and the cell with 258 in row 4 (marked with #). This removes those fives in the cells marked by #. One could also say that 58 and 59 are 2 wings stemming from the 89 cell, and that any number that is the same as the number that the wings have in common (5 in this case) can be brushed away.

Code:

+-------------+-----------------+---------------+
| 9   4  1    | 357  23567  236 | 236 278 2378  |
| 37  5  8    | 37   26     9   | 26  4   1     |
| 37  6  2    | 1    4      8   | 9   57  357   |
+-------------+-----------------+---------------+
| 1   7 *59   | 6    89     4   |#25  3  #258   |
| 6  *89 359  | 2    389    7   | 1  *58  4     |
| 48  2  34   | 38   1      5   | 7   9   6     |
+-------------+-----------------+---------------+
| 58  1  6    | 9    23578  23  | 4   257 2357  |
| 2   3  579  | 4    57     1   | 8   6   579   |
| 458 89 4579 | 3578 235678 236 | 235 1   23579 |
+-------------+-----------------+---------------+

Play this puzzle online at the Daily Sudoku site[/quote]
Back to top
View user's profile Send private message
Sue



Joined: 06 Jan 2008
Posts: 6
Location: Adelaide

PostPosted: Sun Jun 07, 2009 5:41 am    Post subject: Reply with quote

Got it!

thats brilliant, thank you both of you
Back to top
View user's profile Send private message
Sue



Joined: 06 Jan 2008
Posts: 6
Location: Adelaide

PostPosted: Sun Jun 07, 2009 5:48 am    Post subject: Reply with quote

I am looking at it again, and it seems that 58 can also be the pivot, and pince out the 9 in row5 column 3
Back to top
View user's profile Send private message
Sue



Joined: 06 Jan 2008
Posts: 6
Location: Adelaide

PostPosted: Sun Jun 07, 2009 5:50 am    Post subject: Reply with quote

Ha! I'm wrong. Duh
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
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