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 

Mar 17 VH

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



Joined: 24 Apr 2006
Posts: 1110
Location: Dar es Salaam Tanzania

PostPosted: Fri Mar 16, 2012 10:51 pm    Post subject: Mar 17 VH Reply with quote

After the Basics
Code:

+--------+------------+----------+
| 9  8 3 | 7  1   26  | 26 4  5  |
| 6  4 1 | -89 258 259 | 28 3  7  |
| 7  2 5 | 3  68  4   | 1  68 9  |
+--------+------------+----------+
| 1  9 4 | 68 27  27  | 3  5  68 |
| 38 5 2 | 4  9   36  | 68 7  1  |
| 38 7 6 | 1  58  35  | 4  9  2  |
+--------+------------+----------+
| 5  3 7 | 2  4   1   | 9  68 68 |
| 4  1 8 | 69 67  679 | 5  2  3  |
| 2  6 9 | 5  3   8   | 7  1  4  |
+--------+------------+----------+
Remote pairs on 68; r2c4<>8 solves it.
Back to top
View user's profile Send private message AIM Address
Marty R.



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

PostPosted: Sat Mar 17, 2012 3:46 am    Post subject: Re: Mar 17 VH Reply with quote

Clement wrote:
After the Basics
Code:

+--------+------------+----------+
| 9  8 3 | 7  1   26  | 26 4  5  |
| 6  4 1 | -89 258 259 | 28 3  7  |
| 7  2 5 | 3  68  4   | 1  68 9  |
+--------+------------+----------+
| 1  9 4 | 68 27  27  | 3  5  68 |
| 38 5 2 | 4  9   36  | 68 7  1  |
| 38 7 6 | 1  58  35  | 4  9  2  |
+--------+------------+----------+
| 5  3 7 | 2  4   1   | 9  68 68 |
| 4  1 8 | 69 67  679 | 5  2  3  |
| 2  6 9 | 5  3   8   | 7  1  4  |
+--------+------------+----------+
Remote pairs on 68; r2c4<>8 solves it.

I used the 896 XY-Wing pivoted in r2c4; r8c5<>6. I can't find the Remote Pairs. The closest I can come is Simple Coloring, 68-68-68-28.
Back to top
View user's profile Send private message
Clement



Joined: 24 Apr 2006
Posts: 1110
Location: Dar es Salaam Tanzania

PostPosted: Sat Mar 17, 2012 7:10 am    Post subject: Re: Mar 17 VH Reply with quote

Marty R. wrote:
Clement wrote:
After the Basics
Code:

+--------+------------+----------+
| 9  8 3 | 7  1   26  | 26 4  5  |
| 6  4 1 | -89 258 259 | 28 3  7  |
| 7  2 5 | 3  68  4   | 1  68 9  |
+--------+------------+----------+
| 1  9 4 | 68 27  27  | 3  5  68 |
| 38 5 2 | 4  9   36  | 68 7  1  |
| 38 7 6 | 1  58  35  | 4  9  2  |
+--------+------------+----------+
| 5  3 7 | 2  4   1   | 9  68 68 |
| 4  1 8 | 69 67  679 | 5  2  3  |
| 2  6 9 | 5  3   8   | 7  1  4  |
+--------+------------+----------+
Remote pairs on 68; r2c4<>8 solves it.

I used the 896 XY-Wing pivoted in r2c4; r8c5<>6. I can't find the Remote Pairs. The closest I can come is Simple Coloring, 68-68-68-28.
The remote pairs I am refering in my Grid are as follows:
Code:

+--------+------------+----------+
| 9  8 3 | 7  1   26  | 26 4  5  |
| 6  4 1 | 89 258 259 | 28 3  7  |
| 7  2 5 | 3  A68  4   | 1  B68 9  |
+--------+------------+----------+
| 1  9 4 | F68 27  27  | 3  5  E68 |
| 38 5 2 | 4  9   36  | 68 7  1  |
| 38 7 6 | 1  58  35  | 4  9  2  |
+--------+------------+----------+
| 5  3 7 | 2  4   1   | 9  C68 D68 |
| 4  1 8 | 69 67  679 | 5  2  3  |
| 2  6 9 | 5  3   8   | 7  1  4  |
+--------+------------+----------+
A->B->C->D->E->F. A and F can see r2c4; r2c4<>8. Pairs can be used to remove a single candidate. If you like you can refer this route as singles chains on 8.
Back to top
View user's profile Send private message AIM Address
skegbyrd



Joined: 17 Mar 2012
Posts: 2

PostPosted: Sat Mar 17, 2012 9:58 am    Post subject: Reply with quote

I don't understand x wings. I solved it with, r2 c 5, 6 & 7. 258, 25, 28 so r2 c4 must be 9.
Back to top
View user's profile Send private message Send e-mail
hughwill



Joined: 05 Apr 2010
Posts: 422
Location: Birmingham UK

PostPosted: Sat Mar 17, 2012 10:15 am    Post subject: Re: Mar 17 VH Reply with quote

Clement's chain also sets r6c5 to 5 solving the puzzle. I couldn't get as far as
Skegbyrd with basics to remove the 2 from r2c5 and the 9 from r2c6......

But the humdrum XY wing 896 did the job for me- I'm sure someone
(Marty, Arkitech?)will point Skegbyrd in the direction of one of the great
explanations of wings opening up a whole new world of solving!
Back to top
View user's profile Send private message
arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sat Mar 17, 2012 11:47 am    Post subject: Reply with quote

skegbyrd wrote:
I don't understand x wings.


The best way to understand the xy-wing is go to the pivot. In this case it is r2c4 with two possible candidates 8 or 9.

If r2c4 is an 8 then r2c5 is a 6.

If r2c4 is an 9 then r8c4 is a 6.

This means r8c5 cannot be a 6.

This solves ther puzzle .. (only singles remain).

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



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

PostPosted: Sat Mar 17, 2012 12:01 pm    Post subject: Reply with quote

Quote:
A->B->C->D->E->F. A and F can see r2c4; r2c4<>8.


Clement, thanks for straightening me out. I should have been able to spot that. Embarassed
Back to top
View user's profile Send private message
Marty R.



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

PostPosted: Sat Mar 17, 2012 12:11 pm    Post subject: Reply with quote

Quote:
I don't understand x wings.


Skegbyrd, this explains many of the techniques that are frequently used and discussed here.

http://www.sadmansoftware.com/sudoku/solvingtechniques.htm
Back to top
View user's profile Send private message
skegbyrd



Joined: 17 Mar 2012
Posts: 2

PostPosted: Sun Mar 18, 2012 9:23 am    Post subject: xy wing Reply with quote

I think I have it but you made it a little more difficult saying r2 c5 is a 6 when I think you meant r3 c5. I have read various articles trying to explain them but yours was the best. Thanks.
Back to top
View user's profile Send private message Send e-mail
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