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 

Help w/ June 24

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



Joined: 24 Jun 2006
Posts: 1

PostPosted: Sat Jun 24, 2006 1:40 pm    Post subject: Help w/ June 24 Reply with quote

So far I have:

9-- -15 463
-41 --3 895
35- 94- 172

--3 5-- 914
417 369 528
5-9 4-1 637

-95 -34 -81
1-- -5- 349
1-- -5- 349

The hint says put 2 in r4c1.
Why?

Thanks, phil
Back to top
View user's profile Send private message
David Bryant



Joined: 29 Jul 2005
Posts: 559
Location: Denver, Colorado

PostPosted: Sat Jun 24, 2006 5:09 pm    Post subject: Double X-Wing Reply with quote

Hi, Phil!

I think you've repeated row 8 twice in your post above. Here's what the puzzle looked like when I arrived at the same crunch point.
Code:
9-- -15 463
-41 --3 895
35- 94- 172

--3 5-- 914
417 369 528
5-9 4-1 637

-95 -34 -81
1-- -5- 349
834 19- -56

From here I had to identify two successive X-Wings to solve the puzzle.

1. There are only two ways to fit a "7" in row 1. Similarly, there are only two ways to fit a "7" in row 8. So you can use an X-Wing on "7"s (r1c24 & r8c24) to eliminate the possibility of a "7" in r2c4 & in r7c4.

After making these eliminations you will find the hidden pair {2, 6} lying in r2c4 & r7c4, implying that the only possibilities at r1c4 & r8c4 are {7, 8}.

2. Now you can identify a second X-Wing, on the digit "2", in r1c23 and r8c23. This X-Wing pattern lets you eliminate the possibility of a "2" at r4c2 & r6c2, leading to the conclusion that r4c1 = 2. dcb
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Steve R



Joined: 24 Oct 2005
Posts: 289
Location: Birmingham, England

PostPosted: Sat Jun 24, 2006 5:29 pm    Post subject: Reply with quote

I think one flight will do on a Saturday.

Is there not an X-wing for 6 based on rows 2 and 7 which eliminates 6 from r4c1, leaving 2 as the only admissible candidate?

Steve
Back to top
View user's profile Send private message
Clement



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

PostPosted: Mon Jun 26, 2006 2:22 pm    Post subject: Daily Sudoku: Sat24-Jun-2006 Reply with quote

Steve R

I am not very conversant with THE X-Wing
Why did you choose 6 as a base on rows 2 & 7 why not 2? Because the position was like this:-

267 267





267 267

Thus leaving 6 as the only admissible candidate in r4c1?
Back to top
View user's profile Send private message AIM Address
TKiel



Joined: 22 Feb 2006
Posts: 292
Location: Kalamazoo, MI

PostPosted: Mon Jun 26, 2006 9:20 pm    Post subject: Reply with quote

An x-wing can only have two possibilities for the particular number in either each row or in each column. 2's appear three times in each row and 3 times in one column & 4 times in the other.
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