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 

July 11 DB

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



Joined: 30 May 2007
Posts: 677
Location: Victoria, KS
PostPosted: Sat Jul 11, 2009 2:30 pm    Post subject: July 11 DB Reply with quote
The July 11 DB is not a single shot. Norm, please prove me wrong!

Complex Solution: xy-chain eliminates 6 in R1C9, xy-chain eliminates 9 in R4C3, xy-wing (568) eliminates 5 in R3C2 and solves the puzzle.


Earl

Code:

+-------+-------+-------+
| 4 . . | . 2 . | 1 . . |
| . 6 . | 1 . . | . 3 4 |
| . . . | . 8 . | . . 9 |
+-------+-------+-------+
| . . . | . . . | 7 5 . |
| 5 . 6 | . . . | 2 . 8 |
| . 3 2 | . . . | . . . |
+-------+-------+-------+
| 9 . . | . 6 . | . . . |
| 1 7 . | . . 8 | . 4 . |
| . . 3 | . 4 . | . . 5 |
+-------+-------+-------+

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



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sat Jul 11, 2009 5:39 pm    Post subject: Reply with quote
got it.
Code:
.---------------------.---------------------.---------------------.
| 4      589    89    | 3569   2      3569  | 1      678    67    |
| 2      6    *7-89   | 1     *579    579   |*58     3      4     |
| 3     *15    *17    | 4567   8      4567  | 56     2      9     |
:---------------------+---------------------+---------------------:
| 8      149    149   | 26     19     26    | 7      5      3     |
| 5     *19     6     | 347    37     347   | 2     *19     8     |
| 7      3      2     | 8     *159   *59    | 4     *169    16    |
:---------------------+---------------------+---------------------:
| 9      248    48    | 2357   6      12357 | 38     178    127   |
| 1      7      5     | 239    39     8     | 369    4      26    |
| 6      28     3     | 279    4      1279  | 89     178    5     |
'---------------------'---------------------'---------------------'

(8=5)r2c7 - (5)r2c5 = (5)r6c5 - (5=9)r6c6 - (9)r6c8 = (9)r5c8 - (9=1)r5c2 - (1)r3c2 = (1-7)r3c3 = (7)r2c3; r2c3 <> 8
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Sat Jul 11, 2009 6:41 pm    Post subject: Reply with quote
There is a potential DP (89-49-48) in boxes 1-4-7. Any of the ways to kill it (5 in r1c2, 1 in r4c2 or r4c3, and 2 in r7c2) results in a few cells forced and that solves it.
Back to top
View user's profile Send private message
ttt



Joined: 06 Dec 2008
Posts: 42
Location: vietnam
PostPosted: Sat Jul 11, 2009 6:45 pm    Post subject: Reply with quote
storm_norm wrote:
got it.
Code:
.---------------------.---------------------.---------------------.
| 4      589    89    | 3569   2      3569  | 1      678    67    |
| 2      6    *7-89   | 1     *579    579   |*58     3      4     |
| 3     *15    *17    | 4567   8      4567  | 56     2      9     |
:---------------------+---------------------+---------------------:
| 8      149    149   | 26     19     26    | 7      5      3     |
| 5     *19     6     | 347    37     347   | 2     *19     8     |
| 7      3      2     | 8     *159   *59    | 4     *169    16    |
:---------------------+---------------------+---------------------:
| 9      248    48    | 2357   6      12357 | 38     178    127   |
| 1      7      5     | 239    39     8     | 369    4      26    |
| 6      28     3     | 279    4      1279  | 89     178    5     |
'---------------------'---------------------'---------------------'

(8=5)r2c7 - (5)r2c5 = (5)r6c5 - (5=9)r6c6 - (9)r6c8 = (9)r5c8 - (9=1)r5c2 - (1)r3c2 = (1-7)r3c3 = (7)r2c3; r2c3 <> 8

Why don’t use our favourite technique… Very Happy. Look at AUR(59)r26c56 => at least one of [(1)r6c5, (7)r2c56] must be true:
(1)r6c5=(7)r2c56-(7)r2c3=(7-1)r3c3=(1)r3c2-(1)r5c2=(1)r5c8 => r6c89<>1

ttt
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other 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