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 

au 3/3/12 tough

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



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
PostPosted: Sat Mar 03, 2012 9:29 pm    Post subject: au 3/3/12 tough Reply with quote
Code:
*-----------*
 |...|..7|...|
 |.3.|..1|.6.|
 |...|.8.|72.|
 |---+---+---|
 |..4|.76|...|
 |..9|...|5..|
 |...|12.|8..|
 |---+---+---|
 |.52|.3.|...|
 |.8.|6..|.9.|
 |...|4..|...|
 *-----------*
 *-----------------------------------------------------------*
 | 125   4     158   | 29    6     7     | 19    5-8   3     |
 | 27    3     7-8   | 29    5     1     | 4     6     89    |
 | 156   9     156   | 3     8     4     | 7     2     15    |
 |-------------------+-------------------+-------------------|
 | 8     12    4     | 5     7     6     | 19    3     129   |
 | 167   1267  9     | 8     4     3     | 5     17    126   |
 | 35    67    35    | 1     2     9     | 8     47    46    |
 |-------------------+-------------------+-------------------|
 | 9     5     2     | 7     3     8     | 6     14    14    |
 | 4     8     37    | 6     1     25    | 23    9     57    |
 | 1367  167   1367  | 4     9     25    | 23    58    578   |
 *-----------------------------------------------------------*
XY-Chain r8c3<>7 => r1c3= 18
XY-Wing 198 => r1c8,r2c3<>8

(7=8)r2c3-(8-9)r2c9-(9=1)r1c7-(1=5)r3c9-(5=7)r8c9
=> r8c3<>7 => r8c3=3 => r6c3=5 =>
(8=1)r1c3-(9=1)r1c7-(9-8)r2c9 => r1c8,r2c3<>8

Can this be displayed in Eureka notation? or more simply
Back to top
View user's profile Send private message
SudoQ



Joined: 02 Aug 2011
Posts: 127
PostPosted: Sun Mar 04, 2012 12:07 am    Post subject: Reply with quote
Why not a tri-cell for a change!

Code:
r1c3=1 ->                                      =>
    =8 -> r1c8=5 -> r3c9=1                     =>
    =5 -> r6c3=3 -> r8c3=7 -> r8c9=5 -> r3c9=1 => r1c7<>1


/SudoQ
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sun Mar 04, 2012 12:49 am    Post subject: Reply with quote
Dan: This should come close to what you want. It's a network elimination made to look like a chain. It uses a lasso on cells r1c8 & r3c9. The (*) indicates where memory is used to make the []-chain work.

Code:
 +--------------------------------------------------------------+
 |  125   4     158   |  29    6     7     |  19    58    3     |
 |  27    3     78    |  29    5     1     |  4     6     89    |
 |  156   9     156   |  3     8     4     |  7     2     15    |
 |--------------------+--------------------+--------------------|
 |  8     12    4     |  5     7     6     |  19    3     129   |
 |  167   1267  9     |  8     4     3     |  5     17    126   |
 |  35    67    35    |  1     2     9     |  8     47    46    |
 |--------------------+--------------------+--------------------|
 |  9     5     2     |  7     3     8     |  6     14    14    |
 |  4     8     37    |  6     1     25    |  23    9     57    |
 |  1367  167   1367  |  4     9     25    |  23    58    578   |
 +--------------------------------------------------------------+
 # 52 eliminations remain

(8*)r1c3=[(5)r1c8=(5-1)r3c9=r1c7-(*81=5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9-r3c9=(5)r1c8]
  =>  r1c8<>8
________________________________________________________________________________________

As a network:

Code:
(5)r1c8=(5-1)r3c9=r1c7-(1=5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9-r3c9=(5)r1c8  =>  r1c8<>8
                             ||
                      -(1=8)r1c3                                             =>  r1c8<>8

Using SudoQ's Kraken Cell: r1c3=158

Code:
(8)r1c3                                             =>  r1c8<>8
(5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9-r3c9=(5)r1c8  =>  r1c8<>8
(1)r1c3-r1c7=(1=5)r3c9=(5)r1c8                      =>  r1c8<>8
Back to top
View user's profile Send private message
Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Sun Mar 04, 2012 1:42 am    Post subject: Reply with quote
Dan, I don't know if you were looking for other solutions or just an answer to your question. I certainly can't answer the question.

XY-Wing (375), pivot r8c3, flightless with transport; r1c3<>5
XY-Wing (581), pivot r1c8; r1c7<>1
Back to top
View user's profile Send private message
JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Sun Mar 04, 2012 8:18 am    Post subject: Reply with quote
Also, written as a 7-SIS AAIC or AXYChain :

8r1c3=XY Chain[(1=5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9-(5=1)r3c9]-(1=9)r1c7-(9=8)r2c9 => 8r1c3=8r2c9 => -8r2c3.r1c8
Back to top
View user's profile Send private message
arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
PostPosted: Sun Mar 04, 2012 11:18 am    Post subject: Reply with quote
Marty R. wrote:
Dan, I don't know if you were looking for other solutions or just an answer to your question. I certainly can't answer the question.

XY-Wing (375), pivot r8c3, flightless with transport; r1c3<>5
XY-Wing (581), pivot r1c8; r1c7<>1
I and others can learn from all answers. Thanks.

With the help of JC's

(8)r1c3=XY Chain[(1=5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9-(5=1)r3c9]-(1=9)r1c7-(9=8)r2c9 => r1c8<>8

I have attempted to show Marty's in Eureka notation:

(1=58)r1c3-(5=3)r6c13-(3=7)r8c3-(7=5)r8c9-(5=1)r3c9 => r1c7<>1

If this is right Marty's is much simpler.

JC and Marty you have made my day!
Back to top
View user's profile Send private message
JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Sun Mar 04, 2012 1:16 pm    Post subject: Reply with quote
arkietech wrote:
I have attempted to show Marty's in Eureka notation:

(1=[58)r1c38-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9]-(5=1)r3c9 => r1c7<>1

If this is right Marty's is much simpler.

To avoid a too condensed notation, I would have written, using [] to isolate the XY Chain ...

1r1c3=XY Chain[(5=8)r1c8-(8=5)r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9]-(5=1)r3c9 => -1r1c7.r3c13

Best regards, JC.
Back to top
View user's profile Send private message
ronk



Joined: 07 May 2006
Posts: 398
PostPosted: Sun Mar 04, 2012 1:39 pm    Post subject: Reply with quote
arkietech wrote:
I have attempted to show Marty's in Eureka notation:

(1=58)r1c3-(5=3)r6c13-(3=7)r8c3-(7=5)r8c9-(5=1)r3c9 => r1c7<>1

If this is right Marty's is much simpler.

Without any intermediate exclusions, I don't see anything quite that simple. Using JC's notation for a kraken cell on a single line ...

(1)*r1c3=xy-chain[(5=8)r1c8-(8=5)*r1c3-(5=3)r6c3-(3=7)r8c3-(7=5)r8c9]-(5=1)r3c9 ==> (1)r1c3=(1)r3c9 ==> r1c7,r3c13<>1

The '*' highlights the usage and appearances of a tri-valued cell. Counting this as a single SIS, a 6-SIS is required compared to a 7-SIS stated elsewhere, so this could be said to be simpler.

However, Marty's two AICs with an intermediate exclusion require only seven strong inferences, four for the transported xy-wing and three for the other xy-wing. IMO it's considerably easier to understand his two xy-wings than the single AAIC written above. IOW I don't really understand the obsession to express puzzle solutions as a single step.
Back to top
View user's profile Send private message
arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
PostPosted: Sun Mar 04, 2012 2:33 pm    Post subject: Reply with quote
ronk wrote:
IOW I don't really understand the obsession to express puzzle solutions as a single step.


It keeps my mind from growing stale. Very Happy

and besides it is fun.
Back to top
View user's profile Send private message
JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Sun Mar 04, 2012 2:40 pm    Post subject: Reply with quote
ronk wrote:
... I don't really understand the obsession to express puzzle solutions as a single step.

In this particular puzzle, it is true that it is very hard to "beat" a 2 Wings (totalizing 6-SIS) solution (MW + HW or XYW) Very Happy
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