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 

Triple shoot trick to solve diabolical puzzle

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Solving techniques, and terminology
View previous topic :: View next topic  
Author Message
mahadevan



Joined: 18 Nov 2009
Posts: 6
Location: india bangalore

PostPosted: Wed Nov 18, 2009 3:44 am    Post subject: Triple shoot trick to solve diabolical puzzle Reply with quote

Hi all,
I really need some inputs on this technique.

http://picasaweb.google.com/tajomaysudoku/Sudoku#5405276178561943026

Experience shows that in Diabolical puzzle triplets are difficult to spot. Hence the Arrow shoot / Triple shoot
trick has been devised and experimented.

Authenticity of this trick has to be explored through other puzzles.

After fixing the straight numbers in all nonets, some twins in the same nonets or triplets in two regions or cells triplet in two cells
were pencilled.

Though the author in the above book suggested to apply Adriane's trick i.e.
try with one approach and in case of failure, try the other route.

But a successful attempt was made to solve this puzzle with a new approach i.e. "Arrow shoot".

The purpose is to fix the 3 and 5 in Nonet 1 i.e. either 3 left or right.

Scrutinise the Nonet 7 wher 3s are in two rows i.e. R7 and R8. This nonet has 3s in a row (R8) and two 3s in R7
Irrespective of the row the 3s in this nonet have formed an arrow i.e. three 3s in a row and 3 in the middle of R7.
With the arrow like 3s if the journey starts to fix the 3 in Nonet, the journey ends in nonet 1 - R3 - C2.


Hence R3 C3 becomes 5.
(Of course 35 in Nonet 4 was written after resolving Nonet 1 and 7

After this the puzzle has an easy flow and can be completed in the normal way.

Anyone can suggest a still better method.

Definition of some terminologies
Nonet : a Region consisting of 9 cells

R = Row
C = Column

Regards,
Mahadevan
Back to top
View user's profile Send private message
storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Wed Nov 18, 2009 6:08 am    Post subject: Reply with quote

the puzzle has 195 solutions.
Back to top
View user's profile Send private message
Mogulmeister



Joined: 03 May 2007
Posts: 695

PostPosted: Wed Nov 18, 2009 8:06 am    Post subject: Reply with quote

Mahadevan,

What I believe you have there is an early Michael Mepham when sudokus with multiple solutions were still being set as puzzles. The other giveaway is the use of Ariadne's thread as a technique - which is essentially a trial and error technique that he championed early in the evolution of this game (or sickness as Marty calls it).

The majority of puzzle setters these days set sudokus to have one solution and -although still contentious- many purists look for logical or a priori solve paths rather than guesswork to complete them.

Perhaps we could see the arrow shoot on some other diabolical or Extreme puzzles ?
Back to top
View user's profile Send private message
daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Wed Nov 18, 2009 10:52 am    Post subject: Reply with quote

If you examine the PM grid next to the puzzle, you'll see that given r2c5=2 has been converted into solved cell r2c6=2. You need to find another source for puzzles.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Solving techniques, and terminology 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