Next step only

Post the puzzle or solving technique that's causing you trouble and someone will help

Next step only

Postby einstr » Mon May 22, 2006 9:21 pm

Hi all,
I have gotten as far as below and I can't seem to figure out the next step. Any help would be appreciated. I am not looking for a solution but just how to go to the next step and how did you find it? Much appreciated.
Thanks.
|--------------------|
|1 - - | - - -| 7 - - |
|9 4 - |- 5 -| 2 6 - |
|3 - - |- - 4| - 8 - |
|---------------- ---|
|- 1 9 | - - -| - 5 7|
| - 5 3| - 7 -| 9 1 -|
| - 7 - | - - -| 8 2 -|
|--------------------|
| - - - | 6 - -| - - - |
| - 3 1| - 4 -| - 9 2|
| - - 2| - - -| - - 8|
|---------------------|
einstr
 
Posts: 2
Joined: 22 May 2006

Postby underquark » Mon May 22, 2006 11:28 pm

Row 6 - columns 1 and 3 (r6c1 and r6c3) can each only either be 4 or 6 and are mutually exclusive i.e. a "naked pair". Since one of them is 4 and the other is 6 (although we don't know which is which yet) this means that 4 and 6 can't lie anywhere else in that row or in any of the other cells in that box. Looking along to the end of Row 6 we see that r6c9 could have been either 3, 4 or 6. Since we know that it can't be 4 or 6, then it must be 3.
underquark
 
Posts: 299
Joined: 06 September 2005

Postby einstr » Tue May 23, 2006 1:02 am

Thanks for the tip. I just started these and get the easy and most of the mediums, but I am unfamiliar with the terms used. now i know about naked pairs. Anywhere to find out about more approaches?
einstr
 
Posts: 2
Joined: 22 May 2006

Postby TKiel » Tue May 23, 2006 1:37 am

Lots of info on techniques in the 'Advanced solving techniques' forum. You could also check out these links:

www.sadmansoftware.com/sudoku/techniques.htm

www.angusj.com/sudoku/hints.php

www.scanraid.com/BasicStrategies.htm

Tracy
TKiel
 
Posts: 209
Joined: 05 January 2006

Next step only

Postby Cec » Tue May 23, 2006 8:57 am

einstr wrote:"... I just started these ......I am unfamiliar with the terms used......... Anywhere to find out about more approaches?"

Hi einstr,
To complement the above help, you could also click on Here which describes the procedures for posting puzzles and the standard terminology .

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005

Postby mike34230 » Sat May 24, 2008 11:48 pm

Interesting... my next step was to eliminate the 6 as a candidate for row 4, column 7... since column 7 can only have a 6 in box 9
mike34230
 
Posts: 3
Joined: 24 May 2008

Postby mike34230 » Sat May 24, 2008 11:55 pm

mike34230 wrote:Interesting... my next step was to eliminate the 6 as a candidate for row 4, column 7... since column 7 can only have a 6 in box 9


oops... I posted too quickly... that didn't even help me... immediately after that I found 3 naked pairs and the puzzle was over... sorry!
mike34230
 
Posts: 3
Joined: 24 May 2008


Return to Help with puzzles and solving techniques

cron