Help for biginner

sudoku4aptiva · Posted: Wed Nov 08, 2006 12:42 am Post subject: Help for biginner

I have downloaded the Simple Sudoku. I can do the basics -- up to naked/hidden pair/triple/quad.

I am doing this puzzle:

*-----------*
|...|1..|..7|
|.9.|..4|..5|
|8.2|...|1..|
|---+---+---|
|5.9|3..|...|
|.7.|.5.|.3.|
|...|..6|9.8|
|---+---+---|
|..8|...|5.2|
|1..|6..|.4.|
|9..|..8|...|
*-----------*

I111
I525
I288
I398
I419
I097
I122
I461
I698
I441

and this is as far as I go. When I press F7 for Hint; it highlights C7R5 and states "Excludes based on Locked Candidates (1).

I can't see the Locked Candidate. Would appreciate someone point me to that Locked Candidate(s) with an explanation of why that is locked.

P.S. I saw some messages include the actual puzzle [image]. How does one do that? I don't see any upload feature. Do I simply paste the image in the message?

TIA

Jean-Christophe · Posted: Wed Nov 08, 2006 10:59 am Post subject:

Locked Candidates AKA Line-Box Interactions AKA intersections. It's a basic technique.
See http://angusj.com/sudoku/hints.php
And http://www.sadmansoftware.com/sudoku/technique3.htm

To publish an image, you may use a free image hosting service like http://imageshack.us/
_________________
Jean-Christophe
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.

sudoku4aptiva · Posted: Thu Nov 09, 2006 12:42 am Post subject:

I have read the instruction (posted above) re Locked Candidates before I posted my question. The problem is I don't see the Exclusion as hinted by Simple Sudoku.

By trial and error, I find that I can exclude "2" in C1R6. but I don't understand why.

Would appreciate someone explaining it to me.

TIA

Ruud · Site Admin

Here is the LC move:

The candidates for digit 6 are locked in r5c1 and r5c3, because there are no other candidates in box 4. Digit 6 can be eliminated from r5c7.

Considering your remarks, it seems that you were looking in the wrong direction.

Ruud
_________________
Meet me at sudocue.net

sudoku4aptiva · Posted: Thu Nov 09, 2006 1:09 am Post subject:

Thanks. I was looking at R5 as a naked triple only.