Help wanted.

Advanced methods and approaches for solving Sudoku puzzles

Help wanted.

Postby sweetbix » Sat Dec 10, 2005 12:19 pm

Hi, could someone please give me a tip.

This is the puzzle

...5.28.9
.3...8.2.
.9..1....
1.3......
.6.....9.
......5.1
....3..8.
.1.7...6.
4.29.6...

This is where I'm stuck

67 4 1 5 67 2 8 3 9
567 3 567 46 9 8 1 2 467
2 9 8 346 1 37 467 5 467

1 5 3 468 2467 9 26 47 268
78 6 47 1 247 5 23 9 238
789 2 479 3468 467 37 5 47 1

569 7 569 2 3 1 8 45
3 1 59 7 8 4 29 6 25
4 8 2 9 5 6 37 1 37

Cheers.
sweetbix
 
Posts: 58
Joined: 10 December 2005

Postby Shazbot » Sat Dec 10, 2005 12:26 pm

Code: Select all
 *-----------*
 |...|5.2|8.9|
 |.3.|..8|.2.|
 |.9.|.1.|...|
 |---+---+---|
 |1.3|...|...|
 |.6.|...|.9.|
 |...|...|5.1|
 |---+---+---|
 |...|.3.|.8.|
 |.1.|7..|.6.|
 |4.2|9.6|...|
 *-----------*

 
 *-----------------------------------------------------------------------*
 | 67     47     1467   | 5        467      2     | 8      1347   9      |
 | 567    3      14567  | 46       4679     8     | 1467   2      4567   |
 | 25678  9      45678  | 346      1        347   | 3467   3457   34567  |
 |----------------------+-------------------------+----------------------|
 | 1      24578  3      | 2468     2456789  4579  | 2467   47     24678  |
 | 2578   6      4578   | 12348    24578    13457 | 2347   9      23478  |
 | 2789   2478   4789   | 23468    246789   3479  | 5      347    1      |
 |----------------------+-------------------------+----------------------|
 | 5679   57     5679   | 124      3        145   | 12479  8      2457   |
 | 3589   1      589    | 7        2458     45    | 2349   6      2345   |
 | 4      578    2      | 9        58       6     | 137    1357   357    |
 *-----------------------------------------------------------------------*


You've placed TWO 1s in box 9. The one in r7c7 is not valid as 1s in row 9 are locked to box 9.

I found this puzzle pretty easy using lots of hidden/naked singles, a few locked candidates and naked pairs, and an xwing (maybe not necessary). Find what you've done wrong (or start again) and you might complete it without too much hassle.
Last edited by Shazbot on Sat Dec 10, 2005 8:40 am, edited 1 time in total.
Shazbot
 
Posts: 220
Joined: 24 September 2005

Re: Help wanted.

Postby ronk » Sat Dec 10, 2005 12:34 pm

sweetbix wrote:This is where I'm stuck
Code: Select all
  67     4     1     5     67    2     8     3     9   
  567    3     567   46    9     8     1     2     467 
  2      9     8     346   1     37    467   5     467   
 
  1      5     3     468   2467  9     26    47    268 
  78     6     47    1     247   5     23    9     238   
  789    2     479   3468  467   37    5     47    1     
 
  569    7     569   2     3     1     49    8     45   
  3      1     59    7     8     4     29    6     25   
  4      8     2     9     5     6     37    1     37

Look for a locked candidate (box 2, col 4).

Your grid is missing the candidates 49 for r7c7.
ronk
2012 Supporter
 
Posts: 4764
Joined: 02 November 2005
Location: Southeastern USA

Postby sweetbix » Sat Dec 10, 2005 1:13 pm

Sorry, my mistake. I missed typing in the numbers 49 for that cell.

Thanks for the tip, ronk, I get it now.
sweetbix
 
Posts: 58
Joined: 10 December 2005


Return to Advanced solving techniques