## What next?

Advanced methods and approaches for solving Sudoku puzzles

### What next?

Hi,
I'm having problem with the following puzzle. I have solved it using trial and error, but I'm frustrated that I can't see the logic that will help me get beyond this point. Anyway, here is the puzzle:

{6}{8}{2} {7}{1}{9} {5}{3}{4}
{7}{5}{3} {268}{24}{48} {9}{168}{168}
{9}{1}{4} {68}{5}{3} {2}{7}{68}

{8}{34}{16} {5}{7}{2} {46}{9}{136}
{25}{34}{67} {18}{9}{18} {467}{56}{2356}
{25}{9}{17} {4}{3}{6} {78}{158}{1258}

{3}{7}{8} {9}{46}{45} {1}{2}{56}
{4}{6}{9} {12}{28}{15} {3}{58}{7}
{1}{2}{5} {3}{68}{7} {68}{4}{9}

jenn

Posts: 1
Joined: 12 October 2005

Let me cheat like I always do in these situations
and use Simple Sudoku, which shows your puzzle like this:

Code: Select all
` *-----------------------------------------------------------* | 6     8     2     | 7     1     9     | 5     3     4     | | 7     5     3     | 268   248   48    | 9     168   168   | | 9     1     4     | 68    5     3     | 2     7     68    | |-------------------+-------------------+-------------------| | 8     34    16    | 5     7     2     | 46    9     136   | | 25    34    67    | 18    9     18    | 467   56    2356  | | 25    9     17    | 4     3     6     | 78    158   1258  | |-------------------+-------------------+-------------------| | 3     7     8     | 9     46    45    | 1     2     56    | | 4     6     9     | 128   28    158   | 3     58    7     | | 1     2     5     | 3     68    7     | 68    4     9     | *-----------------------------------------------------------*`

According to SS, you'll need to use the XY-Wing pattern
3 times (!) to break this puzzle. (Search columns 8 and 9
to find the key 3 cells in the 1st XY-Wing.) Also look for
locked candidates after the 1st elimination based on the
1st XY-Wing.

Just in case you are unfamiliar with this pattern, it
is described here.

Nick67

Posts: 113
Joined: 24 August 2007

Nick, did you have to manually put that puzzle into SS or can you copy brackets ‘n all?
emm

Posts: 987
Joined: 02 July 2005

Hi em,

I thought I might be able to paste the puzzle, even
with the brackets .... but alas, no. I just checked now,
and SS doesn't seem to accept any format that shows candidates.
a text file, is posted, it can be copied from the post and
pasted directly into SS.]

So, just in case anyone wants to paste this puzzle into SS,
here it is in SS format:

Code: Select all
` *-----------* |682|719|534| |753|...|9..| |914|.53|27.| |---+---+---| |8..|572|.9.| |...|.9.|...| |.9.|436|...| |---+---+---| |378|9..|12.| |469|...|3.7| |125|3.7|.49| *-----------*`

... but you will lose some candidate info that Jenn had

(BTW, off-topic, but that was a fine Sudoku poem you wrote
the other day! I was surprised you didn't get more feedback ...)
Last edited by Nick67 on Thu Oct 13, 2005 1:34 pm, edited 1 time in total.
Nick67

Posts: 113
Joined: 24 August 2007

Thanks Nick, I rather liked it myself but feedback is nice.

PS : r.e.s. gave me the idea and Paul gave me the romantic inspiration!
emm

Posts: 987
Joined: 02 July 2005