The New Sudoku Players' Forum

[whitefork]

This one (sorry for the crummy formatting)
.4....6.1
6.92...43
1..74..5.
..5..231.
..4..85..
.613.....
.8..23..5
41...52.7
5.3...19.

when loaded into the program produces this message

The incoming puzzle .... is valid.
However if you use only logic and don't guess or use trial and error it is exceptionally difficult and arguably unfair.


Is it? It didn't seem all that difficult.

[ChrisT]

There's a point which I reached where the simplest ways to progress are either to make use of an XY-wing pattern or to use the "BUG" principle described on this forum. Although BUG is, in this case, very easy to spot if you know what you're looking for (all empty cells with two candidates except for one, which has three), it's not one of the standard techniques and I'm fairly sure is not included in the Pappocom software. I believe that the program will give you that message if the puzzle requires anything more "advanced" than an X-wing to solve. In this case it probably identified the XY-wing pattern needed to progress and thus labelled the puzzle "exceptionally difficult".

That would be my guess, in any case!

Chris

[Pat]

This one

Code: Select all

 . 4 . | . . . | 6 . 1
 6 . 9 | 2 . . | . 4 3
 1 . . | 7 4 . | . 5 .
-------+-------+------
 . . 5 | . . 2 | 3 1 .
 . . 4 | . . 8 | 5 . .
 . 6 1 | 3 . . | . . .
-------+-------+------
 . 8 . | . 2 3 | . . 5
 4 1 . | . . 5 | 2 . 7
 5 . 3 | . . . | 1 9 .

when loaded into the program produces this message

The incoming puzzle .... is valid.
However if you use only logic and don't guess or use trial and error it is exceptionally difficult and arguably unfair.

Is it? It didn't seem all that difficult.

hi whitefork,

i suspect that the puzzle which you posted
is probably not the easy puzzle which you solved

- Pat

[whitefork]

??

that is the one I solved. Got the paper right here.

[Animator]

that is the one I solved. Got the paper right here.

Are you sure that there is no clue in: r1c3 and r6c7?

Update: There is indeed no clue in r1c3 or r6c7. I verified it by downloading the PDF of the paper. The puzzle of January 12 might be really close to being a symmetric puzzle but the other ones aren't (for example the one from January 11).

[Pat]

that is the one I solved.

i'm sorry, whitefork!!

it did seem like a good guess -
you had said:

It didn't seem all that difficult

again, i apologize!
~ Pat