The New Sudoku Players' Forum

[dah069]

Can anyone help me with what I should do next?

Code: Select all

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



Thanks,
David

[saulysw]

Hmmmmm

There are quite a lot of hidden and naked pairs in this one.

My suggestion? Enter the puzzle into Sudoku-san and use the "suggest a move" feature. It explains things pretty well. it gets you a bit further, but it looks to be quite a hard puzzle....

- Saul

[vink]

r8c8 can be 6 or 9.

i tried 9 and after a while i had two 6 in column 3, so...

r8c8 must be 6.


this allowed me to complete the scheme through very easy steps.
here it is

[dah069]

Thanks Saul.
I took your advice and went to sudoku-san and it said that although the puzzle had only one solution, it couldn't be solved using the logical solver! And I got the puzzle from a tutorial re X-wings - how frustrating!!

Thanks for your help - that site is very good!

David

[angusj]

I took your advice and went to sudoku-san and it said that although the puzzle had only one solution, it couldn't be solved using the logical solver! And I got the puzzle from a tutorial re X-wings - how frustrating!!

Well, it can be solved with logic including an x-wing.

Hints:
1. Naked quad in Box6 (or hidden pair)
2. X-wing on 9s.

[Wolfgang]

1. Naked quad in Box6 (or hidden pair)
2. X-wing on 9s.

You mean box7 ? But also after that i cannot finish it with simple techniques. Did i overlook something ?

[angusj]

You mean box7 ? But also after that i cannot finish it with simple techniques. Did i overlook something ?

Yes, quite right, I did mean box7.

1. Naked quad in Box 7 (or hidden pair)
2. X-wing on 9s.
3. Naked triple row 9.

[Wolfgang]

Ah yes, thanks (dont need the quad)

[alastairchisholm]

Hi all,

As the owner of Sudoku-san, I spent much of yesterday scratching my head trying to work out why the Assistant couldn't solve this puzzle. Working off the clue of 'X-wing on 9s' I pored over the grid (having solved it as far as the Assistant could) looking for where it could be...

...And in the end, realised that the Assistant had found the x-wing, but was then missing a blindingly obvious chain of three along the bottom row. D'oh!

All fixed now, honour partially restored (though pretty embarressed about the bug)

cheers,
Alastair
www.sudoku-san.com

[Jeff]

Gee, your name is pretty long. Alastairchisholm, where are your from?

[alastairchisholm]

Hi Jeff,

I'm from Scotland... and the name itself is "Alastair Chisholm" - I just found that after a while I was fed up spending twenty minutes on every bullitin board site trying to find a name that hadn't been used :-)

cheers,
Alastair
www.sudoku-san.com