Nightmare, Jan 30, 2006

Shahrazad · Post by **Shahrazad** » Mon Jan 30, 2006 11:43 am

Brute force solving needed ???

ugh

Greetz,
Shah

Leo · Post by **Leo** » Mon Jan 30, 2006 2:53 pm

Shah, staan je solver instellingen wel goed, want bij mij geeft ie dat niet aan.

Niet dat ik hem opgelost heb hoor? Tegenwoordig kijk ik hoe ver ik kom en dan ga ik met de log verder. Kijken wat er nog te leren valt. Anders gaat er mij wat teveel tijd inzitten.

In Dutch, Leo wrote:Shah, are your solver settings correct, because with me {Sudo Cue} does not show this.

Not that I solved it. Nowadays I'll see how far I can get, and then I'll continue using the {Sudo Cue} log. To see what I can learn from it. Otherwise I spend too much time on it.

David Bryant · Post by **David Bryant** » Mon Jan 30, 2006 3:56 pm

Can someone explain what Leo said? I don't speak Dutch, and I can't read it, either.

Shah, the best I can do is concentrate on the connection between the "9"s and "5"s in this puzzle. Setting r5c9 = 9 cracks the puzzle wide open. Ruling out the possibility of a "9" at r5c1 seems to be a bit tricky, though. dcb

Leo · Post by **Leo** » Mon Jan 30, 2006 5:13 pm

Thanks for translation Ruud. I means that I was in the Dutch area.

Shahrazad · Post by **Shahrazad** » Tue Jan 31, 2006 7:54 am

My Solver settings are as below:

And the log shows this:

What gives ? what is wrong with my settings ?

Greetz
Shah

Shahrazad · Post by **Shahrazad** » Tue Jan 31, 2006 7:57 am

David Bryant wrote:Shah, the best I can do is concentrate on the connection between the "9"s and "5"s in this puzzle. Setting r5c9 = 9 cracks the puzzle wide open. Ruling out the possibility of a "9" at r5c1 seems to be a bit tricky, though. dcb

I guess that is the Brute Force step that accomplishes that

Greetz
Shah

Post by **Ruud** » Tue Jan 31, 2006 8:45 am

Brute Force is not required in my Nightmares.

Very deep logic, that's what's needed.

This Nightmare requires a step, that is not yet implemented in Sudo Cue, but would have been caught by the template check, which you disabled, Shah.

It goes like this:

I've used 3 different colors for the candidates in row 9. The 3 colors are green, yellow and blue. The 2 red colored candidates have to go in each of the 3 cases. So, R1C2 is forced under all circumstances.

Well, I never claimed they would be easy, did I?

Ruud.

lac · Post by **lac** » Tue Jan 31, 2006 9:47 am

I don't see how you got to the point of knowing there were 2 red
coloured candidates in row 1.

For what it is worth, I was trying to proove that c5r7 was 4 or 7, but
after hours of this I couldn't. I ended up proving that c1r9 could not
be 6. This frustratingly did not give me any other solved cells but
itself. However, I then proved that c1r8 could not be 6 either, which
solved things. But while I thought I had heuristic for determining
which cells are best to attack, it wouldn't have suggested that one.

Laura

Post by **Ruud** » Tue Jan 31, 2006 1:40 pm

lac wrote:I don't see how you got to the point of knowing there were 2 red
coloured candidates in row 1.

I knew because Sudo Cue told me there was a template elimination, which eliminated 5 candidates in a single step. All I had to do is figure out why this was the case. It did take me some time to figure this one out.

Ruud.

Shahrazad · Post by **Shahrazad** » Tue Jan 31, 2006 3:05 pm

This is getting way beyond my limited capabilities

I guess the Nightmares have outgrown me now.

These techniques are fine to use in computerprograms, but my brains aren't built for that. I can't make them, plain and simple.

Also, it's taking me too much time to attempt to solve them, and I can't neglect my work and get fired

I guess, I have to leave it to the pro's

Cya around all

Shah

David Bryant · Post by **David Bryant** » Tue Jan 31, 2006 8:42 pm

Laura wrote:I don't see how you got to the point of knowing there were 2 red coloured candidates in row 1.

I have to admit I didn't spot this right at first, but now that Ruud has pointed it out I think it's pretty slick.
A new kind of formation! Thanks, Ruud!

There are only three places for a "7" in row 1. There are only two places for a "7" in row 5. There are only
three places for a "7" in row 9. And there are only two places for a "7" in column 2.

The way the possible "7"s line up in rows 1, 5, & 9 almost make a "swordfish" pattern, but not quite
(r1c2 across from r9c3). The neat thing is, no matter where the "7" appears in row 9, there must be a "7" at r1c2.

It's not a "double-implication chain" -- it's a "triple-implication chain" of sorts. Beautiful! dcb

lac · Post by **lac** » Wed Feb 01, 2006 1:22 am

It is rather beautiful at that. Thank you.

Laura

SudoCue Users

Nightmare, Jan 30, 2006

Nightmare, Jan 30, 2006

What's that, Leo?

Re: What's that, Leo?

2 red coloured candidates?

Ruud's "Template" idea is really pretty neat!

Beautiful