Puzzle Description:

#1: m2 (mercymercy) on Dec 26, 2008

rotund

Yup, well fed.

Has it lost a leg?

i found myself in a place where i had to make an educated guess to continue. i used the symetry as my guide.

I also had to use the symetry to complete it. Maybe the missing leg is to give it only one solution?

had to guess symmetry.

There are a few cells you can fill in or dot with smile, edge, and two-way logic, but it seems symmetry is the best way to go to get to a solution.

Found to require some guessing by jan.

The only guess needed is to assume symmetry on the 5 in row 14.

I've been wracking my brain to see if there's a way around it using xXxtreme logic. I've gotten several pixels in places that aren't obvious. A nice example is that c4r6 & c12r6 must be white because of crossing 2 clues.(C4&6 vs r7&8 and c10&12 vr7&8) Those 2s mean that there must be 2x2 squares of black, and those two pixels would be white no matter where the black squares overlap the already black pixels.

Also, [c4r10 to c6r11] and [c10r10 to c12r11] must also contain black squares. This is using a bit of information that we don't normally use: Normally we would not be able to tell whether these areas would have a 2x2 square or a "staircase" in them. However, the only staircase possible would be :

+-+-+-+
|X|X| | 
+-+-+-+
| |X|X| 
+-+-+-+

OR

 
+-+-+-+
| |X|X| 
+-+-+-+
|x|X| | 
+-+-+-+

HOWEVER, since we know the puzzle has a unique solution, neither of those are possible as they are interchangeable clue-wise.

 

However, I'm stuck about 3/4 done. http://www.postimage.org/image.php?v=TsTbetr

I did it without guessing. When I got stuck, I started narrowing down possibilities for the 5 in R14. I could rule out its going back as far as C4 or C5; ditto for C11 and C12. After that, it was fine.

It looks someone already stepped on it!

(I fixed the formatting in Joe's comment #9)

i agree with gator...i used edge, one (each side) instance of two-way logic (with minimal look-ahead) and smile logic (primarily one up top and then once down low once you get enough other things filled in to narrow in on that 5 in R14). no symmetry logic was necessary (though would have made solving easier)...personally, i consider this one solvable without guessing.

David - how did you go forward from my posted image?

And the status has changed from "(requires some guessing)" to no warning. Maybe inadvertently when Jan edited my comment?

I guess it got through the first time, 504 - gateway error notwithstanding...

i don't remember my path from back then, but looking now...let's see, the best i can do:

whether C3R11 or C3R13 is black, the resulting dot(s) force C2R6 will be black.

lookahead alert: whether C1R11 or C1R13 is black, C2R13 is a dot.

IEL (?) blacks C4R13

same stuff other side?

Goto next topic

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