Puzzle Description:

sorry :)

#1: Gator (Gator) on Jun 29, 2010 [HINT]

I've tried to get this one to solve, but I'm thinking this one requires looking ahead a lot of moves to solve. I have used edge logic, two-way logic, and affirmation logic to get about half way done, but now I am stuck.

New version published by sensei69.

New version published by sensei69.

sorry Gator, i re-worked it a bit

i agree with gator

I'm still having trouble getting it to solve. Sorry... :(

i don't understand this Gator, i just solved it again!
did you start with edge logic for the 10?

This is what I have done.

The initial line logic gets me 25 blacks and 12 dots.

I then use edge logic on the 10 clue on row 20 and I place 8 cells in columns 7-14. More line logic.

I then use edge logic on the 5 clue in column 1 and I can place 4 cells in rows 6-9. More line logic.

I then use two-way logic with the 5 clue know that it can either be finished with R5C1 or R10C1. With the 4 clues on both of those rows, we know that columns 2 and 3 will be satisfied by R5C2 and R5C3 or R10C2 and R10C2. So we can dot most of columns 2 and 3. More line logic.

Now looking at row 1, I can use edge logic to make R1C9 and R1C10 dots. More line logic.

Next looking at the left 3 clue in row 1, it will have to either be in R1C11 or R1C14. In either case, row 2 will be satisfied, so we can dot most of row 2. More line logic.

I then used internal edge logic with the 4 clue in row 7 to see that R7C6-R7C10 had to be dots.

Next I used internal edge logic on the 3 clue in row 5 to see that R5C10 had to be a dot.

Next I used edge logic on the 2 clue in column 10 to see that R3C10 and R4C10 had to be dots. More line logic.

I also just noticed that I could have continued the internal edge logic in row 7 to make R7C11-R7C14 dots. A little more line logic.

And I am stuck.

http://i220.photobucket.com/albums/dd289/Gator621/WPBN-ItsTimeTo.jpg

i had about the same, and finally resorted to multi-step extended edge logic (also known as trial and error) to get this to solve

okay gator .... its your decision... but
why can't one use smile logic on row 20?

Because that assumes a symmetry that is not guaranteed. Smile logic is also constrained in such a fashion that there is only one possible way fill in a set of cells. Smile logic will also show a contradiction on a different row(edge logic) if you try to place the cells too far left or right. In your case, no contradiction exists on affected rows. So we are left with 3 different ways that row 20 could be filled in, all of which do not cause a contradiction when looking at most 2 moves ahead.

New version published by sensei69.

New version published by sensei69.

solvable now woo

Thank goodness I wasn't the only one! Gonna go back and try it again.

okay ...fatter clock now .... lol

Found to be logically solvable by Gator.

Thanks Tom. Edge logic on just the 12 required now.

I'm glad I didn't try the earlier ones! This one was enough of a challenge. Good job

Nice puzzle. I appreciate your going back and fixing it, Tom. This is a good lesson in making a puzzle logical. It's very tempting to use visual logic. It's a fun mental exercise to separate what the visual part of your brain says it should be from the logical part of your brain that wants to prove that's the only possible placement.

Found to be logically solvable by jan.

Looks like one of Salvador's clocks. :)

More than 8 years later, I agree with Kristen.

Of course you do! I have the best ideas! ;)

you surreally do!

Goto next topic

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