Puzzle Description Suppressed:Click below to view spoilers

#1: Robyn Broyles (ginkgo100) on Aug 17, 2009

The title refers both to the subject matter and the difficulty of the puzzle. My first hint tells how to get past all the tricky parts—the ones the "helper" function could not figure out.

1. Upper right corner
2. R30C10 has to be white
3. R32 C9,10,11: Can't all be black
4. R26C12 has to be white

EDIT: Got ahead of myself. Here's one more tricky spot:

5. If R35C9 is black, then the block of 5 is directly above it. And that's where the block of 4 in R31 must be, too. But that's impossible per C6. So R35C9 must be white.

I know this may push the edges of logic v. guessing for some people. I can see it clearly in my mind without making any marks on the board, so I consider it logic.

If you found something I missed, please post it!

Comment Suppressed:Click below to view spoilers

I got to a point where I got stuck. I looked at your hints, but they didn't help.

#1... What about the upper right corner?
#2... I already had that.
#3... Yes, that's true, but the 4 could still go on either
side of that area. Or the 1 in that row could go there.
#4... Why? It could be either on my puzzle.
#5... When I tried to place a black in R35 C9, yes, the 5 has
to go above that. Yes, the 4 in R31 has to go in that
same area, but it didn't violate C6 at all.

Maybe I missed something.


I tried to send a picture of the point I was at when I got stuck. It didn't work. I tried to save the page and copy/paste it in here, too. Didn't work. Any ideas on how to do post the picture or the link to post it here?

1. Upper right corner is some edge logic. Sorry for the lack of details. The blocks of 5 and 7 must be on the left side of the puzzle, not the right.

I'll try to take a look at the other problems... I certainly hope I did not make a mistake in my test-solves...

The key to this puzzle is rows 32 and 33, and the fact that the bottom clue in columns 1-17 is 1.

For #3: What I meant is that at least 2 of those 3 must be white. The most conservative assumption is that the two on the right are white; which means R35 C10,11 must be white. Therefore R32 C10,11 actually *are* white. That lets you place R26C10 (black), R26C12 (white), and R22C12 (black).

This time when I did steps 1-4, I didn't need step 5 after all (twice in a row, actually). R35 C6 and C10 are white, so the three squares between them are as well. That lets you place several more white squares in R32. From there you should be able to finish solving it.

Does this help? I'm going to look at your picture now, assuming the link works.

Sure, it makes sense, but it still comes down to the fact that you "arbitrarily" chose (or "conservatively assumed") that the two spaces on the right (R32, C's 10,11) were white. The problem lies in the fact that there is no way you can know which of those 3 spaces, or if even any at all, are black or white. Usually we at least have a reason or basis for any given choice, but not here. Yes, if you do that, then it solves fine.

I am sure there is likely a way to solve this logically, and I hope someone can point out that way, but based on the method you provided, that counts as guessing.

By the way, cute image!

Not quite sure how, but i was able to solve this one without any guessing or edge logic.

P.S. nicely done!

Somehow I find that very hard to believe. But if you did, then kudos to you. Really.

Anyone else have any thoughts on this?

Nice image! I also was able to solve this with just a minimum of lucky guessing; I started with the row of 18, and somehow it just all came together. I'm not smart enough to get as scientific about these things as some of you do! But some days my muse is with me!

Usually for edge logic/contradictions I consider looking 1 move ahead to be valid for "logically solvable". Sometimes 2 moves if it is really simple to do in your head. So I'm not certain which side of the "logically solvable" fence this falls on as I had to look 2 moves ahead several times, but I would lean towards the guessing side if I had to choose one or the other.

Tonia, ugh, it's hard for me to "write out" the logic in words too! I'd rather just do it, intuitively I guess... which is because I'm an INFP, I'm sure (re: Teresa's awesome Myers-Briggs series). But I wanted to explain this particular one.

Gator: Awww... well, I know it did push the boundary which is rather arbitrary, and slightly different to everyone. My rule of thumb is whether I can see it in my mind's eye, with short-term memory, or not. If I can't, I consider it guessing. If I can, I consider it logic.

I'll pledge not to push it so hard in the future—or, for Adam's sake, to clearly mark "iffy" puzzles as such!

It falls on the "logic" side of the boundary for me. I have used no lesser amount of "if-then" logic on some other puzzles—but it's entirely likely that that's because I was missing more obvious things.

Just to make sure I have no doubts about this, I'm going to start over and try this one again. I just have this nagging suspicion that I am missing something.

Adam, I was reconsidering your objection in comment #7. If you arbitrarily "chose" C9 as white instead, you would get the same result. I said assuming based on C10,11 was the most conservative because it results in the fewest squares marked white. The squares marked white in that scenario are marked white in ALL possible scenarios, so there is no scenario in which they can be black.

It is a 3-way variation of what Jan calls 2-way logic in the Advanced Puzzle Solving techniques.

It's hard for me to articulate exactly how this is (that pesky N in INFP again), but the "directions" my mind goes in this type of logic are very much like what's needed to solve the Fill-a-Pix puzzles by Conceptis. If this puzzle annoyed you, then those will make you rip your hair out! http://www.conceptispuzzles.com/index.aspx?uri=puzzle/fill-a-pix

Robyn - after looking at this again, I'm now on the side of logically solvable. There were a few things that I DID miss.

I would explain the C10, C11 situation as:

Consider the 4 clue in row 35. If you place it in columns 8 - 11, this will cause row 32 to be invalid as you would have to fill in R32C9, R32C10, and R32C11. So R35C11 must be a dot. If you try columns 7-10 in row 35, this will also cause row 32 to be invalid as you would have to fill in R32C9 and R32C10. So R35C10 is also a dot.

I didn't understand the hints the first time, but I think focusing on the 4 clue in row 35 and seeing what happens in row 32 is pretty easy to see (I did not see this when I worked on it yesterday).

This puzzle was difficult but slowly plodding away I managed to solve it with no guesswork, a small amount of edge logic and a lot of going round in circles.

Robyn, I love this puzzle! First of all, the subject is so endearing. Second, I like the way the image slowly (very slowly) came into view. Last of all, I enjoyed the edge logic. I have a hard time following people's hints on edge logic, and I know I could not explain how I did it, but I know it was tricky, requiring thinking ahead a few moves.

Since delving into the Myers-Briggs stuff, I have become more aware of my intuition. When I was first on this site, I used intuition a lot, and found most of the time I was right, but a few times I was wrong, and I didn't like seeing that red dot pop up. Intuition just means really good guessing. The logical part of my brain fights with the intuitive part of my brain, but I let the logic take over, because it's so much more satisfying to solve puzzles that way.

Clever title too. :-)

The best definition of intuition that I've seen is "unconscious cognition." It does not mean that intuition is illogical, but rather that you are not conscious of each individual step. The advantage is some great insights; the disadvantage is difficulty explaining the insights, as well as the chance of making an error somewhere that you aren't even aware of.

I'm glad you liked the puzzle!

Just the right amount of difficulty! Thank you!

Found to be logically solvable by Gator.

Some very tricky parts here, but I was able to solve it logically. And what a lovely image.

i agree with everything jan said plus i would add a very fun solve

i did the same as gator...watching what would happen in R32 depending on where the 4 in R35 goes. great fun.

Really enjoyed the solve. Thanks!

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