Puzzle 12: Total Yajilin
This is a Yajilin puzzle with a small twist. Each clue number is now equal the total number of black squares in the same row and column as that clue number (this means I don’t have to draw any arrows, yay!).
Notes: This is pretty much MellowMelon’s Indirect Yajilin, but I figured that it wouldn’t exactly be accurate to call this puzzle Indirect when it only uses clues of this one type. And, of course, putting grey plus signs in the cells would be a very difficult task for me.
Also, on a more personal note, I haven’t constructed anything in the past month mainly because of college apps. However, I submitted my early action applications to MIT and Caltech yesterday, which means more time for puzzles! 😀 Though I suppose it would be a good idea to force myself to construct at a rate of two puzzles per week or something so there aren’t any huge time gaps between postings.
anderson's Puzzle Blog 
I take it the logic that there had to be exactly 3 black squares in the pair of rows/columns going in each direction from the pair of 6s was intended. Very nice.
MellowMelon
November 1, 2011 at 9:09 pm
Well, this is amusing.
I actually did not think of that logic, and my original path involved showing that the lower-left 6 couldn’t have 2 black squares to its left. This was the one step that I didn’t like very much, because it involves a little trial and error (even though it’s looking only one step ahead).
Now that you tell me that, though, I see that step can be avoided completely. So I guess I got very lucky with the pair of 6s working out that way. 🙂
qzqxq
November 1, 2011 at 9:50 pm
I don’t think it’s a problem to call this Indirect Yajilin. Melon’s puzzles 65 and 189 also use just one clue type: http://mellowmelon.wordpress.com/category/puzzle-types/yajilin/indirect-yajilin/
There’s also http://mathgrant.blogspot.com/2010/11/monday-mutant-50-straight-and-arrow.html , even though Grant has compulsively not called it “Yajilin.” But it’s still worth pointing out since the puzzle from the next week, http://mathgrant.blogspot.com/2010/11/monday-mutant-51-straight-and-arrow.html , uses a colorless notation. I don’t think he’d mind you using it.
Bryce Herdt
November 2, 2011 at 10:14 pm
Ah, okay. Thanks for those links. + and X are certainly much easier to use!
I did know that some of Melon’s puzzles used one clue type, but I figured that this particular one isn’t exactly “indirect”. The red X clues and the “determine the direction” clues are certainly indirect, but I feel the + clues are more direct in that they give you exact information about the number of black squares in a subset of squares in the grid. This is all semantics, though, and I just hope that you enjoyed the puzzle. 🙂
qzqxq
November 3, 2011 at 2:42 am
Yes! Yes I did. Shouldn’t have forgotten to put that in.
Bryce Herdt
November 3, 2011 at 4:19 am
Weird. How is this listed under “Yajilin” but not “Puzzles!”?
Bryce Herdt
November 9, 2011 at 11:36 pm
That’s quite strange. “Puzzles!” even has a (13) next to it, so I’m really not sure. I guess I’ll just add this post directly to the Puzzles! category. Thanks for pointing it out!
qzqxq
November 13, 2011 at 12:51 am