Support charity, get puzzles!
Patron Puzzles for Philanthropy

Monday Mutant 65: Cross the Streams

Shade in some cells black such that the black cells are all connected to each other through their edges, and no 2x2 cell area within the grid contains all black cells. Numbers to the left of a row or above a column represent the groups of consecutive black cells which are in that row or column. For example, a clue of "3" means the row or column has three consecutive black cells, and a clue of "3 1" means that the row or column has a group of three consecutive black cells followed by a single black cell, separated by at least one white cell. A question mark (?) represents a group of consecutive black cells whose size is unknown; an asterisk (*) represents any number of unknown groups of black cells, including none at all.
Gotta love Cross the Streams.

6 comments

Jonah said...

I do indeed love Cross the Streams, but I had no idea that it loved me back!

Anonymous said...

Heeeeee hee hee.

Love Cross The Streams, but wonder why it's always a Mutant puzzle when it's far closer to being "invented or popularized" by Nikoli than, say, the Eliza Pseudonym Of Puzzlania puzzles (which, apropos of nothing, would be much more fun with some form of grid -- either the full ticks-and-crosses lattice or the small rubric list form).

Grant Fikes said...

Anonymous: Nikoli does regularly print logic problems of the Eliza Pseudonym format, albeit in Japanese, in volumes of Puzzle Communication Nikoli and Puzzle the Giants. I'd say Nikoli at least moderately "popularized" these puzzles, in Japan if not worldwide. By my definition, a "Monday Mutant" puzzle is pretty much anything which isn't a Nikoli standard. This means:

Eliza Pseudonym of Puzzlania-style puzzles are a Nikoli standard, so they'll never be Monday Mutants. (I have published them as "puzzles" both before and after the introduction of "Monday Mutants".)
Puzzles which Nikoli doesn't publish, such as Cross the Streams, are not Nikoli standards, but Monday Mutants.
Unusual variations of Nikoli standards, such as Sudoku puzzles where two adjacent cells contain consecutive numbers if and only if they have a dot between them, are also not Nikoli standards, but Monday Mutants.

Your comment regarding grids in Eliza Pseudonym of Puzzlania is more valid, since Nikoli does, in fact, publish its logic problems with these grids when applicable (which is 90% of the time). I like the compactness of plain text and intend to keep it that way for now. However, as with the diagonal lines added to Proof of Quilt, if enough regular solvers agree with you to persuade me, a change could happen. :)

[Special thanks to David Millar who helped me ensure that this response was at most 50% less succinct than it needed to be.]

Anonymous said...

Yeah, the "popularized in Japan" is a good way of getting around the Mutant restriction for Eliza Pseudonym. I was thinking in terms of the Western world, where Dell, Penny Press, and the British constructors are definitely more responsible for popularizing the genre. (Though the former two aren't exactly the sort of links you'd want to advertise, to be honest.)

I'm torn on the grids, though -- if you're a print-out solver, I think it'd be just as easy with or without the grids, but if you're a copy-into-Paint-or-equivalent solver (as I'd guess the majority of visitors here are based on the Proof Of Quilt change), the grid would definitely help.

Grant Fikes said...

Anonymous: I am mildly familiar with PennyDell's logic problems, but not so much with the British logic problem scene. Actually, I have a volume of Penny Press's Original Logic Problems: British Edition!. They definitely have a sense of humor which many American logic problems lack, and I like that. As pointed out on that page, they are also easier than the other Logic Problems PennyDell publishes; all of them require the solver to find one-to-one match-ups for elements in equally-sized categories where all of the elements are known (for example, four motor racers with four makes of car with four unfortunate things that can happen to race cars with four numbers of laps that the cars completed before that happened). In contrast, Nikoli has published a logic problem which, despite my illiteracy in Japanese, seems to ask the solver to determine the scores of several baseball games, including how many runs each team scored in each inning. It's not known beforehand what the 18 numbers in a score are, and numbers are allowed to repeat.

I don't know whether solvers who use image-editing software make up a majority of my audience; indeed, two of my regular solvers always submit Eliza Pseudonym of Puzzlania solutions as text.

ksun48 said...

oh we can submit solutions regularly? that's fun

Blog Archive