Masyu (Hex) by Serkan Yürekli
or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)
Theme: Clue symmetry and logic
Author/Opus: This is the 69th puzzle from our contributing puzzlemaster Serkan Yürekli.
Rules: Variation of Masyu. Draw a single, non-intersecting loop that passes through all circled cells. The loop can only make 120 degree turns. The loop must go straight through the cells with white circles, with a 120 degree turn in at least one of the cells immediately before/after each white circle. The loop must make a 120 degree turn in all the black circles, but must go straight in both cells immediately before/after each black circle.
Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.
Time Standards (highlight to view): Grandmaster = 7:00, Master = 10:45, Expert = 21:30
Solution: PDF
Note: Follow this link for other Masyu variations and this link for classic Masyu. If you are new to this puzzle type, here are our easiest Masyu to get started on.
Phew! That was good and tough. I don’t know if hexagonal Masyu is always this difficult, (there are a lot more options to consider than in the square-cells case), or if it was just this particular puzzle. But thanks for the challenge!
I would like to see a similar puzzle but allowing 60-degree bends. Or is it too hard to make a non-trivial puzzle that way?
Right, mostly hex grids have much more possibilities than squares ones. But I think it doesn’t mean hex grid puzzles always are harder than squares. So this puzzle could be easier if I gave more clues. I mean if the Hex Masyu has a 60-degree bends rule or not, it is possible to make easier puzzles in both ways. I’ll try to prepare easier Hex Masyu with allowing 60-degree bends.
I’ve always found the 120 degree turn to very restrictive in hex grids. Parallel touching line segments can never directly join, which forces the loop to go on a long path to just make a seemingly simple connection. I think loops on the gridlines are usually better for hex grids.
Yeah, it’s not the fault of the puzzle construction, but I agree that the 120-degree turn rule made this puzzle the least satisfying translation to a hex grid of this week’s puzzle, because of the constraints it placed on the path. (Whereas I quite liked Serkan’s “Magic Fence” hex slitherlink variant that patrons received, which had its path on the gridlines.)
Just wanted to say that I’ve been loving this week’s theme, and this puzzle in particular (partly it’s because I work with hex grids regularly at my job)!
Toughest of all 2015 puzzles so far…took me abt 3 hrs to solve…
I got confused for a bit about what “120 degree turns” means; I think of these as 60 degree turns as I imagine walking along the path. I see other people using “bends” and that would lead to the same confusion in me, so I don’t know what the best phrasing would be in order to make it clear that you’re talking about the “path polygon” having 120 degree interior or exterior angles at each vertex — and that’s language that would probably only help me and not anyone else.
Anyway that belief got me to a contradiction quickly enough that I could then use the other possible bend angle.
09:22.
I think Masyu (and loops on grid cells) doesn’t suit well with hex grid, for reasons mentioned above, but that doesn’t stop this puzzle from being a great one, using the rules well.
27:46