Masyu (Windows) by Prasanna Seshadri
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 112th puzzle from our contributing puzzlemaster Prasanna Seshadri.
Rules: Standard Masyu rules. Also there are two windows in the upper left (blue) and lower right (red) of the grid. If the loop passes through a cell in one window by going straight, it must go through the same cell in the other window by turning; the converse is also true. (It is possible for the cells to be unused by the loop in both windows.)
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 = 3:30, Master = 5:15, Expert = 10:30
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.
I had to assume that the rules also include “If the loop passes through a cell in one window by turning, it must go through the same cell in the other window by going straight.”
Huh… I assumed that rule too… It wasn’t until I came to post my answer string and saw your comment that I realised that the rules don’t actually explicitly state that…
Since the two Windows aren’t given a ranking (its not Window 1 depends on Window 2 or vice versa, its both of them depending on each other), I think the implication is clear enough that when one is straight if the other must be a turn, then that works vice versa too.
Given that that’s how I initially read it, I’m tempted to agree, however I do see Rob’s point. If the path goes straight though a in either window it’s a given that the path must turn in the equivalent cell in the other window, but the current wording does suggest that it might not work the other way around, i.e. if the path turns in one window, it might go go straight through in the other window, or it might also turn at that point, because it’s not explicitly stated otherwise.
-SC
I’ve added that the converse is true so that there isn’t this small hole in the instructions.
I had a different idea about using the windows rule for loops. When 2 segments are used in one window, in the other window the other 2 segments have to be used. I think this one is a bit less forcing and more interesting, to be honest. (E.g if one cell uses top and left, the other cell uses bottom and right.)
That does sound interesting to try out. My thinking behind using straights and turns here was mainly that Masyu is a puzzle about straights and turns and I thought that it links up well because of that.
14:20