We will soon begin to regularly post Yajilin puzzles here. Yajilin is a style that is quite different from the other loop styles we have at the moment. Most of those have to do with how a loop travels in small regions. Masyu puzzles, for example, contain clues that require a loop to go straight or turn in specific cells; most of the logic focuses around how to make the loop obey these path instructions. Yajilin is focused more on where a loop travels, which is almost everywhere in the grid. As a variation on other “visit all cells” loop puzzles, the logic in Yajilin revolves around how to get in and out of every part of the grid with only a few cells untouched.
While the style may be familiar, our Yajilin will not look exactly like the Yajilin puzzles you are used to seeing elsewhere. We strongly believe that a wider range of puzzles, and more interesting puzzles, are possible if constructors are allowed to mark some cells as “unused” — neither white nor black. In the standard format, all of these spots would then need arrow clues resulting in excessive and often redundant clues that can subtract from the potential aesthetics or logic of a puzzle. It would simply be impossible to make a standard Yajilin with the curious but pedagogical properties of this example puzzle below.
Increasing the flexibility for the puzzle designer to include known spots that the loop cannot enter seems to meaningfully increase the range of possible Yajilin puzzles. So this is what Grandmaster Puzzles will do with our Yajilin puzzles (although sometimes they may still look “classic”). We hope the change only adds to your enjoyment of this puzzle style.
PDF
or solve online (using our beta test of Penpa-Edit tools)
Theme: Easy as (0,) 1, 2, 3?
Rules: Standard Yajilin rules.
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 = 1:15, Master = 2:30, Expert = 5:00
Solution: PDF