Round Trip by JinHoo Ahn
or solve online (using our beta test of Penpa-Edit tools; in default linex mode: left-click+drag draws line, right click marks X on edge)
Theme: Sequential Logic
Author/Opus: This is the 33rd puzzle from our contributing puzzlemaster JinHoo Ahn.
Rules: Draw a single loop in the grid which may cross itself orthogonally, but otherwise does not touch or retrace itself. The clue numbers to the left/right of the rows indicate the number of squares visited by the nearest section of the loop that travels horizontally in the rows. The clue numbers to the top/bottom of the columns indicate the number of squares visited by the nearest section of the loop that travels vertically in the columns.
Also, see this example:
Difficulty: 4.5 stars
Time Standards (highlight to view): Grandmaster = 8:30, Master = 14:15, Expert = 28:30
Solution: PDF; a solution video is also available here.
Note: Follow this link for other Round Trip puzzles. Some more Round Trip puzzles can be found in the book Loop Variety Collection by Ashish Kumar and Murat Can Tonta.
24:27.Stunning puzzle !! Right columns at the end were hard to resolve.
Phew, 28:14. Very neat puzzle!
Took much longer to solve, cos I kept track of all my markings. Luckily I did and so there was no backtrack this time!
Something really useful for me is Surface Red/Green for cells that must turn or not. Is there a way to have Right click on surface have another color?
@R – Currently there is no custom option to choose secondary color but If you choose Red Color then right-click already gives green color. Most of the surface colors have right-click as green by default to assist solving.
@Swaroop yes, that’s why I’m using Red/Green, but wanted to use Red/Blue because Line MUST be green, so wanted to stand out from lines and crosses