Solution code: Row 1 left to right
on 9. May 2024, 10:33 by chain.reader
hmm, I saw the potential ambiguity in box 9, so I picked the longest bulb to pencilmark, the one in box 9, and left the one in box 8 alone until the very end. fairly quickly the ambiguity goes away by other forces. So this isn't an issue really.
on 7. May 2024, 13:12 by Zarlino
Thank you for this excellent puzzle which has helped me with my phobia of slow thermos! I agree with earlier posters about the slight ambiguity: always best avoided, I feel, as it's off-putting (though fortunately in this instance it wasn't a problem as enough other things had become clear by the time I looked hard at it).
on 6. May 2024, 19:41 by stonetim
Fun puzzle! There isn't really any ambiguity with Box 9 for how it is set-up at the junction of the 2 thermos.
However, I do agree that if there was a 3rd line, or any other shape, there would be a large issue. In those cases, simply color coding the lines makes it easy to delineate.
on 6. May 2024, 17:18 by Mr Toffee
Shortened the solution code to one line.
on 6. May 2024, 16:24 by Karitsu
I don't know exactly what it was about this one, but it was a pretty challenging solve for me. I think it was because of the two thermos joining together in box 9. I ended up restarting 2 or 3 times after realizing I'd screwed up far too late to backtrack to the origin of the issue.