@Raspberryfloof ooh, I've always kind of wondered what the process of designing one of these to ensure solvability without guessing is. And other puzzles in general; I've seen programs that randomly generate puzzles while guaranteeing they will be solvable
@Felthry Amusingly, I tried the harder puzzle in two different solvers, and both reached the same point before getting stuck... but if I added one extra mark that both solvers missed, they were both able to complete the puzzle.
@Raspberryfloof @Felthry I ended up having to test-solve by guessing a square and working from there to see if I hit an unsolvable situation to complete the hard puzzle, admittedly. n.n;
@Felthry For these, I drew a picture, then put the clues into an online solver and checked whether it could find a unique solution from the clues given. I'm sure there's a better way of designing puzzles like these that doesn't rely on trial and error for determining whether a puzzle is uniquely solvable, but I don't know what it would be...