The definitive place to look for answers to questions such as yours, should be the competition rules. As there doesn't seem to be an answer, I suggest sending an email to the address shown for "questions". I don't see why posting or emailing such a question is embarrassing - maybe you'll receive an answer that you don't like. But maybe the clarification would stop somebody else reusing an even better solution out there on the web, that you haven't found yet :).

Regarding the ethics, I do think that using somebody else's solution or part thereof, is going against the spirit of the competition, much in the same way as internet searches in school exams, or using a chess program to help find your moves against online opponents. On the other hand, if you can rattle off the techniques used in past golf solutions from memory, this is perfectly valid. Having another window open with the prior code in it, is to my mind cheating.

That's my take on it. I've never run a golf competition; maybe others can comment.