I'm asking this especially after I stumbled on this question myself when I got asked some minutes ago in a comment, if the include in my C code is really neccessary.
I answered that it is, since I need printf which would be implicitly declared if I didn't include the
stdio.h, but that results in unspecified behavior.
(though I can't think of a case where it wouldn't work for that challange so one could argue...)
So are PCG's challenges by default required to be as portable as possible, or will I have succeded as soon I can verify, that there is a system where my golfed code succeeds the challange?