I think you're going to need a superhuman intelligence's idea of a super-superhuman intelligence at the very least if you're going to expect C programs that are memory safe.

I'll admit that I'd like to do a programming challenge with or without AI that would be like "advent of code" in assembly but if it was actual "advent of code" the direct route is to write something that looks like a language runtime system so you have the dynamic data structures you need on your fingertips.