If the assignment doesn't permit you to use a certain library and you use it anyway, I don't see why you would expect it to be OK with the instructor. If the a

If the assignment doesn't permit you to use a certain library and you use it anyway, I don't see why you would expect it to be OK with the instructor. If the assignment does permit you to use a certain library and you use it, I don't see why the instructor would complain. If it's ambiguous, then I would possibly ask for clarification. Personally I would expect an assignment using a language like Python, Java, or C++ (for example) to permit use of the standard library (including STL in the case of C++) unless otherwise specified, or unless it was clear that the assignment was to reimplement some function or algorithm which is already part of the standard library.