We had something similar at Purdue. In fact, we were frequently given an example 'correct' program whose output we needed to match exactly. It took me much lo

We had something similar at Purdue. In fact, we were frequently given an example 'correct' program whose output we needed to match exactly. It took me much longer to get register assignment in my compilers' class to match the professor's results than it took me to get it 'correct'. This gets to interfaces though. I don't know about the gp, but if the assignment specifies a particular interface then that becomes a part of the spec. It doesn't matter that you made a more advanced interface, if it doesn't match the required interface it's wrong.