My answer -- to the explicit question "do you think this ... is a bit much to ask?" goes not to the issue of whether the answer would be an appropriate use of Perl, but rather to an at-least-plausible interpretation of the question, "do you think this is appropriate homework?"

My answer has to be a resounding "Yes!" -- qualified only by the kind of question jethro raised... which, rephrased, might be, "is this too hard for (level-of-students)?"

Of course, I can't psi the instructor's pedagological intent, but -- again, depending on the skill levels expected of students at this stage of the particular course -- it seems to me that it might encompass two objectives: 1) encouraging the student to develop (or select) a decent algorithm and 2) to express that in a concise script (one-liner).