This is how the Facebook puzzles work except that you only get a pass/fail response. To help people ensure that they aren't failing due to some sort of packagin

This is how the Facebook puzzles work except that you only get a pass/fail response. To help people ensure that they aren't failing due to some sort of packaging problem, they have simple puzzles (one step up from hello world), and it's not frowned upon to help someone with those. What Facebook puzzlers end up doing is creating their own testcases and validating that those testcases encompass all the interesting corner cases and are complex enough to prove the efficiency of the algorithm in use. Perhaps the hidden bit of learning from "The System" is that it forces students to think through the entire scope of possible inputs for their program and ensure they test against a representative set of cases.