When you read the specs of what you need to implement, pay attention to the meaning of words. The specs are usually clearly spelled out. When it's unclear what is meant by a spec, go and ask the TAs or the profs. After you put all that work in getting the functionality done, don't just throw away the easy marks you could get from testing. 2. special cases - your tests show me that your code works when used by the clinically insane.
Most people cover case one.
Only some have a good attempt at case 2. I think students are assuming too much sanity on our part, the TAs. A point to remember is that the TAs have more experience in crashing nachos, and they may use it during testing. People are quite confused about what goes into a design document. This are some guidelines which will help you in getting a better mark.