No extra credit is available for programs submitted late. If you submit a program early, you will get early credit, which will offset late penalties on other programs. Excess early credit has no value. The absolute deadline for submitting programs is Wednesday of the last week of class. No assignments will be accepted after that time.
Internal documentation consists of the comments included in the program.
Procedure-head comments describe the effects of the procedure and assumptions about its inputs and outputs. The procedure name should convey as much of this information as possible. Names of variables, types, constants, and field selectors should also be as meaningful as possible, with a comment next to the declaration to fill in extra information. Such comments should be written before the rest of the program. Your code should be as clear and simple as possible, but occasionally you may need to resort a clever trick.