A student writes:

Dear Professor Patt,

I have a quick question about the program.  When you say that at
most the number of ASCII characters will be 20... do you want us to
make the limit of the characters that can be typed into 20?  Or
should we program it to where the message to encode/decode ends only
when enter is inputted?  To make the limit of 20 ascii characters is
a bit trickier, so I'm just trying to understand if we should assume
that at the end of the input that enter will be the last thing.

<<name withheld to protect the overly cautious student>>

I understand that you want to sure of what is expected of you, and I agree
that a test to be sure the user is not allowed to type more than 20
characters takes more work on your part.

We felt that the additional wrinkle you suggest is not necessary to our
ensuring that you have mastered the concepts.  So, we stated "You may assume 
that the message that the user enters will be at most 20 characters long 
(including spaces)."   

Our grading script will not test messages longer than 20 characters, plus 
<enter> (which is not part of the message).


Yale Patt