Halp me with mah homework!!1

Before you do this assignment, you should work through (or at least fully understand)
exercises 7.1 through 7.19, and read carefully through the material in the book,
including the code.  Don?t turn in 7.1 through 7.19.  Your assignment is to do and turn
in exercises 7.20 through 7.25.  (Hint for 7.23: Always save the previous state.)



You may then do exercises 7.29 through 7.34 as extra credit (but do 7.27 and 7.28 first,
without turning them in).  (Hint: Make sure you carefully read the full text before the
exercises, as it will tell you how to do it.)

I don't know what to do, /prog/!

Don't work on exercises 7.1-7.19, but submit them. Then ignore exercises 7.20-7.25. You will lose marks for working on 7.29-7.34, so avoid them at all costs.