For each general purpose data structure that you used, answer each 
of the following questions:

1. Why did you choose this data structure? What alternatives did you
consider?

2. What are the key operations? What is the time performance of
each of those operations?

3. What application specific methods were you tempted to add? Did
you make a new class that inherits from the general class? Justify
any non-standard methods that you did include.