Distributed: 8:30 a.m., Monday, 1 November 2004
Due: 9:55 a.m., Monday, 1 November 2004
No extensions.
Contents
There are four problems on the exam. Some problems have subproblems.
Each full problem is worth twenty-five points. The point value associated
with a problem does not necessarily correspond to the complexity
of the problem or the time required to solve the problem.
This examination is closed book, closed computer. However, you may refer
to one, hand-written, double-sided, 8.5 by 11 inch page of notes you have
brought to this exam.
Please write your name on every page of the exam and on your sheet of notes
and submit them together.
You must include both of the following statements on the cover sheet of the
examination. Please sign and date each statement. For this
exam, inappropriate assistance
includes using sources other than
your memory and your one sheet of paper.
1. I have neither received nor given inappropriate assistance on this
examination.
2. I am not aware of any other students who have given
or received inappropriate assistance on this examination.
Because different students may be taking the exam at different times,
you are not permitted to discuss the exam with anyone until after I
have returned it. If you must say something about the exam, you are
allowed to say This is among the hardest exams I have ever
taken.
You may also summarize these policies.
I will give partial credit for partially correct answers. You ensure
the best possible grade for yourself by emphasizing your answer and
including a clear set of work that you used to derive the
answer.
Topics: UML, interfaces, abstract classes.
As we discussed, this semester I had my CSC152 class investigate a number
of alternative ways to write Vector in Two Space
. Here's what
we decided:
- We should have a top-level interface,
Vec2D
- There should be two implementations of
Vec2D: Point (which represents vectors internally using the x and y coordinates of the head) and Polar (which represents vectors internally using the radius and angle of the vector).
- The
equals method belongs in an intermediate abstract class.
Use UML to document these decisions.
Topics: introspection
In a few paragraphs, describe the key ideas and techniques of introspection
in Java. Your description should be clear enough that a classmate who had
not yet tried introspection could use it on the take-home exam.
a. List five key principles of XP. Describe each with a sentence of two.
1.
2.
3.
4.
5.
b. Pick two pairs of principles and, for each pair, descibe how the two principles reinforce each other.
1.
2.
Topics: Sorting, testing, JUnit
Suppose we've designed the following abstract class.
/**
* Things that know how to sort.
*/
public abstract class Sorter
{
protected Comparator comparator;
/**
* Build a sorter that uses a particular comparator to
* order the elements.
*/
public Sorter(Comparator _comparator)
{
this.comparator = _comparator;
} // Sorter(Comparator)
/**
* Sort an array of elements in place using the previously
* specified comparator.
*/
public abstract void sort(Object[] unsorted);
} // class Sorter
Suppose we have also subclassed this class with the Quicksorter
class.
Sketch an appropriate JUnit test suite for the sort method
in Quicksorter. (If you want to build a more general test
suite and subclass it for Quicksorter, that's fine, too.)
;
Check with Bobby