These files specify the abstract PriorityQueue interface and
the specification of a BinaryHeap, which should implement the PriorityQueue
interface. Note that you are responsible not only for implementing a
PriorityQueue ADT, but for testing it as well. To start you off, we
have provided a simple test program, but you should also write your
own (or several of them!). To compile the test program, use the
Makefile provided for you, and type
"make pq-test"