// Heapable.java

// To make a Heap that can handle many kinds of data, have it
// manipulate Heapable objects.  To be able to put a kind of
// object into a heap, that object's class must implement
// the Heapable interface, as defined here.

interface Heapable {
	// returns the object's key -- we say it must be an int
	public int getKey(); 
}