IsEmpty: return true if a priority queue is empty.

ExtractMin: return the element with the minimum cost from a priority queue

Insert: insert an element into a priority queue

Update: update an existing element in a priority queue

Example

#include “PriorityQueue.h”

CTypedPtrHeap<Node> pq; //initialize the priority queue of integers pq to be empty;

pq.IsEmpty(); //return true;

Node *a,*b,*c; //We assume that the costs in increasing order are a, b, c

pq.Insert(a); // pq=(a)

pq.Insert(b); // pq=(a,b)

pq.Insert(c); // pq=(a,b,c)

Node* d=pq.ExtractMin(); // pq=(b,c); d=a;

//modify c’s key to be the smallest one

pq.Update(c); // update pq to reflect c is modifed; pq=(c, b);

pq.IsEmpty(); //return false;