queue Algorithm
In computer science, a priority queue is an abstract data type like to regular queue or stack data structure in which each component additionally has a" priority" associated with it. In a priority queue, an component with high priority is served before an component with low priority.
#include <iostream>
#include <assert.h>
#include "queue.h"
using namespace std;
/* Default constructor*/
template <class Kind>
queue<Kind>::queue()
{
queueFront = NULL;
queueRear = NULL;
size = 0;
}
/* Destructor */
template <class Kind>
queue<Kind>::~queue()
{
}
/* Display for testing */
template <class Kind>
void queue<Kind>::display()
{
node<Kind> *current = queueFront;
cout << "Front --> ";
while(current != NULL) {
cout<<current->data<< " ";
current = current -> next;
}
cout <<endl;
cout << "Size of queue: " << size << endl;
}
/* Determine whether the queue is empty */
template <class Kind>
bool queue<Kind>::isEmptyQueue()
{
return (queueFront == NULL);
}
/* Clear queue */
template <class Kind>
void queue<Kind>::clear()
{
queueFront = NULL;
}
/* Add new item to the queue */
template <class Kind>
void queue<Kind>::enQueue(Kind item)
{
node<Kind> *newNode;
newNode = new node<Kind>;
newNode->data = item;
newNode->next = NULL;
if (queueFront == NULL) {
queueFront = newNode;
queueRear = newNode;
} else {
queueRear->next = newNode;
queueRear = queueRear->next;
}
size++;
}
/* Return the top element of the queue */
template <class Kind>
Kind queue<Kind>::front()
{
assert(queueFront != NULL);
return queueFront->data;
}
/* Remove the element of the queue */
template <class Kind>
void queue<Kind>::deQueue()
{
node<Kind> *temp;
if(!isEmptyQueue()) {
temp = queueFront;
queueFront = queueFront->next;
delete temp;
size--;
} else {
cout << "Queue is empty !" << endl;
}
}
