/***************************************************************
* Name: Prof. Rafael Orta
* Course: Computer Science & Programming
* Class: CS04225 Section: 4
* Assignment Date: 03/06/21
* File Name: Queue.cpp
*****************************************************************
*
* Purpose: Implementation of a queue using linked lists
*
*****************************************************************/
#include <iostream>
#include <string>
using namespace std;
struct QNode
{
string data;
QNode* next;
QNode(string d)
{
data = d;
next = NULL;
}
};
struct Queue {
QNode *front, *rear;
Queue()
{
front = rear = NULL;
}
void enQueue(string x)
{
// Create a new LL node
QNode* temp = new QNode(x);
// If queue is empty, then
// new node is front and rear both
if (rear == NULL) {
front = rear = temp;
return;
}
// Add the new node at
// the end of queue and change rear
rear->next = temp;
rear = temp;
}
// Function to remove
// a key from given queue q
void deQueue()
{
// If queue is empty, return NULL.
if (front == NULL)
return;
// Store previous front and
// move front one node ahead
QNode* temp = front;
front = front->next;
// If front becomes NULL, then
// change rear also as NULL
if (front == NULL)
rear = NULL;
delete (temp);
}
};
// Driven Program
int main()
{
cout << "************************************************\n";
cout << " E N Q U E U I N G \n";
cout << "************************************************\n\n";
Queue q;
q.enQueue("Halley");
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.enQueue("Christina");
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.enQueue("Jazz");
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.enQueue("Sofia");
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.enQueue("Margot");
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl << endl;
cout << "************************************************\n";
cout << " D E - Q U E U I N G \n";
cout << "************************************************\n";
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.deQueue();
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.deQueue();
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.deQueue();
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.deQueue();
cout << "Queue Front : " << (q.front)->data << endl;
cout << "Queue Rear : " << (q.rear)->data << endl;
q.deQueue();
}
