/*

* File: main.cpp

* Author: ngupta94

*

* Created on January 21, 2014, 11:53 AM

*/

#include <cstdlib>

#include <iostream>

using namespace std;

struct node //one element of stack

{

int data; //data item

node* next; //pointer to next link

};

class queue //a list of links

{

private:

node* head; //pointer to first link

public:

queue() //no-argument constructor

{

head = NULL;

} //no first link

void enqueue(int d); //add data item (one link)

void display(); //display all link

int dequeue();

};

void queue::enqueue(int d) //add data item

{

node *newNode = new node;

newNode->data = d;

newNode->next = head;

head = newNode;

return;

}

int queue::dequeue() {

node *tmp, *cur;

int d;

if (head == NULL) {

cout << "List Empty " << endl;

return(-1);

} else {

cur = head;

while (head != NULL) {

tmp = head;

d = head->data;

head = head->next;

}

delete tmp;

head = cur;

}

return(d);

}

void queue::display() //display all links

{

node* current = head; //set ptr to first link

while (current != NULL) //quit on last link

{

cout << current->data << endl; //print data

current = current->next; //move to next link

}

}

/*

*

*/

int main(int argc, char** argv) {

queue q1;

int ret;

q1.enqueue(56);

ret = q1.dequeue();

if (ret >=0 ) {

cout << "dequeue = " << ret << endl;

}

ret = q1.dequeue();

if (ret >=0 ) {

cout << "dequeue = " << ret << endl;

}

q1.enqueue(17);

q1.enqueue(54);

q1.enqueue(23);

q1.enqueue(87);

ret = q1.dequeue();

if (ret >=0 ) {

cout << "dequeue = " << ret << endl;

}

ret = q1.dequeue();

if (ret >=0 ) {

cout << "dequeue = " << ret << endl;

}

q1.display();

return 0;

}