/*

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*/

/**

*

* @author Dell

*/

import java.util.*;

import java.io.*;

import DS.*;

public class QueueUsingLinkedList {

public static Node head;

public static Node tail;

public static void enqueue(int data){

Node current = new Node();

if(head == null){

current.data = data;

current.next = head;

tail = current;

head = current;

}

else{

//we use a tail node to point the tail of the queue,once new node is added it will

// add the address of the new node to the current tail node's next

//hence we can always enqueue in O(1) as we do not have to use the while loop to

// traverse the list and add the new element at the last of the queue.

Node latest = new Node();

latest.data = data;

tail.next = latest;

latest.next = null;

tail = latest;

}

}

public static void print(){

Node temp = head;

while(temp != null){

System.out.print(temp.data+"->");

temp = temp.next;

}

}

public static int dequeue(){

Node temp = head;

head = temp.next;

return temp.data;

}

public static void main(String[] args){

head = null;

enqueue(5);

enqueue(15);

enqueue(25);

enqueue(35);

enqueue(45);

enqueue(55);

enqueue(65);

print();

System.out.println("\n"+dequeue());

print();

}

}