// Method to add an key to the queue.
public void enqueue(int key)
{
// Create a new LL node
QNode temp = new QNode(key);
// If queue is empty, then new
// node is front and rear both
if (this.rear == null)
{
this.front = this.rear = temp;
return;
}
// Add the new node at the
// end of queue and change rear
this.rear.next = temp;
this.rear = temp;
}
// Method to remove an key from queue.
public void dequeue()
{
// If queue is empty, return NULL.
if (this.front == null)
{
return;
}
// Store previous front and
// move front one node ahead
QNode temp = this.front;
this.front = this.front.next;
// If front becomes NULL,
// then change rear also as NULL
if (this.front == null)
{
this.rear = null;
}
}
// constructor to create
// a new linked list node
public QNode(int key)
{
this.key = key;
this.next = null;
}
public Queue()
{
this.front = this.rear = null;
}