// 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; } }
public Queue1() { this.front = this.rear = null; }
// constructor to create // a new linked list node public QNode(int key) { this.key = key; this.next = null; }