Method dequeue

src/main/java/edu/princeton/cs/algs4/Queue.java:112–119

Removes and returns the item on this queue that was least recently added. @return the item on this queue that was least recently added @throws NoSuchElementException if this queue is empty

()

     * @throws NoSuchElementException if this queue is empty
     */
    public Item dequeue() {
        if (isEmpty()) throw new NoSuchElementException("Queue underflow");
        Item item = first.item;
        first = first.next;
        n--;
        if (isEmpty()) last = null;   // to avoid loitering
        return item;
    }

    /**
     * Returns a string representation of this queue.