Convert this program to C++, write comments where needed and include a summary of the program: Implement a RandomQueue:

import java.util.Iterator; public class RandomizedQueue implements Iterable { private int size; private Node head, tail; private class Node { Item item; Node next; Node prev; } public RandomizedQueue() { head = new Node(); head.next = null; head.prev = null; head.item = null; tail = head; } public boolean isEmpty() { return tail == head; } public int size() { return size; } public void enqueue(Item item) { if (item == null) throw new java.lang.NullPointerException( " adding null values is not allowed "); else { Node oldTail = tail; tail = new Node(); tail.item = item; tail.next = null; tail.prev = oldTail; oldTail.next = tail; size++; } } private Node getRanPointer() { int ran = 1 + StdRandom.uniform(size); // since head is a sentinel, so // actual database starts after // head , hence 1 is added Node pointer = head.next; for (int i = 1; i < ran; i++) { // as data starts from index 1 instead // of index 0 (which denotes the head) pointer = pointer.next; } return pointer; } public Item dequeue() { if (isEmpty()) throw new java.util.NoSuchElementException( " cannot remove from an empty deque"); else { Node pointer = getRanPointer(); Item item; if (pointer == head) { item = head.item; head = head.next; head.prev = null; size--; } else if (pointer == tail) { item = tail.item; tail = tail.prev; tail.next = null; size--; } else { item = pointer.item; pointer.prev.next = pointer.next; pointer.next.prev = pointer.prev; pointer = null; // deletes the pointer size--; } return item; } } public Item sample() { if (isEmpty()) throw new java.util.NoSuchElementException( " cannot remove from an empty deque"); else { Node pointer = getRanPointer(); return pointer.item; } } @Override public Iterator iterator() { return new Iterator() { private Node current = head.next; @Override public boolean hasNext() { return current != null; } @Override public Item next() { if(current == null) throw new java.util.NoSuchElementException("no more items to iterate"); Item temp = current.item; current = current.next; return temp; } @Override public void remove() { throw new UnsupportedOperationException( "remove is illegal to use as per the API"); } }; } }