stack operations using queue

Question

Suppose Stack operations are implemented using Queue Operation. Push(x) and Pop() are stack operations whereas enqueue(x) and dequeue are Queue operations.
Consider the code:

pop()
{
    return Q.dequeue();    
}
push(x)
{
    n= Q.size();    //Q.size() returns the number of elements in the Queue Q.
    Q.enqueue(x);
    for(i=0;i<n;i++)
    {
        X STATEMENT
    }
}

Find the missing statement X STATEMENT to perform Push() operation correctly

(A) Q.enqueue(x)
(B) Q.enqueue(Q.deqeue())
(C) Q.dequeue(Q.enqueue(x))
(D) Q.dequeue()

Comments

It should be B. The program is removing elements in front of the newly inserted element and pushing it back to the queue, so they are now in the back of the newly inserted element.

---

 for(i=1;i<n;i++) //I think it should be 1 here 
    {
        X STATEMENT
    }

Answer 1

First run the push code and enter atleast 2 elements,then perform pop operation