Suppose the stack operations are implemented using the queue operations. Push(x) and Pop() are stack operations whereas enqueue(x) and dequeue() are queue operations.
Consider the following code
Pop() {return Q.dequeue();}
Push(x)
{
n=Q.size(); /*Q.size() returns the number of elements in queue Q*/
Q.enqueue(x);
For(i=0; i }
1
Q.enqueue(x);
2
Q.enqueue(Q.dequeue());
3
Q.dequeue(Q.enqueue(x));
4
Q.dequeue();