//myq4.h  -- queue using vector  (not GOOD)
#ifndef __MYQ4__
#define __MYQ4__
#include <vector>
using namespace std;
template <class T>
class MyStack : vector<T> {   // actually is a queue
public:
   void push(const T& y) {
      MyStack<T>::push_back(y);
   }
   T top( ) {
      return MyStack<T>::front( ); 
      return  vector<T>::front( );  // OK too
      //return this -> front( );  // this is also OK
   }
   void pop( ) {
      MyStack<T>::erase( MyStack<T>::begin( ) );
   }
   bool empty( ) { return MyStack<T>::begin() == MyStack<T>::end(); }
};
#endif