#include <iostream.h>
#include <math.h>

// class declaration for the base class

class One
{
  protected:
    float a;
  public:
    One(float = 2);    // constructor
    float f1(float);   // a member function
    float f2(float);   // another member function
};

// class implementation for One

One::One(float val)   // constructor
{
  a = val;
}

float One::f1(float num)  // a member function
{
  return(num/2);
}
float One::f2(float num)  // another member function
{
  return( pow(f1(num),2) );  // square the result of f1()
}

// class declaration for the derived class

class Two : public One
{
  public:
    float f1(float);    // this overrides class One's f1()
};

// class implementation for Two

float Two::f1(float num)
{
  return(num/3);
  }

int main()
{
  One object_1;  // object_1 is an object of the base class
  Two object_2;  // object_2 is an object of the derived class

     // call f2() using a base class object call
  cout << "The computed value using a base class object call is "
       << object_1.f2(12) << endl;

    // call f2() using a derived class object call
  cout << "The computed value using a derived class object call is "
       << object_2.f2(12) << endl;

  return 0;
}