程序代码：

#include<stdio.h>
#include <malloc.h>
#define PI 3.1415
class Ball
{
public:
    Ball(float r);
    ~Ball();
    float Area();
    float Size();
private:
    float r;
};

Ball::Ball(float r)
{
    this->r = r;
}

Ball::~Ball()
{
}

float Ball::Area()
{
    return 4*PI*r*r;
}

float Ball::Size()
{
    return 1.3333*PI*r*r*r;
}
int main()
{
    Ball b(3);
    printf("%lf\n",b.Area());
    printf("%lf\n",b.Size());
    return 0;
}