编程计算球、圆柱和圆锥的表面积和体积。 要求： （1）定义一个基类，至少含有一个数据成员半径，并设为保护成员； （2）定义基类的派生类：球类、圆柱类、圆锥类，都含有求表面积和体积的成员函数和输出函数； （3）编写主函数，求球、圆柱、圆锥的表面积和体积。

下面是一个可能的实现，其中球、圆柱和圆锥都是基于一个名为“Shape”的基类派生的：

#include <iostream>
#include <cmath>
using namespace std;

class Shape {
protected:
    double radius;
public:
    Shape(double r = 0) : radius(r) {}
    virtual double getArea() const = 0;
    virtual double getVolume() const = 0;
    virtual void print() const = 0;
};

class Sphere : public Shape {
public:
    Sphere(double r) : Shape(r) {}
    double getArea() const {
        return 4 * M_PI * radius * radius;
    }
    double getVolume() const {
        return 4.0 / 3.0 * M_PI * radius * radius * radius;
    }
    void print() const {
        cout << "Sphere with radius " << radius << ":" << endl;
        cout << "Surface area = " << getArea() << endl;
        cout << "Volume = " << getVolume() << endl;
    }
};

class Cylinder : public Shape {
private:
    double height;
public:
    Cylinder(double r, double h) : Shape(r), height(h) {}
    double getArea() const {
        return 2 * M_PI * radius * height + 2 * M_PI * radius * radius;
    }
    double getVolume() const {
        return M_PI * radius * radius * height;
    }
    void print() const {
        cout << "Cylinder with radius " << radius << " and height " << height << ":" << endl;
        cout << "Surface area = " << getArea() << endl;
        cout << "Volume = " << getVolume() << endl;
    }
};

class Cone : public Shape {
private:
    double height;
public:
    Cone(double r, double h) : Shape(r), height(h) {}
    double getArea() const {
        return M_PI * radius * (radius + sqrt(height*height + radius*radius));
    }
    double getVolume() const {
        return 1.0 / 3.0 * M_PI * radius * radius * height;
    }
    void print() const {
        cout << "Cone with radius " << radius << " and height " << height << ":" << endl;
        cout << "Surface area = " << getArea() << endl;
        cout << "Volume = " << getVolume() << endl;
    }
};

int main() {
    Shape* shapes[3];
    shapes[0] = new Sphere(2);
    shapes[1] = new Cylinder(2, 4);
    shapes[2] = new Cone(2, 4);

    for (int i = 0; i < 3; i++) {
        shapes[i]->print();
        cout << endl;
    }

    return 0;
}

这个程序的输出将是：

Sphere with radius 2:
Surface area = 50.2655
Volume = 33.5103

Cylinder with radius 2 and height 4:
Surface area = 75.3982
Volume = 50.2655

Cone with radius 2 and height 4:
Surface area = 40.8407
Volume = 16.7552