首先构建一个Point(点)类，包含数据成员x、y(坐标点)。以它为基类，派生出一个Circle(圆)类，增加数据成员r(半径)，再以Circle类为直接基类，派生出一个Cylinder(圆柱体)类，再增加数据成员h(高)。并且重载运算符“<<”，使之能用于输出Cylinder类的对象。最后在主函数中实例化Cylinder类，并通过cout显示。c++

以下是代码实现：

#include <iostream>
using namespace std;

class Point {
public:
    Point(double xx = 0, double yy = 0) : x(xx), y(yy) {}
    friend ostream& operator<<(ostream& os, const Point& p) {
        os << "(" << p.x << "," << p.y << ")";
        return os;
    }
protected:
    double x, y;
};

class Circle : public Point {
public:
    Circle(double xx = 0, double yy = 0, double rr = 0) : Point(xx, yy), r(rr) {}
    friend ostream& operator<<(ostream& os, const Circle& c) {
        os << "Center: " << static_cast<Point>(c) << ", Radius: " << c.r;
        return os;
    }
protected:
    double r;
};

class Cylinder : public Circle {
public:
    Cylinder(double xx = 0, double yy = 0, double rr = 0, double hh = 0) : Circle(xx, yy, rr), h(hh) {}
    friend ostream& operator<<(ostream& os, const Cylinder& cyl) {
        os << "Base: " << static_cast<Circle>(cyl) << ", Height: " << cyl.h;
        return os;
    }
protected:
    double h;
};

int main() {
    Cylinder cyl(1, 2, 3, 4);
    cout << cyl << endl;
    return 0;
}

输出结果为：

Base: Center: (1,2), Radius: 3, Height: 4