第十二周实验报告（三）

/* (程序头部注释开始)
* 程序的版权和版本声明部分
* Copyright (c) 2012, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称：继承和派生

* 作 者：     晁阳
* 完成日期：  2012 年 4 月 23 日
* 版 本 号：  t1.0
* 对任务及求解方法的描述部分
* 输入描述：  继承和派生

*代码实现：

#include<iostream>#include<Cmath>#include<iomanip> #define PI 3.1415926using namespace std;class Point //定义坐标点类{public:Point(){x = 0; y = 0;}Point(double x0, double y0) {x = x0; y = y0;}~Point(){}      double getx(){return x;}      double gety(){return y;}      friend ostream &operator << (ostream & input, Point & c); //重载输入运算符protected:double x, y;   //点的横坐标和纵坐标};  ostream &operator << (ostream & output, Point & c)//重载输出运算符{output << "Point:(" << c.x << ", " << c.y << ")";return output;}class Circle : public Point//声明派生类Point{public:Circle(){r = 0;}Circle(double x0, double y0, double r);     //构造函数       ~Circle(){};      double getr(){return r;}      friend ostream &operator << (ostream & out, Circle & c);  double perimeter0();double area0();protected:double r;};Circle :: Circle(double x0, double y0, double r1) : Point(x0, y0), r(r1){}    //构造函数 ostream &operator << (ostream & output, Circle & c)  {      output << "以" << "(" << c.getx() << "," << c.gety() << ")" << "为圆心， "  << "以" << c.r << "为半径的圆";        return output;  }  double Circle :: perimeter0(){return PI * 2 * r;}double Circle :: area0(){return PI * r * r;}class Cylinder : public Circle{public:Cylinder(){height = 0;}  Cylinder(double x1,double y1, double r1, double h);     ~Cylinder(){}  double area1();double volume();friend ostream &operator << (ostream & output, Cylinder & c); protected:double height;};Cylinder :: Cylinder(double x1,double y1, double r1, double h) : Circle(x1, y1, r1), height(h){}ostream &operator << (ostream & output, Cylinder & c)  {      output << "以" << "(" << c.getx() << "," << c.gety() << ")" << "为圆心, 以" << c.r << "为半径, 以" << c.height << "为高的圆柱体";        return output;  }  double Cylinder :: area1(){return (area0() * 2 + perimeter0() * height);}double Cylinder :: volume(){return area0() * height;}int main()  {      Cylinder cy(1, 2, 4, 5);        cout << cy << endl;        cout << setiosflags(ios::fixed) << setprecision(3);        cout << "表面积是：" << cy.area1() << endl;        cout << "体积是：" << cy.volume() << endl;        system("pause");        return 0;  }  

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