第10周实验报告任务3

/* (程序头部注释开始)  
* 程序的版权和版本声明部分 

* Copyright (c) 2011, 烟台大学计算机学院学生  

* All rights reserved.* 文件名称：点、圆、圆柱 
* 作 者： 郭岩岩 

* 完成日期：2012 年4月 24日 

* 版 本 号： vc.1 

* 对任务及求解方法的描述部分 

* 输入描述：  

* 问题描述：  

* 程序输出：  

*程序头部的注释结束 
*/

#include<iostream>
using namespace std;
class Point //定义坐标点类
{public:
Point(double a=0,double b=0);
void setpoint(double c,double d);
double getx(){return x;}
double gety(){return y;}
friend ostream &operator<<(ostream &output,Point &p);
protected:
	double x,y;
};
Point::Point (double a,double b)
{
	x=a;
	y=b;
}
void Point::setpoint(double c,double d)
{
	x=c;
	y=d;
}
ostream& operator<<(ostream &output,Point &p)
{
	output<<"("<<p.x <<","<<p.y<<")"<<endl;
	return output;
}
class Circle:public Point
{
public:
	Circle(double a,double b,double c);
	void setr(double);
	double getr(){return r;}
	double area();
	friend ostream & operator<<(ostream & output,Circle & c);
protected:
	double r;
};
Circle::Circle(double a,double b,double c):Point(a,b)
{
	r=c;
}
void Circle::setr(double c)
{
	r=c;
}

double Circle::area()
{
	return 3.1415926*getr()*getr();
}
ostream & operator<<(ostream & output,Circle &c)
{
	output<<"圆心为：("<<c.x<<","<<c.y <<")"<<"半径为："<<c.getr()<<"面积为:"<<c.area()<<endl;
	return output;
}
class Cylinder:public Circle
{
public:
	Cylinder(double a,double b,double c,double d);
	double geth(){return h;}
	void seth(double d);
	double volume();
	double area();
	friend ostream & operator<<(ostream &output,Cylinder &cy);
protected:
	double h;
};
Cylinder::Cylinder(double a,double b,double c,double d):Circle(a,b,c),h(d){}
	


void Cylinder::seth(double d)
{
	h=d;
}
double Cylinder::volume()
{
	return Circle::area()*h;
}
double Cylinder::area()
{
	return 2*Circle::area()+2*3.1415926*getr()*h;
}
ostream & operator<<(ostream &output,Cylinder &cy)
{
	output<<"圆心为：("<<cy.x<<","<<cy.y <<")"<<"半径为："<<cy.getr()<<"面积为:"<<cy.area()<<"表面积为："<<cy.volume()<<endl;
	return output;
}
int main( )  
{  
    Cylinder cy1(3.5,6.4,5.2,10);  
    cout<<"\noriginal cylinder:\nx="<<cy1.getx( )<<", y="<<cy1.gety( )<<", r="  
        <<cy1.getr( )<<", h="<<cy1.geth( )<<"\narea="<<cy1.area()  
        <<",volume="<<cy1.volume()<<endl;  
    cy1.seth(15);       
    cy1.setr(7.5);        
    cy1.setpoint(5,5);         
    cout<<"\nnew cylinder:\n"<<cy1;          
    system("pause");  
    return 0;  
} 

original cylinder:
x=3.5, y=6.4, r=5.2, h=10
area=496.623,volume=849.487

new cylinder:
圆心为：(5,5)半径为：7.5面积为:1060.29表面积为：2650.72
请按任意键继续. . .

经验积累：在定义派生类构造函数时，要调用基类的构造函数;

                    在用到基类和派生类同名的函数时要写明作用域

 上机感言：小小字符不可忽视，忘写<<和;导致出现好多bug;