第十三周实验报告三

#include<iostream>
#include<Cmath>
using namespace std;
const double pi=3.1415926;
class Shape //定义抽象基类
{
public:
virtual double areas()=0;
};

class Circle: public Shape   //利用抽象基类定义圆类
{
public:
Circle(double Circle_radius);//构造函数
~Circle(){}
double areas();
private:
double Circle_radius;
};

class Rectangle: public Shape    //利用抽象基类定义矩形类
{
public:
Rectangle(double Rectangle_long,double Rectangle_wide);//构造函数
~Rectangle(){}
double areas();
private:
double Rectangle_long;
double Rectangle_wide;
};

class Triangle: public Shape  //利用抽象基类定义三角形类
{
public:
Triangle(double Triangle_bottom,double Triangle_high); //构造函数
~Triangle(){}
double areas();
private:
double Triangle_bottom;
double Triangle_high;
};
Circle::Circle(double Circle_radius)//构造函数
{
this->Circle_radius=Circle_radius;
}
double Circle::areas()
{
return (pi*Circle_radius*Circle_radius);
}
Rectangle::Rectangle(double Rectangle_long,double Rectangle_wide)
{
this->Rectangle_long=Rectangle_long;
this->Rectangle_wide=Rectangle_wide;
}
double Rectangle::areas()
{
return (Rectangle_long*Rectangle_long);
}
Triangle::Triangle(double Triangle_bottom,double Triangle_high)
{
this->Triangle_bottom=Triangle_bottom;
this->Triangle_high=Triangle_high;
}
double Triangle::areas()
{
return (Triangle_bottom*Triangle_high/2);
}

int main()
{
Circle c1(12.6),c2(4.9);    //建立Circle类对象c1,c2,参数为圆半径
Rectangle r1(4.5,8.4),r2(5.0,2.5);       //建立Rectangle类对象r1,r2,参数为矩形长、宽
Triangle t1(4.5,8.4),t2(3.4,2.8);    //建立Triangle类对象t1,t2，参数为三角形底边长与高
Shape *pt[6]={&c1,&c2,&r1,&r2,&t1,&t2}; //定义基类指针数组pt，各元素指向一个派生类对象
double areas=0.0;      //areas为总面积
for(int i=0; i<6; i++)
{
areas=areas+pt[i]->areas();
}
cout<<"totol of all areas="<<areas<<endl;   //输出总面积
system("pause");
return 0;
}