問題及代碼:
#include <iostream>
using namespace std;
class Shape
{
public:
virtual double area()=0;
};
class Circle:public Shape
{
public:
Circle(double R):r(R){};
double area();
protected:
double r;
};
class Rectangle:public Shape
{
public:
Rectangle(double l,double w):length(l),width(w){};
double area();
protected:
double length,width;
};
class Triangle :public Shape
{
public:
Triangle(double s,double h):side(s),hight(h){};
double area();
protected:
double side,hight;
};
double Circle::area()
{
return 3.14159*r*r;
}
double Rectangle::area()
{
return length*width;
}
double Triangle::area()
{
return 0.5*side*hight;
}
int main()
{
Circle c1(12.6),c2(4.9);//建立Circle類對象c1,c2,參數爲圓半徑
Rectangle r1(4.5,8.4),r2(5.0,2.5);//建立Rectangle類對象r1,r2,參數爲矩形長、寬
Triangle t1(4.5,8.4),t2(3.4,2.8); //建立Triangle類對象t1,t2,參數爲三角形底邊長與高
Shape *pt[6]= {&c1,&c2,&r1,&r2,&t1,&t2}; //定義基類指針數組pt,使它每一個元素指向一個派生類對象
double areas=0.0; //areas爲總面積
for(int i=0; i<6; i++)
{
areas=areas + pt[i]->area();
}
cout<<"totol of all areas="<<areas<<endl; //輸出總面積
return 0;
}
運行結果:
學習小結:
看了一下,這周才三個項目啊。
剛好鏈表不會,可以補補了。
這個寫完了,拿計算器測試了一下,差不多。畢竟有精度差別
寫下一個了!
加油