用C++程序写一个圆类，类中能求出周长及面积

Question

如题所述

Answer 1

现写了一个，你看看有没有问题。
#include "iostream.h"
#define PIE 3.1415926
struct point //
{
double x;
double y;
};

class circle
{
private:
point o;//圆心
double r; //半径
double area;//面积
double perimeter;//周长
public:
void getor(point a,double d);
void comarea();//计算面积
void comperi();//计算周长
double getarea(){return area;}
double getperi(){return perimeter;}
};
void circle::getor(point a,double d)
{
o=a;
r=d;
}
void circle::comarea()
{
area=r*r*PIE/2;
}
void circle::comperi()
{
perimeter=2*r*PIE;
}

int main()
{
circle c;
double d;
point temp;
cout<<"输入圆心横坐标:\t";
cin>>temp.x;
cout<<"输入圆心纵坐标:\t";
cin>>temp.y;
cout<<"输入圆半径:\t";
cin>>d;
c.getor(temp,d);
c.comarea();
c.comperi();
cout<<"面积为:\t"<<c.getarea()<<endl;
cout<<"周长为:\t"<<c.getperi()<<endl;
return 0;
}