第二周 项目一-旱冰场造价

#include <iostream>
using namespace std;
#define pi 3.1415926
const int M=20;
const int N=35;
class Circle
{
public:
void setRadius(double r);
double area();
double circumference();
private:
double radius;
};
void Circle::setRadius(double r)
{
radius=r;
}
double Circle::area()
{
return pi * radius * radius;
}
double Circle::circumference()
{
return 2*pi*radius;
}

int main()
{
double r;
cout<<"请输入旱冰场的半径: ";
cin>>r;
Circle c;
c.setRadius(r);
cout<<"旱冰场的造价为 "<<M*c.area()+N*c.circumference()<<" 元。"<<endl;
return 0;
}