class circle
{
double rd;//半径成员
public:
circle()
{
rd=0.0;
}//构造函数
cirle(double b)
{
rd=b;
}//重构构造函数
double zc()
{
return 2*pi*rd;
}
double mj()
{
return pi*rd*rd;
}
}
class Circle
{
private:
double r;
public:
Circle(double rr=0.0):r(rr){};
double around()
{return 2*PI*r;}
double square()
{return PI*r*r;}
};