请各位高手为我纠错··我是初学C++的新手··
#include <iostream.h>{
private:
float r,
;
public:
circle_area();
};
float circle::circle_area(float r)
{
return 4*PAI*r*r;
}
void main()
{
float PAI=3.14;
int s;
circle mycircle;
cin>>r;
s=circle_area();
cout<<"s= "<<s<<endl;
}