编写内联函数CalArea(double radius)来求圆的面积(其中:Pi=3.14)。
#include <iostream>
#define pi 3.14
using namespace std;
double CalArea(double &r)
{
return pi*r*r;
}
int main()
{
double radius, area;
cin >> radius;
double r(radius);
area = CalArea(r);
cout << area << endl;
}