题目一：简单输出

#include<stdio.h>
#define PI 3.14
double calculateArea (int radius);
int main ()
{
  int cRadius =0;
  double Area =0.0;
  printf("???????:\n");
  scanf("%d",&cRadius);
  Area=calculateArea(cRadius);
  printf("?????:%f\n",Area);
  return 0;
}
  double calculateArea (int radius)
{
  double result = PI*radius*radius;
  return result;
}
20:48:40
???? 2017/10/10 20:48:40
#include<stdio.h>
#define PI 3.14
double calculateArea (int radius);
int main ()
{
  int cRadius =0;
  double Area =0.0;
  printf("???????:\n");
  scanf("%d",&cRadius);
  Area=calculateArea(cRadius);
  printf("?????:%f\n",Area);
  return 0;
}
  double calculateArea (int radius)
{
  double result = PI*radius*radius;
  return result;
}