10.5

题目一

#include<stdio.h>
int main()
{
       printf("hello zhengyi");
       return 0;
}

题目二

#include<stdio.h>
#define PI 3.14
double calculateSquare(int radius);
int main()
{
   int cRadius=0；
   double sqare=0.0;
   printf("请输入圆的半径：\n");
   scanf("%d",&cRadius);
   square=calculateSquare(cRadius);
   printf("圆的面积是：%f\n",square);
   return 0;
}
   double calculateSquare(int radius)
{
   double result=PI*radius*radius;
   return result;
}