题目一 简单输出

include "stdio.h"
int main()
{
    printf("fuhao\n");
    return 0;
}

题目二 计算圆的面积

#include<stdio.h>
#define PI 3.14
double calculateSquare(int radius);
int main()
{
  int cRadius=0;
  double square=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;
}