作业一：简单输出

#include<stdio.h>

int main ()
{
printf("hello QingDao");
return 0;
}

作业二：计算圆的面积

#include<stdio.h>
#define PI 3.14
double caiculateSquare(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;
}