练习2

#include<stdio.h>
int main(void)
{
    double height,radius,volume;/*定义实数型双精度浮点型变量*/
    int n,i;/*定义整型变量*/
    double cylinder(double r,double h);/*定义双精度浮点型变量*/
    printf("Enter n");
    scanf("%d",&n);
    for(i=1;i<=n;i++){/*设置循环*/
    printf("Enter radius and height:");
    scanf("%lf%lf",&radius,&height);
        if(height>=0&&radius>=0){/*判断语句高度和半径是否大于0*/
            volume=cylinder(radius,height);
            printf("Volume=%.3f\n",volume);
        }
        else{
            printf("输入错误");
        }
          }
        return 0;
}
double cylinder(double r,double h)
{
    double result;
    result=3.1415926*r*r*h;
    return result;
}