课堂练习二

#include<stdio.h>
int main(void)
{
int i,n;
double h,r,v;
double cylinder(double r,double h);

printf("Enter n:");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
printf("Enter r and h:");
scanf("%lf%lf",&r,&h);

if((r<=0)||(h<=0))
{
  printf("输入错误，重新输入");
}
else
{
  v=cylinder(r,h);
  printf("v=%.3f\n",v);
}