实验4

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


    printf("Enter r,h:");
    scanf("%lf%lf" ,&r,&h);

    if(r<0,h<0){
        printf("sorry!your enter is wrong!\n");

    }
    else{
        v=3.1415926*r*r*h;
        printf("%.3f\n",v);

    }


    return 0;
}