#include <stdio.h>
#define PI 3.14159
void main()
{
    double zhu(double x,double y);
    double zhui(double x,double y);
    double r,h,v1,v2,sum;
    printf("请输入圆锥体、圆柱体的半径和高:");
    scanf("%lf%lf",&r,&h);
    do
    {v1=zhu(r,h);
    v2=zhui(r,h);
    sum=v1+v2;
    printf("圆锥体体积+圆柱体体积=%lf\n",sum);}
    while(r!=0);
}
double zhu(double x,double y)
{
    double v1;
    v1=PI*x*x*y;
    return (v1);
}
double zhui(double x,double y)
{
    double v2;
    v2=PI*x*x*y/3;
    return(v2);
}

精度数的数值不是准确的，你们学习的时候应该有人强调的吧

fabs(r) <= 0.0000001

#include <stdio.h>
#define PI 3.14159
double zhu(double x,double y);
double zhui(double x,double y);
int main()
{
    double r,h,v1,v2,sum;
    printf("请输入圆锥体、圆柱体的半径和高:");
    scanf("%lf%lf",&r,&h);
    if(r<=0||h<=0)
        return -1;
    else
    {
        v1=zhu(r,h);
        v2=zhui(r,h);
        sum=v1+v2;
        printf("圆锥体体积+圆柱体体积=%lf\n",sum);
    }
    return 0;
}
double zhu(double x,double y)
{
    double v1;
    v1=PI*x*x*y;
    return (v1);
}
double zhui(double x,double y)
{
    double v2;
    v2=PI*x*x*y/3;
    return(v2);
} 

你要表达什么意思？首先函数申明写错地方了。再者，while循环是干什么的？

这是什么意思  我想知道怎样才可以重复输入

要重复输入半径和高直到半径为0时结束

你在do while里面根本没有对r和h做输入，怎么可能r 和h的值会变化呢？

嗯嗯  现在我知道周末错了  谢谢了哈

重复输入是 while(1){  } 吧...

+1
正确答案

#include <stdio.h>

#ifndef M_PI
#define M_PI       3.14159265358979323846
#endif

double volume_of_cone( double r, double h );
double volume_of_column( double r, double h );

int main()
{
    while( 1 )
    {
        double r, h, v1, v2;
        printf("请输入圆锥体、圆柱体的半径和高:");
        if( scanf("%lf%lf",&r,&h)!=2 || r==0 )
            break;

        v1 = volume_of_cone( r, h );
        v2 = volume_of_column( r, h );

        printf( "圆锥体体积+圆柱体体积=%lf\n", v1+v2 );
    }

    return 0;
}
double volume_of_cone( double r, double h )
{
    return M_PI*r*r*h;
}
double volume_of_column( double r, double h )
{
    return M_PI*r*r*h/3;
}