求告知哪里错了 顺便帮我改正一下
#include<stdio.h>float yuan(float x);
float yuanmianji(float x);
float yuanzhu(float x,float y);
float zhouchang(float x,float y);
main()
{
float yuan(float x);
float yuanmianji(float x);
float yuanzhu(float x,float y);
float zhouchang(float x,float y);
float x,k;
int n;
printf("选择要计算体积的图形: \n");
printf("1 圆体积 \n");
printf("2 圆面积 \n");
printf("3 圆柱面积 \n");
printf("4 圆柱周长 \n");
scanf("%d",&n);
switch(n)
{
case 0:k=0;break;
case 1:k=yuan(x);break;
case 2:k=yuanmianji(x);break;
case 3:k=yuanzhu(x,y);break;
case 4:k=zhouchang(x,y);break;
default:printf("输入有错! \n");break;
}
}
float yuan(float x)
{
float a;
printf("请输入圆的半径: \n");
scanf("%f",&x);
a=3.14*(x*2);
printf("圆的体积是:%f \n",a);
return a;
}
float yuanmianji(float x)
{
float a;
printf("请输入圆半径: \n");
scanf("%f",&x);
a=3.14*(x*x);
printf("圆的面积是:%f \n",a);
return x;
}
float yuanzhu(float x,float y)
{
float a;
printf("请输入半径和高: \n");
scanf("%f %f",&x,&y);
a=3.14*(x*x)*y;
printf("圆柱的表面积是:%f \n",a);
return a;
}
float zhouchang(float x,float y)
{
float a;
printf("请输入半径和高: \n");
scanf("%f %f",&x,&y);
a=2*3.14*x(x+y);
printf("圆柱的周长是:%f \n",a);
return a;
}
