求救C语言高手!!!!

void main()
{
printf("请输入圆的半径");
float d=0;
scanf("%f",&d);
if(d<0)
{
printf("半径小于0！");
return ;
}
float area=3.1415926*d*d;
float girth=d*2*3.1415926;
printf("圆的面积是：%f,周长是%f",area,girth);
//ExitThread(0);

}

//VC下运行通过
#include "stdio.h"
#define PI 3.1415926

int circle1(double r,double* l,double* s)
{
if(r<0) return(0);

*l=2*PI*r;
*s=r*r*PI;
return(1);
}

void main()
{
double r,l,s;

printf("\nr=");
scanf("%lf",&r);
if(circle1(r,&l,&s)) printf("\nr=%lf,l=%lf,s=%lf\n",r,l,s);
else
printf("\nvalid input\n");
}

#include <stdio.h>
int main(void)
{
float r;
scanf("%f",&r);
printf("%f\n",r*r*3