#include<stdio.h>
double sign(int x);
int main()
{
    double x;
    scanf("%d",&x);
    printf("sign(x)=%d\n",sign(x));
    return 0;
     }

        {
        int x;
        if(x>0)
        sign(x)=1;
        else if(x=0)
        sign(x)=0;
        else
        sign(x)=-1;
        return sign(int x);
     }
     请问为什么编译不出来