Calculate the value of a piecewise function using a function

#include<stdio.h>
int sign(int x)
{
	int z;
	if(x>0)
	z = 1;
	if(x==0)
	z = 0;
	if(x<0)
	z = -1;
	return z;
}
intmain()
{
	int n,a;
	scanf("%d",&n);
	a=sign(n);
	printf("sign(%d) = %d",n,a);
	return 0;
}