โปรแกรมการหา Factorial

#include <stdio.h>
void main()
{
int count;
int fac;
int ans =1;

printf("Please Enter number: ");
scanf("%d",&fac);

count = fac;
while(count>0)
{
ans = ans*count;
count--;
}
printf("%d! = %d\n",fac,ans);
}