无论输入什么结果都是0是为啥

Question

#include <stdio.h>
#include <windows.h>
long fac(int n)
{
    float f;
    if(n==0)
    f=1;
    else
    f=n*fac(n-1);
    return f;
}
void main()
{
    float f;
    int n;
    scanf("%d",&n);
    f=fac(n);
    printf("%d!=%d",n,f);
}

Answer 1

float f;
->
int f;