为什么是RE

#include<cstdio>
#include<algorithm>
using namespace std;

int n,a[10005];
float ans;

int main()
{
    scanf("%d",&n);
    for(int i = 1;i <= n;i++) scanf("%d",a[i]);
    sort(a + 1,a + n + 1);
    for(int i = 2;i <= n - 1;i++) ans += a[i];
    printf("%.2f",ans / (n - 2));
    return 0;
}