照着题解的思路写，结果还是这样

#include<bits/stdc++.h>
using namespace std;
const long long Max = 100005;
long long n;
double maxn;
double a[Max],sum[Max],mnn[Max],ans[Max]; 
int main()
{
	cin >> n;
	memset(mnn,100005,sizeof(mnn));
	for (int i = 1;i <= n;i++){
		cin >> a[i];
	}
	for (int i = n;i >= 2;i--){
		mnn[i]=min(mnn[i+1],a[i]);
		sum[i] = sum[i+1] + a[i];
		if (i != n)
			ans[i] =(sum[i]-mnn[i])/(double)(n-i);
	}
	for (int i = 2;i <= n-1;i++){
		maxn = max(maxn,ans[i]);
	}
	for (int i = 2;i <= n-1;i++){
		if (maxn == ans[i])
			cout << i-1 << endl;
	}
	return 0;
}  

dalao救救孩子吧