我这个贪心策略有什么漏洞吗？为什么只有27分？

#include<bits/stdc++.h>
using namespace std;
typedef long long lld;
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    vector<int>food;
    int n;cin>>n;
    for(int i=1;i<=n;++i)
    {
        int tmp;cin>>tmp;
        food.push_back(tmp);
    }
    long long value=0;
    long long day=1;
    while(food.size())
    {
        int f=food.front();
        int b=food.back();
        if(f<=b)
        {
            food.erase(food.begin());
            value+=f*day;
        }
        else
        {
            food.pop_back();
            value+=b*day;
        }
        ++day;
    }
    cout<<value;return 0;
}