Homelander

int n,mid_index=0;
    cin >> n;
    int arr[n],b[n];
    ll sum_l[n + 1]{}, sum_r[n + 1]{};
    for (int i = 0; i < n;i++)
    {
        cin >> arr[i];
        b[i] = arr[i];
    }
    reverse(b, b + n);
    for (int i = 0; i < n;i++)
        sum_l[i + 1] = sum_l[i] + arr[i];
    for (int i = 0; i < n;i++)
        sum_r[i+1] = sum_r[i] + b[i];
    // for (int i = 1; i < n+1;i++)
    //     cout << sum_l[i] << " ";
    // cout << nl;
    // for (int i = 1; i < n+1;i++)
    //     cout << sum_r[i] << " ";
    // cout << nl;
    for (int i = 1; i < n ;i++)
    {
        for (int j = 1; j < n;j++)
        {
            if(sum_l[i]==sum_r[j])
            {
                mid_index = i + 1;
                if(mid_index==1&&sum_r[n] == 0)
                {
                    cout << 1;
                    return 0;
                }
                else if (mid_index == n && sum_l[n-1] == 0)
                {
                    cout << n;
                    return 0;
                }
                cout << mid_index;
                return 0;
            }
        }
    }
    cout << "-1";