PRODSUM HSGVinh Phuc L9 2015-2016

#define task "PRODSUM"

#include <iostream>
#include <cstdio>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 2e5 + 5;
int n, a[N];
ll C, b[N], Cl[N], Cr[N];

void Read()
{
    cin >> n;

    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i];
        C += 1ll * i * a[i];
        b[i] = b[i - 1] + a[i];
    }
}

void Solve()
{
    ll ans = C;

    for (int i = 1; i <= n; ++i)
    {
        Cl[i] = C + b[i - 1] - 1ll * (i - 1) * a[i];
        Cr[i] = C - (b[n] - b[i]) + 1ll * (n - i) * a[i];

        ans = max(ans, max(Cl[i], Cr[i]));
    }

    cout << ans;
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }
    Read();
    Solve();
}