圆形牛棚

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;

const int N = 1e6 + 3;

int a[N];

void solve(){
    int n; cin >> n;
    LL sum = 0;
    for(int i = 1; i <= n; i ++){
        cin >> a[i]; a[i + n] = a[i];
        sum += a[i] * (i - 1);
    }
    for(int i = 1; i <= 2 * n; i ++) a[i] += a[i - 1];
    LL ans = 0x3f3f3f3f;
    for(int i = n + 1; i <= 2 * n; i ++){
        sum = sum + n * (a[i] - a[i - 1]) - (a[i] - a[i - n]);
        ans = min(ans, sum);
    }
    cout << ans << endl;
}

int main(){
    solve();
    return 0;
}