1899B.cpp

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

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t;
    cin >> t;
    while (t--)
    {
        int n;
        cin >> n;
        vector<ll> arr(n);
        for (int i = 0; i < n; i++)
        {
            cin >> arr[i];
        }
        ll absdif = 0;
        for (int i = 1; i <= n / 2; i++)
        {
            if (n % i == 0)
            {
                ll minimum = LONG_LONG_MAX;
                ll maximum = 0;
                ll temp = 0;
                for (int j = 0; j < n; j++)
                {
                    temp += arr[j];
                    if ((j + 1) % i == 0)
                    {
                        minimum = min(minimum, temp);
                        maximum = max(maximum, temp);
                        temp = 0;
                    }
                }
                absdif = max(absdif, maximum - minimum); 
            }
        }

        cout << absdif << '\n';
    }
    return 0;
}