Equal

• Time : O(n)
• Space : O(1)

long long equal(vector<int> arr) {
    vector<long long> req(5);
    long long mi = *min_element(begin(arr), end(arr));
    // make minimum - 0 to minimum - 4 and get minimin operations
    for(int i = 0; i < 5; i++) {
        for(auto& a : arr) {
            long long d = a - mi;
            long long five = 0, two = 0, one = 0;
            five = d / 5; d -= 5 * five;
            two = d / 2; d -= 2 * two;
            one = d;
            req[i] += five + two + one;
        }
        mi--;
    }
    return *min_element(begin(req), end(req));
}