If its through hackkerank, why only cpp?

what are the prizes?

Good questions. In 3rd question, why my Binary indexed tree approach gives TLE? Question MySolution

Interesting problems bro. Hope you organise these contests regularly :)

Good idea for E, I really forgot that the bits were just being flipped. I think the time complexity can be improved though. Instead of a Fenwick tree, just a simple set<pair<int, int>> can be used to store the endpoints of continuous segments of ones. To find which segment containing some index, just find the segment with the closest left endpoint to that index, and check if the right endpoint is on the right of that endpoint.

Nice problems,very well balanced in my opinion. Just one question, what would be the approximate ratings of each of the problems according to codeforces standard? TIA.

I am very sorry but i am stuggling with B question in this contest for hours, i am unable to find the mistake in my code (i am ashamed of this), please help me . Code is here ----->

#include <bits/stdc++.h>
#define int long long
#define MAX 1000000
#define deb(x) cout << #x << "=" << x << endl;
using namespace std;

vector<int> phi(MAX + 5);

signed main() {
    phi[1] = 1;
    for (int i = 2; i <= MAX; i++) {
        phi[i] = i;
    }
    for (int i = 2; i * i <= MAX; i++) {
        if (phi[i] == i) {
            phi[i] = i - 1;
            for (int j = i + i; j <= MAX; j += i) {
                phi[j] -= (phi[j]/i);
            }
        }
    }

    int sum = 0;
    for (int i = 1; i <= MAX; i++) {
        sum += phi[i];
        phi[i] = sum;
        phi[i] = (2LL * phi[i]) - 1;
    }

    int q, ans = 0;
    cin >> q;
    while (q--) {
        int n;
        cin >> n;
        int temp = phi[n];
        ans += temp;
    }
    cout << ans;

    return 0;
}

I am getting wrong answer in 4 test cases for problem B( GCD Table ), can someone help me ? . Link to my code