📦 ved015 / Codeforces-solution

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30#include<iostream>
#include<map>
using namespace std;

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n, m;
        cin >> n >> m;
        map<int, int> cnt;
        while (n--) {
            int x;
            cin >> x;
            cnt[x % m]++;
        }
        int ans = 0;
        for (auto &c : cnt) {
            if (c.first == 0) ans++;
            else if (2 * c.first == m) {
                ans++;
            } else if (2 * c.first < m || cnt.find(m - c.first) == cnt.end()) {
                int x = c.second, y = cnt[m - c.first];
                ans += 1 + max(0, abs(x - y) - 1);
            }
        }
        cout << ans << '\n';
    }
    return 0;
}