Submission #1993384

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Source Code Expand

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

int main()
{
    int n, k; cin>>n>>k;
    vector<int> a(n);
    for(auto& e: a) cin>>e;

    unordered_map<long, long> d;
    for(auto& e: a) ++d[__gcd(e, k)];

    long res=0;
    for(auto& p: d) {
        for(auto& q: d) {
            auto x=p.first;
            auto y=q.first;
            if (x*y%k) continue;
            res+=p.second*q.second;
            if (x==y) res-=q.second;
        }
    }
    cout<<res/2<<endl;
}

Submission Info

Judge Result