Submission #7684680

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vs = vector<string>;
using pll = pair<ll, ll>;
using vp = vector<pll>;
template<class T> using V = vector<T>;
template<class T> using VV = vector<vector<T> >;
#define rep(i, n) for(ll i = 0; i < (n); i++)
#define repb(i, n) for(ll i = (n)-1; i >= 0; i--)
#define repr(i, a, b) for(ll i = (a); i < (b); i++)
#define reprb(i, a, b) for(ll i = (a)-1; i >= (b); i--)
#define ALL(a) (a).begin(), (a).end()
#define SZ(x) ((ll)(x).size())
const ll MOD = 1000000007;
const ll INF = 100000000000000000LL;
inline ll GCD(ll a, ll b){ return b?GCD(b, a % b):a; }
inline ll LCM(ll a, ll b){ return a/GCD(a, b)*b; }
inline ll powint(unsigned long long x, ll y){ ll r=1; while(y){ if(y&1) r*=x; x*=x; y>>=1; } return r; }
inline ll powmod(ll x, ll y, ll m = MOD){ ll r=1; while(y){ if(y&1) r*=x; x*=x; r%=m; x%=m; y>>=1; } return r; }
template<class S, class T>inline bool chmax(S &a, const T &b){ if(a<b) { a=b; return 1; } return 0; }
template<class S, class T>inline bool chmin(S &a, const T &b){ if(b<a) { a=b; return 1; } return 0; }
#ifdef OJ_LOCAL
#include "dump.hpp"
#else
#define dump(...) ((void)0)
#endif

vll divisor(int n){
    vll res;
    for(int i = 1; i * i <= n; i++){
        if(n % i == 0){
            res.push_back(i);
            if(i * i != n) res.push_back(n / i);
        }
    }
    sort(ALL(res));
    return res;
}

vll divk;
vi cnt;

int main(){
    cin.tie(0); ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    ll n, k;
    cin >> n >> k;
    vll a(n);
    rep(i, n){
        cin >> a[i];
        a[i] = GCD(a[i], k);
    }
    divk = divisor(k);
    cnt.resize(SZ(divk), 0);
    rep(i, n){
        rep(j, SZ(divk)){
            if(a[i] == divk[j]){
                cnt[j]++;
                break;
            }
        }
    }
    ll ans = 0;
    rep(i, SZ(divk)){
        if(cnt[i] > 0){
            rep(j, SZ(divk)){
                if(cnt[j] > 0 && (divk[i]*divk[j])%k == 0){
                    if(i == j){
                        ans += cnt[i]*(cnt[i]-1);
                    }else{
                        ans += cnt[i]*cnt[j];
                    }
                }
            }
        }
    }
    dump(cnt);
    cout << ans/2 << endl;
    return 0;
}

Submission Info

Judge Result