#1187637 (C++23) No.3717 GCD LCM GCD

• 問題: No.3717 GCD LCM GCD
• ユーザー: HoyHoyCharhang
• 提出日時: 2026-09-18 22:24:39
• 言語: C++23 (gcc 15.3.0 + boost 1.92.0 + ACL)
• 結果: AC
• 実行時間: 63 ms / 2,000 ms
• コード長: 3,408 bytes
• コンパイル時間: 2,436 ms
• コンパイル使用メモリ: 352,748 KB
• 実行使用メモリ: 11,316 KB
• 最終ジャッジ日時: 2026-09-18 22:24:47
• 合計ジャッジ時間: 4,126 ms
• ジャッジサーバーID （参考情報）: judge3_0 / judge2_0

ファイルパターン	結果
sample	AC * 4
other	AC * 8

ソースコード

#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,s,n) for (int i = (s); i < (n); ++i)
#define rrep(i,g,n) for (int i = (n)-1; i >= (g); --i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define len(x) (int)(x).size()
#define dup(x,y) (((x)+(y)-1)/(y))
#define pb push_back
#define eb emplace_back
#define Field(T) vector<vector<T>>
using namespace std;
using ll = long long;
using ull = unsigned long long;
template<typename T> using pq = priority_queue<T,vector<T>,greater<T>>;
using P = pair<int,int>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}

template< int mod >
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt &operator+=(const ModInt &p) {
    if((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (int) (1LL * x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }

  ModInt inverse() const {
    assert(x);
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }

  ModInt pow(int64_t n) const {
    ModInt ret(1), mul(x);
    while(n > 0) {
      if(n & 1) ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }

  friend ostream &operator<<(ostream &os, const ModInt &p) {
    return os << p.x;
  }

  friend istream &operator>>(istream &is, ModInt &a) {
    int64_t t;
    is >> t;
    a = ModInt< mod >(t);
    return (is);
  }

  static int get_mod() { return mod; }
};

using mint = ModInt<998244353>;

template<typename T>
vector<T> smallest_prime_factors(T n) {
  vector<T> spf(n+1);
  for (int i = 0; i <= n; ++i) spf[i] = i;
  for (T i = 2; i * i <= n; ++i) {
    if (spf[i] == i) {
      for (T j = i * i; j <= n; j += i) {
        if (spf[j] == j) spf[j] = i;
      }
    }
  }
  return spf;
}

vector<P> factorization(int x, vector<int> &spf) {
  vector<P> ret;
  while (x != 1) {
    if (ret.empty() || ret.back().fi != spf[x]) {
      ret.emplace_back(spf[x], 1);
    } else {
      ret.back().se++;
    }
    x /= spf[x];
  }
  return ret;
}

int main() {
  int n, k;
  cin >> n >> k;
  int s = (n/k)*(k-1)+(n%k);
  // cout << s << endl;z
  vector<int> spf = smallest_prime_factors(1000010);
  vector<int> a(n);
  rep(i,0,n) cin >> a[i];
  map<int,vector<int>> mp;
  rep(i,0,n) {
    vector<P> fs = factorization(a[i], spf);
    for (auto [p, e] : fs) {
      mp[p].eb(e);
    }
  }
  mint ans = 1;
  for (auto &[p, v] : mp) {
    sort(rall(v));
    if (len(v) > s) {
      ans *= mint(p).pow(v[s]);
    }
  }
  cout << ans << endl;
  return 0;
}