Language: C++

#pragma region kyomukyomupurin

/**
 *    author  : 𝒌𝒚𝒐𝒎𝒖𝒌𝒚𝒐𝒎𝒖𝒑𝒖𝒓𝒊𝒏
 *    created : 2020-06-15 13:52:36
 **/

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

using namespace std;

using int64 = long long;

template<class T>
inline void eraque(std::vector<T>& vec) {
  vec.erase(std::unique(vec.begin(), vec.end()), vec.end());
  return;
}

template<class T>
inline int lower_position(const std::vector<T>& vec, T value) {
  return static_cast<int>(distance(vec.begin(), std::lower_bound(vec.begin(), vec.end(), value)));
}

template<class T>
inline int upper_position(const std::vector<T>& vec, T value) {
  return static_cast<int>(distance(vec.begin(), std::upper_bound(vec.begin(), vec.end(), value)));
}

template <class T>
using binary_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;

template <class T, class U>
std::ostream& operator<<(std::ostream& os, const std::pair<T, U>& p) {
  return os << '(' << p.first << ", " << p.second << ')';
}

#if __cplusplus >= 201703L
template <class Ch, class Tr, class Tuple, std::size_t... Is>
void tuple_out(std::basic_ostream<Ch, Tr>& os, const Tuple& tp, std::index_sequence<Is...>) {
  ((os << (Is ? ", " : "(") << std::get<Is>(tp)), ...) << ")";
}

template <class Ch, class Tr, class... Args>
auto& operator<<(std::basic_ostream<Ch, Tr>& os, const std::tuple<Args...>& tp) {
  tuple_out(os, tp, std::index_sequence_for<Args...>{});
  return os;
}
#endif

template <class T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& vec) {
  int n = 0;
  for (auto e : vec) os << (n++ ? ", " : "{") << e;
  return os << (n ? "}" : "{}");
}

template <class T, class Compare>
std::ostream& operator<<(std::ostream& os, const std::set<T, Compare>& st) {
  int n = 0;
  for (auto e : st) os << (n++ ? ", " : "{") << e;
  return os << (n ? "}" : "{}");
}

template <class T, class U, class Compare>
std::ostream& operator<<(std::ostream& os, const std::map<T, U, Compare>& mp) {
  int n = 0;
  for (auto e : mp) os << (n++ ? ", " : "{") << e;
  return os << (n ? "}" : "{}");
}

template <class T>
std::istream& operator>>(std::istream& is, std::vector<T>& vec) {
  for (T& e : vec) is >> e;
  return is;
}

template <class T, class U>
std::istream& operator>>(std::istream& is, std::pair<T, U>& p) {
  return is >> p.first >> p.second;
}

#if __cplusplus >= 201703L
template <class Tuple, std::size_t... Is>
void tuple_in(std::istream& is, Tuple& tp, std::index_sequence<Is...>) {
  ((is >> std::get<Is>(tp)), ...);
}

template <class... Args>
std::istream& operator>>(std::istream& is, std::tuple<Args...>& tp) {
  tuple_in(is, tp, std::index_sequence_for<Args...>{});
  return is;
}
#endif

#define all(_) begin(_), end(_)
#define rall(_) rbegin(_), rend(_)

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

void debug_out() { std::cerr << '\n'; }

template <class Head, class... Tail>
void debug_out(Head&& head, Tail&&... tail) {
  std::cerr << head;
  if (sizeof...(Tail) != 0) std::cerr << ", ";
  debug_out(std::forward<Tail>(tail)...);
}

#pragma endregion kyomukyomupurin

using int128 = __int128_t;

int128 power(int128 base, int128 e, int128 mod) {
  int128 res = 1;
  base %= mod;
  while (e) {
    if (e & 1) (res *= base) %= mod;
    (base *= base) %= mod;
    e >>= 1;
  }
  return res;
}

bool is_prime(int64 n) {
  if (n < 2 || ~n & 1) return n == 2;
  int s = __builtin_ctzll(n - 1);
  int64 d = (n - 1) >> s;
  for (int64 base : {2, 325, 9375, 28178, 450775, 9780504, 1795265022}) {
    int128 x = base % n;
    if (!x) continue;
    x = power(x, d, n);
    if (x == 1 || x == n - 1) continue;
    bool ok = false;
    for (int i = 0; i < s - 1; ++i) {
      (x *= x) %= n;
      if (x == n - 1) {
        ok = true; break;
      }
    }
    if (!ok) return false;
  }
  return true;
}

int64 fast_gcd(int64 x, int64 y) {
  if (x < 0) x = -x;
  if (y < 0) y = -y;
  if (!x) return y;
  if (!y) return x;
  int s = __builtin_ctzll(x | y);
  x >>= __builtin_ctzll(x);
  do {
    y >>= __builtin_ctzll(y);
    if (x > y) std::swap(x, y);
    y -= x;
  } while (y);
  return x << s;
}

template <class T>
inline std::vector<T> connect(const std::vector<T> &a,
                              const std::vector<T> &b) {
  std::vector<T> c(a.size() + b.size());
  std::merge(a.begin(), a.end(), b.begin(), b.end(), c.begin());
  return c;
}

template <class T>
std::vector<T> factor(T n) {
  if (n <= 1) return {};
  if (is_prime(n)) return {n};
  if (~n & 1) return connect({2}, factor(n >> 1));
  for (T c = 1;; ++c) {
    T x = 2, y = 2, d;
    do {
      x = ((int128)x * x + c) % n;
      y = ((int128)y * y + c) % n;
      y = ((int128)y * y + c) % n;
      d = fast_gcd(x - y, n);
    } while (d == 1);
    if (d < n) return connect(factor(d), factor(n / d));
  }
}

template <class T>
std::vector<T> divisor(T n) {
  std::vector<T> v1 = factor(n);
  auto v2 = RunLengthEncoding(v1);
  std::vector<T> div;
  int sz = v2.size();
  auto dfs = [&](auto&& self, T val, int d) -> void {
    if (d == sz) {
      div.emplace_back(val);
      return;
    }
    int cur = 1;
    auto [pr, cnt] = v2[d];
    for (int i = 0; i < cnt + 1; ++i, cur *= pr) {
      self(self, val * cur, d + 1);
    }
  };
  dfs(dfs, 1, 0);
  std::sort(div.begin(), div.end());

  return div;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int n; cin >> n;
  vector<int> a(n); cin >> a;

  vector<int> cnt(1010101, 0);
  for (int e : a) ++cnt[e];

  int ans = 0;

  for (int i = 0; i < n; ++i) {
    vector<int> dv = divisor(a[i]);
    bool ok = true;
    for (int e : dv) {
      if (e == a[i]) {
        ok &= (cnt[e] <= 1);
      } else {
        ok &= (cnt[e] < 1);
      }
    }
    ans += ok;
  }

  cout << ans << endl;

  return 0;
}


Compiler output:
a.cc: In instantiation of 'std::vector<_Tp> divisor(T) [with T = int]':
a.cc:245:29:   required from here
  245 |     vector<int> dv = divisor(a[i]);
      |                      ~~~~~~~^~~~~~
a.cc:212:30: error: 'RunLengthEncoding' was not declared in this scope
  212 |   auto v2 = RunLengthEncoding(v1);
      |             ~~~~~~~~~~~~~~~~~^~~~