Problem p02642 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; i++)
#define ll long long
using namespace std;
// typedef vector<unsigned int>vec;
// typedef vector<ll>vec;
// typedef vector<vec> mat;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int INF = 1000000000;
const ll LINF = 1000000000000000000; // 1e18
const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const double PI = acos(-1.0);
const double EPS = 1e-10;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
// template<class T> inline void add(T &a, T b){a = ((a+b) % MOD + MOD) % MOD;};

vector<ll> divisor(ll n) {
  vector<ll> res;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.push_back(i);
      if (i != n / i)
        res.push_back(n / i);
    }
  }
  return res;
}

void solve() {
  int N;
  cin >> N;
  vector<int> A(N);
  vector<int> mp(202020);
  REP(i, N) {
    cin >> A[i];
    mp[A[i]]++;
  }
  int ans = 0;
  REP(k, N) {
    mp[A[k]]--;
    bool ok = true;
    for (ll i = 1; i * i <= A[k]; i++) {
      if (A[k] % i == 0) {
        if (mp[i] > 0) {
          ok = false;
        }
        if (i != A[i] / i)
          if (mp[A[k] / i] > 0) {
            ok = false;
          }
      }
      if (!ok)
        break;
    }
    if (ok) {
      // cout << k << endl;
      ans++;
    }
    mp[A[k]]++;
  }
  cout << ans << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  // int T; cin >> T; REP(t,T) solve();
}

Fixed submission:
#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; i++)
#define ll long long
using namespace std;
// typedef vector<unsigned int>vec;
// typedef vector<ll>vec;
// typedef vector<vec> mat;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int INF = 1000000000;
const ll LINF = 1000000000000000000; // 1e18
const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const double PI = acos(-1.0);
const double EPS = 1e-10;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
// template<class T> inline void add(T &a, T b){a = ((a+b) % MOD + MOD) % MOD;};

vector<ll> divisor(ll n) {
  vector<ll> res;
  for (ll i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.push_back(i);
      if (i != n / i)
        res.push_back(n / i);
    }
  }
  return res;
}

void solve() {
  int N;
  cin >> N;
  vector<int> A(N);
  vector<int> mp(2020202);
  REP(i, N) {
    cin >> A[i];
    mp[A[i]]++;
  }
  int ans = 0;
  REP(k, N) {
    mp[A[k]]--;
    bool ok = true;
    for (ll i = 1; i * i <= A[k]; i++) {
      if (A[k] % i == 0) {
        if (mp[i] > 0) {
          ok = false;
        }
        if (i != A[i] / i)
          if (mp[A[k] / i] > 0) {
            ok = false;
          }
      }
      if (!ok)
        break;
    }
    if (ok) {
      // cout << k << endl;
      ans++;
    }
    mp[A[k]]++;
  }
  cout << ans << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  // int T; cin >> T; REP(t,T) solve();
}