Problem p02642 (C++)

Buggy submission (status: Time Limit Exceeded):
#define _USE_MATH_DEFINES
#include <algorithm>
#include <array>
#include <bitset>
#include <climits>
#include <cmath>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <stdio.h>
#include <string.h>
#include <string>
#include <time.h>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#define lnd '\n'
// #define reverse(i, n) for(ll i = n-1; i >= 0; --i)
#define from(i, n) for (ll i = 0; i < n; ++i)
#define loop(i, n) for (ll i = 0; i < n; i++)
#define REPN(i, n) for (ll i = 1; i <= n; ++i)
#define ALL(s) (s).begin(), (s).end()
#define rALL(s) (s).rbegin(), (s).rend()
#define sz(s) (int)(s).size()
#define mk make_pair
#define pb push_back
#define sqr(s) ((s) * (s))

using namespace std;

typedef long long ll;
typedef long long int lli;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int ui;

template <class T> T GCD(T a, T b) {
  if (a == 0)
    return b;
  return GCD(b % a, a);
}

template <class T> T LCM(T a, T b) { return a * b / GCM(a, b); }

template <class T> T modpow(T x, T p) {
  T res = 1;
  while (p > 0) {
    if (p & 1)
      res *= x;
    x *= x;
    p /= 2;
  }
  return res;
}

template <class T> T modpow(T x, T p, ll mod) {
  T res = 1;
  while (p > 0) {
    if (p & 1)
      res = (res * x) % mod;
    x = (x * x) % mod;
    p /= 2;
  }
  return res % mod;
}

template <class T> void print(T a[], ll n) {
  for (ll i = 0; i < n; i++)
    std::cout << a[i] << ' ';
  cout << endl;
}

template <class T> void printc(T c) {
  for (auto const &v : c)
    std::cout << v << ' ';
  cout << endl;
}

struct HASH {
  size_t operator()(const pair<long, long> &x) const {
    return hash<long long>()(((long long)x.first) ^
                             (((long long)x.second) << 32));
  }
};

bool pair_sort(const pair<int, int> &p1, const pair<int, int> &p2) {
  if (p1.first != p2.first)
    return p1.first < p2.first;
  else
    return p1.second < p2.second;
}

const int INF = std::numeric_limits<int>::max();
const ll M_INF = std::numeric_limits<ll>::min();
const ll LL_INF = std::numeric_limits<ll>::max();

void solution();
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solution();
  return 0;
}

void solution() {
  ll n;
  cin >> n;

  ll m = 1e6 + 1;
  vector<ll> b(m, 0);
  vector<ll> a(n);
  loop(i, n) {
    cin >> a[i];
    b[a[i]] = 1;
  }

  for (auto i : a) {
    for (ll j = i; j < m; j += i) {
      b[j]++;
    }
  }

  ll count = 0;
  for (ll i = 0; i < n; i++) {
    if (b[a[i]] == 2) {
      count++;
    }
  }

  cout << count << endl;
}


Fixed submission:
#define _USE_MATH_DEFINES
#include <algorithm>
#include <array>
#include <bitset>
#include <climits>
#include <cmath>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <stdio.h>
#include <string.h>
#include <string>
#include <time.h>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#define lnd '\n'
// #define reverse(i, n) for(ll i = n-1; i >= 0; --i)
#define from(i, n) for (ll i = 0; i < n; ++i)
#define loop(i, n) for (ll i = 0; i < n; i++)
#define REPN(i, n) for (ll i = 1; i <= n; ++i)
#define ALL(s) (s).begin(), (s).end()
#define rALL(s) (s).rbegin(), (s).rend()
#define sz(s) (int)(s).size()
#define mk make_pair
#define pb push_back
#define sqr(s) ((s) * (s))

using namespace std;

typedef long long ll;
typedef long long int lli;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int ui;

template <class T> T GCD(T a, T b) {
  if (a == 0)
    return b;
  return GCD(b % a, a);
}

template <class T> T LCM(T a, T b) { return a * b / GCM(a, b); }

template <class T> T modpow(T x, T p) {
  T res = 1;
  while (p > 0) {
    if (p & 1)
      res *= x;
    x *= x;
    p /= 2;
  }
  return res;
}

template <class T> T modpow(T x, T p, ll mod) {
  T res = 1;
  while (p > 0) {
    if (p & 1)
      res = (res * x) % mod;
    x = (x * x) % mod;
    p /= 2;
  }
  return res % mod;
}

template <class T> void print(T a[], ll n) {
  for (ll i = 0; i < n; i++)
    std::cout << a[i] << ' ';
  cout << endl;
}

template <class T> void printc(T c) {
  for (auto const &v : c)
    std::cout << v << ' ';
  cout << endl;
}

struct HASH {
  size_t operator()(const pair<long, long> &x) const {
    return hash<long long>()(((long long)x.first) ^
                             (((long long)x.second) << 32));
  }
};

bool pair_sort(const pair<int, int> &p1, const pair<int, int> &p2) {
  if (p1.first != p2.first)
    return p1.first < p2.first;
  else
    return p1.second < p2.second;
}

const int INF = std::numeric_limits<int>::max();
const ll M_INF = std::numeric_limits<ll>::min();
const ll LL_INF = std::numeric_limits<ll>::max();

void solution();
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solution();
  return 0;
}

void solution() {
  ll n;
  cin >> n;

  ll m = 1e6 + 1;
  vector<ll> b(m, 0);
  vector<ll> a(n);
  loop(i, n) {
    cin >> a[i];
    b[a[i]] = 1;
  }

  for (auto i : a) {
    if (b[i] >= 2) {
      b[i]++;
      continue;
    }
    for (ll j = i; j < m; j += i) {
      b[j]++;
    }
  }

  ll count = 0;
  for (ll i = 0; i < n; i++) {
    if (b[a[i]] == 2) {
      count++;
    }
  }

  cout << count << endl;
}