Problem p02574 (C++) — buggy submission, verdict: Time Limit Exceeded

#define LOCAL

#undef _GLIBCXX_DEBUG

#include <bits/stdc++.h>
using namespace std;

#define IOS                                                                    \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0)
#define all(x) x.begin(), x.end()
#define ff first
#define ss second
#define MOD 1000000007LL
#define LLINF 100000000000000005LL
#define INF (int)1e9 + 1
#define pb push_back

// Copied from Gennady-Korotkevich's template

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}\\n";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}\\n";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

template <typename A, typename B, typename C, typename D, typename E>
string to_string(tuple<A, B, C, D, E> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + "," +
         to_string(get<4>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...)                                                             \\
  cerr << "\\n[" << #__VA_ARGS__ << "]:\\n", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

// End of Gennady-Korotkevich's template

using llong = long long;
using PII = pair<int, int>;

int gcd(int a, int b) { return (b == 0) ? a : gcd(b, a % b); }

int main() {
  IOS;
  vector<bool> isPrime(1000001);
  vector<int> primes;
  for (int i = 2; i <= 1000000; i++) {
    if (isPrime[i] == 0) {
      primes.push_back(i);
      for (int j = i * 2; j <= 1000000; j += i) {
        isPrime[j] = 1;
      }
    }
  }
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++)
    cin >> a[i];
  int GCD = a[0];
  for (int i = 1; i < n; i++)
    GCD = gcd(GCD, a[i]);
  if (GCD != 1) {
    cout << "not coprime";
    return 0;
  }
  set<int> s;
  for (int i = 0; i < n; i++) {
    int curNum = a[i];
    for (int j = 0; primes[j] * primes[j] <= a[i]; j++) {
      if (curNum % primes[j] == 0) {
        if (s.count(primes[j])) {
          cout << "setwise coprime";
          return 0;
        }
        s.insert(primes[j]);
        while (1) {
          curNum /= primes[j];
          if (curNum % primes[j] != 0)
            break;
        }
      }
    }
    if (curNum != 1) {
      if (s.count(curNum)) {
        cout << "setwise coprime";
        return 0;
      }
      s.insert(curNum);
    }
  }
  cout << "pairwise coprime";
  return 0;
}


Error: TLE

Fixed submission:

#define LOCAL

#undef _GLIBCXX_DEBUG

#include <bits/stdc++.h>
using namespace std;

#define IOS                                                                    \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0)
#define all(x) x.begin(), x.end()
#define ff first
#define ss second
#define MOD 1000000007LL
#define LLINF 100000000000000005LL
#define INF (int)1e9 + 1
#define pb push_back

// Copied from Gennady-Korotkevich's template

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}\\n";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}\\n";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

template <typename A, typename B, typename C, typename D, typename E>
string to_string(tuple<A, B, C, D, E> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + "," +
         to_string(get<4>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...)                                                             \\
  cerr << "\\n[" << #__VA_ARGS__ << "]:\\n", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

// End of Gennady-Korotkevich's template

using llong = long long;
using PII = pair<int, int>;

int gcd(int a, int b) { return (b == 0) ? a : gcd(b, a % b); }

int main() {
  IOS;
  vector<bool> isPrime(1000001);
  vector<int> primes;
  for (int i = 2; i <= 1000000; i++) {
    if (isPrime[i] == 0) {
      primes.push_back(i);
      for (int j = i * 2; j <= 1000000; j += i) {
        isPrime[j] = 1;
      }
    }
  }
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++)
    cin >> a[i];
  int GCD = a[0];
  for (int i = 1; i < n; i++)
    GCD = gcd(GCD, a[i]);
  if (GCD != 1) {
    cout << "not coprime";
    return 0;
  }
  sort(a.begin(), a.end());
  for (int i = 0; i < primes.size(); i++) {
    if (primes[i] > a[n - 1])
      break;
    bool flag = false;
    for (int j = 0; j < n; j++) {
      if (a[j] % primes[i] == 0 && !flag)
        flag = true;
      else if (a[j] % primes[i] == 0 && flag) {
        cout << "setwise coprime";
        return 0;
      }
    }
  }
  cout << "pairwise coprime";
  return 0;
}