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

// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
template <typename T> using V = vector<T>;
template <typename T> using VV = vector<vector<T>>;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(v) (v).begin(), (v).end()
#define siz(v) (ll)(v).size()
#define rep(i, a, n) for (ll i = a; i < (ll)(n); ++i)
#define repr(i, a, n) for (ll i = n - 1; (ll)a <= i; --i)
#define ENDL '\\n'
typedef pair<int, int> Pi;
typedef pair<ll, ll> PL;
constexpr ll mod = 1000000007; // 998244353;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 + 99);
const ld PI = acos((ld)-1);
const vector<ll> dx = {-1, 1, 0, 0}, dy = {0, 0, -1, 1};
template <typename T, typename U> inline bool chmin(T &t, const U &u) {
  if (t > u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T, typename U> inline bool chmax(T &t, const U &u) {
  if (t < u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T> inline T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }

template <typename T, typename Y> inline T mpow(T a, Y n) {
  T res = 1;
  for (; n; n >>= 1) {
    if (n & 1)
      res = res * a;
    a = a * a;
  }
  return res;
}

template <typename T, typename Y>
ostream &operator<<(ostream &os, const pair<T, Y> &p) {
  return os << "{" << p.fs << "," << p.sc << "}";
}
template <typename T> ostream &operator<<(ostream &os, const V<T> &v) {
  os << "{";
  for (auto e : v)
    os << e << ",";
  return os << "}";
}
template <typename... Args> void debug(Args &...args) {
  for (auto const &x : {args...}) {
    cerr << x << ' ';
  }
  cerr << ENDL;
}

set<ll> prime;
bool pc = true;

std::vector<ll> sieve(int n) {
  std::vector<ll> res(n);
  std::iota(res.begin(), res.end(), 0);
  for (int i = 2; i * i < n; ++i) {
    if (res[i] < i)
      continue;
    for (int j = i * i; j < n; j += i)
      if (res[j] == j)
        res[j] = i;
  }
  return res;
}

std::vector<ll> factor(int n, const std::vector<ll> &min_factor) {
  // min_factor は sieve() で得られたものとする
  std::vector<ll> res;
  while (n > 1) {
    res.push_back(min_factor[n]);
    n /= min_factor[n];
    // 割った後の値についても素因数を知っているので順次求まる
  }
  return res;
}

signed main() {
  cin.tie(0);
  cerr.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  ll n;
  cin >> n;

  V<ll> v(n), er = sieve(1000010ll);
  rep(i, 0, n) cin >> v[i];
  ll g = v[0];
  rep(i, 1, n) g = gcd(g, v[i]);

  rep(i, 0, n) {
    V<ll> ps = factor(v[i], er);
    sort(all(ps));
    ps.erase(unique(all(ps)), ps.end());

    rep(j, 0, siz(ps)) {
      if (prime.count(ps[j]))
        pc = false;
      else
        prime.insert(ps[j]);
    }
  }

  if (pc)
    cout << "pairwise coprime" << ENDL;
  else if (g == 1)
    cout << "setwise coprime" << ENDL;
  else
    cout << "not coprime" << ENDL;
}
//! ( . _ . ) !
// CHECK overflow,vector_size,what to output?

Error: TLE

Fixed submission:

// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
template <typename T> using V = vector<T>;
template <typename T> using VV = vector<vector<T>>;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(v) (v).begin(), (v).end()
#define siz(v) (ll)(v).size()
#define rep(i, a, n) for (ll i = a; i < (ll)(n); ++i)
#define repr(i, a, n) for (ll i = n - 1; (ll)a <= i; --i)
#define ENDL '\\n'
typedef pair<int, int> Pi;
typedef pair<ll, ll> PL;
constexpr ll mod = 1000000007; // 998244353;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 + 99);
const ld PI = acos((ld)-1);
const vector<ll> dx = {-1, 1, 0, 0}, dy = {0, 0, -1, 1};
template <typename T, typename U> inline bool chmin(T &t, const U &u) {
  if (t > u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T, typename U> inline bool chmax(T &t, const U &u) {
  if (t < u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T> inline T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }

template <typename T, typename Y> inline T mpow(T a, Y n) {
  T res = 1;
  for (; n; n >>= 1) {
    if (n & 1)
      res = res * a;
    a = a * a;
  }
  return res;
}

template <typename T, typename Y>
ostream &operator<<(ostream &os, const pair<T, Y> &p) {
  return os << "{" << p.fs << "," << p.sc << "}";
}
template <typename T> ostream &operator<<(ostream &os, const V<T> &v) {
  os << "{";
  for (auto e : v)
    os << e << ",";
  return os << "}";
}
template <typename... Args> void debug(Args &...args) {
  for (auto const &x : {args...}) {
    cerr << x << ' ';
  }
  cerr << ENDL;
}

template <typename T> vector<T> get_prime_factor(T x) { // 素因数の種類だけを返す
  vector<T> res(0);
  for (ll i = 2; i * i <= x; i++) {
    if (x % i == 0)
      res.push_back(i);

    while (x % i == 0) {
      x /= i;
    }
  }
  if (x != 1)
    res.push_back(x); // xが素数だった時用
  return res;
}

signed main() {
  cin.tie(0);
  cerr.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  ll n;
  cin >> n;

  V<ll> v(n);
  rep(i, 0, n) cin >> v[i];
  ll g = v[0];
  rep(i, 1, n) g = gcd(g, v[i]);

  bool pc = true;
  set<int> se;
  rep(i, 0, n) {
    V<ll> ps = get_prime_factor(v[i]);
    rep(j, 0, siz(ps)) {
      if (se.count(ps[j]))
        pc = false;
      else
        se.insert(ps[j]);
    }
  }

  if (pc)
    cout << "pairwise coprime" << ENDL;
  else if (g == 1)
    cout << "setwise coprime" << ENDL;
  else
    cout << "not coprime" << ENDL;
}
//! ( . _ . ) !
// CHECK overflow,vector_size,what to output?