Problem p00654 (C++) — buggy submission, verdict: Time Limit Exceeded

#include "bits/stdc++.h"
#pragma warning(disable : 4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

#include <unordered_map>

const int mod = 998244353;
struct Mod {
public:
  int num;
  Mod() : Mod(0) { ; }
  Mod(long long int n) : num((n % mod + mod) % mod) {
    static_assert(mod < INT_MAX / 2,
                  "mod is too big, please make num 'long long int' from 'int'");
  }
  Mod(int n) : Mod(static_cast<long long int>(n)) { ; }
  operator int() { return num; }
};

Mod operator+(const Mod a, const Mod b) { return Mod((a.num + b.num) % mod); }
Mod operator+(const long long int a, const Mod b) { return Mod(a) + b; }
Mod operator+(const Mod a, const long long int b) { return b + a; }
Mod operator++(Mod &a) { return a + Mod(1); }
Mod operator-(const Mod a, const Mod b) {
  return Mod((mod + a.num - b.num) % mod);
}
Mod operator-(const long long int a, const Mod b) { return Mod(a) - b; }
Mod operator--(Mod &a) { return a - Mod(1); }
Mod operator*(const Mod a, const Mod b) {
  return Mod(((long long)a.num * b.num) % mod);
}
Mod operator*(const long long int a, const Mod b) { return Mod(a) * b; }
Mod operator*(const Mod a, const long long int b) { return Mod(b) * a; }
Mod operator*(const Mod a, const int b) { return Mod(b) * a; }
Mod operator+=(Mod &a, const Mod b) { return a = a + b; }
Mod operator+=(long long int &a, const Mod b) { return a = a + b; }
Mod operator-=(Mod &a, const Mod b) { return a = a - b; }
Mod operator-=(long long int &a, const Mod b) { return a = a - b; }
Mod operator*=(Mod &a, const Mod b) { return a = a * b; }
Mod operator*=(long long int &a, const Mod b) { return a = a * b; }
Mod operator*=(Mod &a, const long long int &b) { return a = a * b; }
Mod operator^(const Mod a, const int n) {
  if (n == 0)
    return Mod(1);
  Mod res = (a * a) ^ (n / 2);
  if (n % 2)
    res = res * a;
  return res;
}
Mod mod_pow(const Mod a, const long long int n) {
  if (n == 0)
    return Mod(1);
  Mod res = mod_pow((a * a), (n / 2));
  if (n % 2)
    res = res * a;
  return res;
}

Mod inv(const Mod a) { return a ^ (mod - 2); }
Mod operator/(const Mod a, const Mod b) {
  assert(b.num != 0);
  return a * inv(b);
}
Mod operator/(const long long int a, const Mod b) { return Mod(a) / b; }
Mod operator/=(Mod &a, const Mod b) { return a = a / b; }

#define MAX_MOD_N 10240

Mod fact[MAX_MOD_N], factinv[MAX_MOD_N];
void init(const int amax = MAX_MOD_N) {
  fact[0] = Mod(1);
  factinv[0] = 1;
  for (int i = 0; i < amax - 1; ++i) {
    fact[i + 1] = fact[i] * Mod(i + 1);
    factinv[i + 1] = factinv[i] / Mod(i + 1);
  }
}
Mod comb(const int a, const int b) {
  return fact[a] * factinv[b] * factinv[a - b];
}

vector<vector<int>> flag(1001, vector<int>(1001));

Mod solve(int rest, int now, vector<vector<Mod>> &memo,
          const vector<int> &nums) {
  if (!flag[rest][now]) {
    flag[rest][now] = true;
    if (now == 1) {
      return memo[rest][now] = 1;
    } else {

      Mod ans = 0;
      Mod mo = 1;
      for (int k = 0; k <= rest / now; ++k) {

        ans += solve(rest - k * now + nums[now - 1], now - 1, memo, nums) * mo;
        mo = mo * comb(rest - k * now, now);
        mo = mo / Mod(k + 1);
      }

      return memo[rest][now] = ans;
    }
  } else {
    return memo[rest][now];
  }
}
int main() {
  while (true) {

    int N;
    cin >> N;
    if (!N)
      break;
    vector<long long int> odds, as;
    for (int i = 0; i < N * (N + 1) / 2; ++i) {
      long long int a;
      cin >> a;
      if (a % 2)
        odds.push_back(a);
      else
        as.push_back(a);
    }
    sort(odds.begin(), odds.end());
    sort(as.begin(), as.end());

    long long int ans = round(
        sqrt(ld(as[as.size() - 1]) * as[as.size() - 2] / odds.back()) + eps);

    vector<long long int> ans2;
    for (int i = 0; i < N; ++i) {
      ans2.push_back(as[i] / ans);
    }
    cout << ans << endl;
    for (int i = 0; i < N; ++i) {
      cout << ans2[i];
      if (i == N - 1)
        cout << endl;
      else
        cout << " ";
    }
  }

  return 0;
}


Error: TLE

Fixed submission:

#include "bits/stdc++.h"
#include <unordered_map>
#include <unordered_set>
#pragma warning(disable : 4996)
using namespace std;
vector<long long int> divisor(long long int n) {
  vector<long long int> res;
  for (long long int i = 1; i * i <= n; ++i) {
    if (n % i == 0) {
      res.push_back(i);
      if (i * i != n)
        res.push_back(n / i);
    }
  }
  sort(begin(res), end(res));
  return res;
}
long long int gcd(long long int l, long long int r) {
  if (l > r)
    return gcd(r, l);
  else {
    if (r % l) {
      return gcd(l, r % l);

    } else {
      return l;
    }
  }
}

int main() {
  while (1) {
    int N;
    cin >> N;
    if (!N)
      break;
    vector<long long int> v;
    long long int agcd = 0;
    for (int i = 0; i < N * (N + 1) / 2; ++i) {
      long long int a;
      cin >> a;
      v.push_back(a);
      if (!(a % 2)) {
        if (agcd) {
          agcd = gcd(agcd, a);
        } else {
          agcd = a;
        }
      }
    }
    sort(v.begin(), v.end());
    auto divs(divisor(agcd));
    bool flag = true;
    for (auto d : divs) {
      if (!flag)
        break;
      if (d % 2)
        continue;
      vector<long long int> nans(1, d);
      bool ok = true;
      for (const auto a : v) {
        if (a % 2 == 0) {
          nans.push_back(a / d);
          if (nans.back() % 2 == 0)
            ok = false;
          if (nans.back() > INT_MAX)
            ok = false;
        }
      }
      if (!ok)
        continue;
      sort(nans.begin(), nans.end());
      vector<long long int> nv;
      for (int i = 0; i < nans.size(); ++i) {
        for (int j = i + 1; j < nans.size(); ++j) {
          nv.emplace_back(nans[i] * nans[j]);
        }
      }
      sort(nv.begin(), nv.end());
      if (v == nv) {
        const auto evit(
            find_if(nans.begin(), nans.end(), [](const long long int n) {
              return n % 2 == 0;
            }));
        const long long int evnum(*evit);
        nans.erase(evit);
        cout << evnum << endl;
        for (int i = 0; i < nans.size(); ++i) {
          cout << nans[i];
          if (i == nans.size() - 1)
            cout << endl;
          else
            cout << " ";
        }
        flag = false;
      }
    }
  }
  return 0;
}