Problem p01795 (C++) — buggy submission, verdict: Runtime Error

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

const int mod = 1000000009;
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 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 3024000

Mod fact[MAX_MOD_N], factinv[MAX_MOD_N];
void init() {
  fact[0] = Mod(1);
  factinv[0] = 1;
  for (int i = 0; i < MAX_MOD_N - 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) {
  while (a < b) {
    cout << 1 << endl;
  }
  while (b < 0 || a < 0) {
    cout << 1 << endl;
  }
  return fact[a] * factinv[b] * factinv[a - b];
}

struct rel {
  int a;
  int b;
  int love;
};
bool operator==(const rel &l, const rel &r) {
  return l.a == r.a && l.b == r.b && l.love == r.love;
}

struct UnionFind {
  vector<int> data;
  UnionFind(int size) : data(size, -1) {}
  bool unionSet(int x, int y) {
    x = root(x);
    y = root(y);
    if (x != y) {
      if (data[y] < data[x])
        swap(x, y);
      data[x] += data[y];
      data[y] = x;
    }
    return x != y;
  }
  bool findSet(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  int size(int x) { return -data[root(x)]; }
};
vector<Mod> dp(1e6 + 1);
Mod getrest(const int rest) {
  if (rest < 0) {
    return 0;
  } else {
    if (rest % 3) {
      assert(false);
      return 0;
    } else {
      return dp[rest / 3];
    }
  }
}
int N, M;
Mod getans(const map<int, int> &mp) {
  vector<int> v;

  Mod ans = 1;
  for (auto m : mp) {
    if (m.second >= 4)
      return 0;
    else if (m.second == 1) {
    } else {
      v.emplace_back(m.second);
    }
  }
  int rest = 3 * N - accumulate(v.begin(), v.end(), 0);
  if (N < v.size())
    return 0;
  for (auto n : v) {

    // if (rest < 3 - n) {
    //	//cout << 1 << endl;
    //	return 0;
    // }
    /*	if (n == 2) {
                    ans *= rest;
            }
            else {
                    assert(n == 3);
                    ans *= 1;
            }*/
    Mod a = n == 2 ? rest : 1;
    Mod b = comb(rest, 3 - n);
    while (a != b) {
      cout << 22 << endl;
    }
    ans *= comb(rest, 3 - n);

    rest -= (3 - n);
  }
  ans *= getrest(rest);
  return ans;
}
int main() {
  dp[0] = 1;
  for (int i = 1; i <= 1000000; ++i) {
    dp[i] = dp[i - 1] * Mod(3 * i - 1) * Mod(3 * i - 2) / Mod(2);
  }
  init();
  cin >> N >> M;
  vector<rel> rels;
  vector<rel> hates;
  set<int> aset;
  for (int i = 0; i < M; ++i) {
    int a, b, c;
    cin >> a >> b >> c;
    c = !c;
    a--;
    b--;
    aset.emplace(a);
    aset.emplace(b);
    rels.push_back(rel{a, b, c});
    if (find(rels.begin(), rels.end(), rel{b, a, c}) != rels.end()) {
      // cout << "a" << endl;
      return 0;
    }
    if (find(rels.begin(), rels.end(), rel{b, a, !c}) != rels.end()) {
      // cout << "a" << endl;
      return 0;
    }
  }
  map<int, int> mp;
  int n = 0;
  for (auto s : aset) {
    mp[s] = n;
    n++;
  }
  for (auto &r : rels) {
    r.a = mp[r.a];
    r.b = mp[r.b];
  }
  UnionFind uf(aset.size());
  for (int i = 0; i < M; ++i) {
    if (rels[i].love) {
      uf.unionSet(rels[i].a, rels[i].b);
    } else {
      hates.emplace_back(rels[i]);
    }
  }
  assert(hates.size() <= 18);
  Mod ans = 0;
  for (int i = 0; i < (1 << hates.size()); ++i) {
    UnionFind nowuf(uf);
    bitset<18> bs(i);
    for (int j = 0; j < hates.size(); ++j) {

      if (bs[j]) {
        nowuf.unionSet(hates[j].a, hates[j].b);
      }
    }
    map<int, int> lovemp;
    for (int j = 0; j < aset.size(); ++j) {
      lovemp[nowuf.root(j)]++;
    }
    if (bs.count() % 2) {
      ans -= getans(lovemp);
    } else {
      ans += getans(lovemp);
    }
  }
  cout << ans << endl;
  return 0;
}

Error: 0

Fixed submission:

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

const int mod = 1000000009;
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 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 1024000

Mod fact[MAX_MOD_N], factinv[MAX_MOD_N];
void init() {
  fact[0] = Mod(1);
  factinv[0] = 1;
  for (int i = 0; i < MAX_MOD_N - 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) {
  while (a < b) {
    cout << 1 << endl;
  }
  while (b < 0 || a < 0) {
    cout << 1 << endl;
  }
  return fact[a] * factinv[b] * factinv[a - b];
}

struct rel {
  int a;
  int b;
  int love;
};
bool operator==(const rel &l, const rel &r) {
  return l.a == r.a && l.b == r.b && l.love == r.love;
}

struct UnionFind {
  vector<int> data;
  UnionFind(int size) : data(size, -1) {}
  bool unionSet(int x, int y) {
    x = root(x);
    y = root(y);
    if (x != y) {
      if (data[y] < data[x])
        swap(x, y);
      data[x] += data[y];
      data[y] = x;
    }
    return x != y;
  }
  bool findSet(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  int size(int x) { return -data[root(x)]; }
};
vector<Mod> dp(1e6 + 1);
Mod getrest(const int rest) {
  if (rest < 0) {
    return 0;
  } else {
    if (rest % 3) {
      assert(false);
      return 0;
    } else {
      return dp[rest / 3];
    }
  }
}
int N, M;
Mod getans(const map<int, int> &mp) {
  vector<int> v;

  Mod ans = 1;
  for (auto m : mp) {
    if (m.second >= 4)
      return 0;
    else if (m.second == 1) {
    } else {
      v.emplace_back(m.second);
    }
  }
  int rest = 3 * N - accumulate(v.begin(), v.end(), 0);
  if (N < v.size())
    return 0;
  for (auto n : v) {

    // if (rest < 3 - n) {
    //	//cout << 1 << endl;
    //	return 0;
    // }
    /*	if (n == 2) {
                    ans *= rest;
            }
            else {
                    assert(n == 3);
                    ans *= 1;
            }*/
    Mod a = n == 2 ? rest : 1;
    Mod b = comb(rest, 3 - n);
    while (a != b) {
      cout << 22 << endl;
    }
    ans *= comb(rest, 3 - n);

    rest -= (3 - n);
  }
  ans *= getrest(rest);
  return ans;
}
int main() {
  dp[0] = 1;
  for (int i = 1; i <= 100000; ++i) {
    dp[i] = dp[i - 1] * Mod(3 * i - 1) * Mod(3 * i - 2) / Mod(2);
  }
  init();
  cin >> N >> M;
  vector<rel> rels;
  vector<rel> hates;
  set<int> aset;
  for (int i = 0; i < M; ++i) {
    int a, b, c;
    cin >> a >> b >> c;
    c = !c;
    a--;
    b--;
    aset.emplace(a);
    aset.emplace(b);
    rels.push_back(rel{a, b, c});
    if (find(rels.begin(), rels.end(), rel{b, a, c}) != rels.end()) {
      // cout << "a" << endl;
      return 0;
    }
    if (find(rels.begin(), rels.end(), rel{b, a, !c}) != rels.end()) {
      // cout << "a" << endl;
      return 0;
    }
  }
  map<int, int> mp;
  int n = 0;
  for (auto s : aset) {
    mp[s] = n;
    n++;
  }
  for (auto &r : rels) {
    r.a = mp[r.a];
    r.b = mp[r.b];
  }
  UnionFind uf(aset.size());
  for (int i = 0; i < M; ++i) {
    if (rels[i].love) {
      uf.unionSet(rels[i].a, rels[i].b);
    } else {
      hates.emplace_back(rels[i]);
    }
  }
  assert(hates.size() <= 18);
  Mod ans = 0;
  for (int i = 0; i < (1 << hates.size()); ++i) {
    UnionFind nowuf(uf);
    bitset<18> bs(i);
    for (int j = 0; j < hates.size(); ++j) {

      if (bs[j]) {
        nowuf.unionSet(hates[j].a, hates[j].b);
      }
    }
    map<int, int> lovemp;
    for (int j = 0; j < aset.size(); ++j) {
      lovemp[nowuf.root(j)]++;
    }
    if (bs.count() % 2) {
      ans -= getans(lovemp);
    } else {
      ans += getans(lovemp);
    }
  }
  cout << ans << endl;
  return 0;
}