Problem p02728 (C++) — buggy submission, verdict: Runtime Error

/*
 * じょえチャンネル
 * 高評価・チャンネル登録よろしくおねがいします！
 * https://www.youtube.com/channel/UCRXsI3FL_kvaVL9zoolBfbQ
 */

#include <bits/stdc++.h>

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#define f(i, n) for (int i = 0; i < (n); i++)

#define inf (int)(3e18)

// here!!!
//  define int long long !!!!!

#define int long long

// define int long long !!!!!

#define mod (int)((1e9) + 7)

#define intt long long
#define itn long long
#define P pair<int, int>

#define rep(i, n) for (int i = 0; i < n; i++)
#define REP(i, n) for (int i = 1; i <= n; i++)

#define ALL(v) v.begin(), v.end()

using namespace std;

// Library
// モッドパウ
inline int modpow(int x, int y, int m = mod) {
  int res = 1;
  while (y) {
    if (y % 2) {
      res *= x;
      res %= m;
    }
    x = x * x % m;
    y /= 2;
  }
  return res;
}

int mypow(int x, int y) {
  int res = 1;
  while (y) {
    if (y % 2) {
      res *= x;
    }
    x = x * x;
    y /= 2;
  }
  return res;
}
// is the number (x) a prime number?
bool prime(int x) {
  for (int i = 2; i * i <= x; i++) {
    if (!(x % i)) {
      return false;
    }
  }
  return true;
}

// saidai-kouyakusuu
inline int gcd(int x, int y) {
  if (!y) {
    return x;
  }
  return gcd(y, x % y);
}

// number of keta
int keta(int x) {
  int ans = 0;
  while (x) {
    x /= 10;
    ans++;
  }
  return ans;
}

// sum of keta
int ketasum(int x) {
  int ans = 0;
  while (x) {
    ans += x % 10;
    x /= 10;
  }
  return ans;
}

inline int lcm(int x, int y) {
  int ans = x / gcd(x, y) * y;
  return ans;
}
int twobeki(int x) {
  int ans = 0;
  while (1) {
    if (!(x & 1)) {
      ans++;
      x /= 2;
    } else {
      break;
    }
  }
  return ans;
}

template <class T, class U> inline bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }

#define fin(i) scanf("%lld", &i)
#define fout(i) printf("%lld", i)
#define fendl printf("\\n")
// Library-End

class modInt {
  int value, modulo;

public:
  modInt() : value(0), modulo(mod) { value = 0; }
  template <typename T>
  modInt(T value = 0, int modulo = mod) : value(value), modulo(modulo) {
    if (value < 0) {
      value = -value;
      value %= modulo;
      value = -value;
      value += modulo;
    }
    this->value = value % modulo;
  }
  inline operator int() const { return value; }
  inline modInt &operator+=(modInt x) {
    value += x.value;
    if (value >= modulo)
      value -= modulo;
    return *this;
  }
  inline modInt &operator++() {
    if (value == modulo - 1)
      value = 0;
    else
      value++;
    return *this;
  }
  inline modInt &operator-() const { return modInt(0) -= *this; }
  inline modInt &operator-=(modInt x) {
    value -= x.value;
    if (value < 0)
      value += modulo;
    return *this;
  }
  inline modInt &operator--() {
    if (value == 0)
      value = modulo - 1;
    else
      value--;
    return *this;
  }
  inline modInt &operator*=(modInt x) {
    value = value * x.value % modulo;
    return *this;
  }
  inline modInt &operator/=(modInt x) { return operator*=(x.inv()); }
  inline modInt inv() { return modpow(*this, modulo - 2); }
  template <typename T> modInt operator+(T x) { return modInt(*this) += x; }
  template <typename T> modInt &operator+=(T x) {
    return operator+=(modInt(x, modulo));
  }
  template <typename T> modInt operator-(T x) { return modInt(*this) -= x; }
  template <typename T> modInt &operator-=(T x) {
    return operator-=(modInt(x, modulo));
  }
  template <typename T> modInt operator*(T x) { return modInt(*this) *= x; }
  template <typename T> modInt &operator*=(T x) {
    return operator*=(modInt(x, modulo));
  }
  template <typename T> modInt operator/(T x) { return modInt(*this) /= x; }
  template <typename T> modInt &operator/=(T x) {
    return operator/=(modInt(x, modulo));
  }
};
istream &operator>>(istream &ist, modInt &x) {
  int a;
  ist >> a;
  x = a;
  return ist;
}
#define vecin(v)                                                               \\
  for (int i = 0; i < v.size(); i++)                                           \\
    scanf("%lld", &v[i]);
#define vecout(v)                                                              \\
  {                                                                            \\
    printf("%lld", v[0]);                                                      \\
    for (int i = 1; i < v.size(); i++)                                         \\
      printf(" %lld", v[i]);                                                   \\
    printf("\\n");                                                              \\
  }

int perm[1000005];
void init_perm() {
  perm[0] = 1;
  REP(i, 1000000) { perm[i] = perm[i - 1] * i % mod; }
}

int nCk(int x, int y) {
  return perm[x] * modpow(perm[x - y], mod - 2) % mod *
         modpow(perm[y], mod - 2) % mod;
}

int n, a[200004], b[200004], dp[200004], dp2[200004], dp3[200004];
vector<int> road[200004];

inline int moddiv(int x, int y) { return x * modpow(y, mod - 2) % mod; }

void dfs1(int x, int par) {
  dp[x] = 1;
  for (int i : road[x]) {
    if (i == par) {
      continue;
    }
    dfs1(i, x);
    dp[x] += dp[i];
  }
}
void dfs2(int x, int par) {
  int waru = 1;
  int kake = 1;
  for (int i : road[x]) {
    if (i == par) {
      continue;
    }
    dfs2(i, x);
    dp2[x] += dp[i];
    waru *= perm[dp[i]];
    waru %= mod;
    kake *= dp2[i];
    kake %= mod;
  }
  dp2[x] = perm[dp2[x]];
  dp2[x] *= kake;
  dp2[x] %= mod;
  dp2[x] *= modpow(waru, mod - 2);
  dp2[x] %= mod;
}

void dfs3(int x, P dpar, int par) {
  int cnt = 0;
  int kake = 1;
  int waru = 1;

  rep(i, road[x].size()) {
    if (road[x][i] == par) {
      cnt += dpar.first;
      waru *= perm[dpar.first];
      waru %= mod;
      kake *= dpar.second;
      kake %= mod;
      continue;
    }
    cnt += dp[road[x][i]];
    waru *= perm[dp[road[x][i]]];
    waru %= mod;
    kake *= dp2[road[x][i]];
    kake %= mod;
  }

  for (int i : road[x]) {
    if (i == par) {
      continue;
    }
    int ncnt = cnt - dp[i];
    ncnt = perm[ncnt];
    int nkake = moddiv(kake, dp2[i]);
    int nwaru = moddiv(waru, perm[dp[i]]);
    dfs3(i, {cnt - dp[i] + 1, moddiv(ncnt * nkake % mod, nwaru)}, x);
  }

  dp3[x] = moddiv(perm[cnt] * kake % mod, waru);
}

signed main() {
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  cin >> n;
  init_perm();
  rep(i, n - 1) {
    cin >> a[i] >> b[i];
    road[a[i]].push_back(b[i]);
    road[b[i]].push_back(a[i]);
  }
  dfs1(1, 0);
  dfs2(1, 0);
  dfs3(1, {0, 1}, 0);
  REP(i, n) { cout << dp3[i] << endl; }
}


Error: 0

Fixed submission:

/*
 * じょえチャンネル
 * 高評価・チャンネル登録よろしくおねがいします！
 * https://www.youtube.com/channel/UCRXsI3FL_kvaVL9zoolBfbQ
 */

#include <bits/stdc++.h>

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#define f(i, n) for (int i = 0; i < (n); i++)

#define inf (int)(3e18)

// here!!!
//  define int long long !!!!!

#define int long long

// define int long long !!!!!

#define mod (int)(1000000007)

#define intt long long
#define itn long long
#define P pair<int, int>

#define rep(i, n) for (int i = 0; i < n; i++)
#define REP(i, n) for (int i = 1; i <= n; i++)

#define ALL(v) v.begin(), v.end()

using namespace std;

// Library
// モッドパウ
int modpow(int x, int y, int m = mod) {
  int res = 1;
  while (y) {
    if (y % 2) {
      res *= x;
      res %= m;
    }
    x = x * x % m;
    y /= 2;
  }
  return res;
}

int mypow(int x, int y) {
  int res = 1;
  while (y) {
    if (y % 2) {
      res *= x;
    }
    x = x * x;
    y /= 2;
  }
  return res;
}
// is the number (x) a prime number?
bool prime(int x) {
  for (int i = 2; i * i <= x; i++) {
    if (!(x % i)) {
      return false;
    }
  }
  return true;
}

// saidai-kouyakusuu
inline int gcd(int x, int y) {
  if (!y) {
    return x;
  }
  return gcd(y, x % y);
}

// number of keta
int keta(int x) {
  int ans = 0;
  while (x) {
    x /= 10;
    ans++;
  }
  return ans;
}

// sum of keta
int ketasum(int x) {
  int ans = 0;
  while (x) {
    ans += x % 10;
    x /= 10;
  }
  return ans;
}

inline int lcm(int x, int y) {
  int ans = x / gcd(x, y) * y;
  return ans;
}
int twobeki(int x) {
  int ans = 0;
  while (1) {
    if (!(x & 1)) {
      ans++;
      x /= 2;
    } else {
      break;
    }
  }
  return ans;
}

template <class T, class U> inline bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }

#define fin(i) scanf("%lld", &i)
#define fout(i) printf("%lld", i)
#define fendl printf("\\n")
// Library-End

class modInt {
  int value, modulo;

public:
  modInt() : value(0), modulo(mod) { value = 0; }
  template <typename T>
  modInt(T value = 0, int modulo = mod) : value(value), modulo(modulo) {
    if (value < 0) {
      value = -value;
      value %= modulo;
      value = -value;
      value += modulo;
    }
    this->value = value % modulo;
  }
  inline operator int() const { return value; }
  inline modInt &operator+=(modInt x) {
    value += x.value;
    if (value >= modulo)
      value -= modulo;
    return *this;
  }
  inline modInt &operator++() {
    if (value == modulo - 1)
      value = 0;
    else
      value++;
    return *this;
  }
  inline modInt &operator-() const { return modInt(0) -= *this; }
  inline modInt &operator-=(modInt x) {
    value -= x.value;
    if (value < 0)
      value += modulo;
    return *this;
  }
  inline modInt &operator--() {
    if (value == 0)
      value = modulo - 1;
    else
      value--;
    return *this;
  }
  inline modInt &operator*=(modInt x) {
    value = value * x.value % modulo;
    return *this;
  }
  inline modInt &operator/=(modInt x) { return operator*=(x.inv()); }
  inline modInt inv() { return modpow(*this, modulo - 2); }
  template <typename T> modInt operator+(T x) { return modInt(*this) += x; }
  template <typename T> modInt &operator+=(T x) {
    return operator+=(modInt(x, modulo));
  }
  template <typename T> modInt operator-(T x) { return modInt(*this) -= x; }
  template <typename T> modInt &operator-=(T x) {
    return operator-=(modInt(x, modulo));
  }
  template <typename T> modInt operator*(T x) { return modInt(*this) *= x; }
  template <typename T> modInt &operator*=(T x) {
    return operator*=(modInt(x, modulo));
  }
  template <typename T> modInt operator/(T x) { return modInt(*this) /= x; }
  template <typename T> modInt &operator/=(T x) {
    return operator/=(modInt(x, modulo));
  }
};
istream &operator>>(istream &ist, modInt &x) {
  int a;
  ist >> a;
  x = a;
  return ist;
}
#define vecin(v)                                                               \\
  for (int i = 0; i < v.size(); i++)                                           \\
    scanf("%lld", &v[i]);
#define vecout(v)                                                              \\
  {                                                                            \\
    printf("%lld", v[0]);                                                      \\
    for (int i = 1; i < v.size(); i++)                                         \\
      printf(" %lld", v[i]);                                                   \\
    printf("\\n");                                                              \\
  }

int perm[1000005];
void init_perm() {
  perm[0] = 1;
  REP(i, 1000000) { perm[i] = perm[i - 1] * i % mod; }
}

int nCk(int x, int y) {
  return perm[x] * modpow(perm[x - y], mod - 2) % mod *
         modpow(perm[y], mod - 2) % mod;
}

int n, a[100004], b[100004], dp[100004], dp2[100004], dp3[100004];
vector<int> road[100004];

void dfs1(int x, int par) {
  dp[x] = 1;
  for (int i : road[x]) {
    if (i == par) {
      continue;
    }
    dfs1(i, x);
    dp[x] += dp[i];
  }
}
void dfs2(int x, int par) {
  int waru = 1;
  int kake = 1;
  for (int i : road[x]) {
    if (i == par) {
      continue;
    }
    dfs2(i, x);
    dp2[x] += dp[i];
    waru *= perm[dp[i]];
    waru %= mod;
    kake *= dp2[i];
    kake %= mod;
  }
  dp2[x] = perm[dp2[x]];
  dp2[x] *= kake;
  dp2[x] %= mod;
  dp2[x] *= modpow(waru, mod - 2);
  dp2[x] %= mod;
}

void dfs3(int x, P dpar, int par) {
  //    cout<<x<<' '<<par<<endl;
  vector<pair<P, int>> rui(road[x].size() + 10), rui2(road[x].size() + 10);
  rui[0].first.first = 1;
  rui[0].second = 1;
  rui2[road[x].size()].first.first = 1;
  rui2[road[x].size()].second = 1;
  rep(i, road[x].size()) {
    if (road[x][i] != par) {
      rui[i + 1].first.first = rui[i].first.first * perm[dp[road[x][i]]] % mod;
      rui[i + 1].first.second = rui[i].first.second + dp[road[x][i]];
      rui[i + 1].second = rui[i].second * dp2[road[x][i]] % mod;
    } else {
      rui[i + 1].first.first =
          rui[i].first.first * max(1ll, perm[dpar.first]) % mod;
      rui[i + 1].first.second = dpar.first + rui[i].first.second;
      rui[i + 1].second = rui[i].second * dpar.second % mod;
    }
  }
  for (int i = (int)road[x].size() - 1; i >= 0; i--) {
    if (road[x][i] != par) {
      rui2[i].first.first =
          rui2[i + 1].first.first * perm[dp[road[x][i]]] % mod;
      rui2[i].first.second = rui2[i + 1].first.second + dp[road[x][i]];
      rui2[i].second = rui2[i + 1].second * dp2[road[x][i]] % mod;
    } else {
      rui2[i].first.first =
          rui2[i + 1].first.first * max(1ll, perm[dpar.first]) % mod;
      rui2[i].first.second = dpar.first + rui2[i].first.second;
      rui2[i].second = rui2[i + 1].second * dpar.second % mod;
    }
  }
  for (int i = 0; i < road[x].size(); i++) {
    if (road[x][i] != par) {
      dfs3(road[x][i],
           {rui[i].first.second + rui2[i + 1].first.second + 1,
            perm[rui[i].first.second + rui2[i + 1].first.second] *
                modpow(rui[i].first.first * rui2[i + 1].first.first % mod,
                       mod - 2) %
                mod * rui[i].second % mod * rui2[i + 1].second % mod},
           x);
    }
  }
  dp3[x] = perm[rui[road[x].size()].first.second] *
           modpow(rui[road[x].size()].first.first, mod - 2) % mod *
           rui[road[x].size()].second % mod;
}

signed main() {
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  cin >> n;
  init_perm();
  rep(i, n - 1) {
    cin >> a[i] >> b[i];
    road[a[i]].push_back(b[i]);
    road[b[i]].push_back(a[i]);
  }
  dfs1(1, 0);
  dfs2(1, 0);
  dfs3(1, {0, 1}, 0);
  REP(i, n) { cout << dp3[i] << endl; }
}