Problem p02728 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

// #define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int> P;
#define stop                                                                   \
  char nyaa;                                                                   \
  cin >> nyaa;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
#define all(v) (v).begin(), (v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);

ll mod_pow(ll a, ll n, ll m = mod) {
  ll res = 1;
  while (n) {
    if (n & 1)
      res = res * a % m;
    a = a * a % m;
    n >>= 1;
  }
  return res;
}

struct modint {
  ll n;
  modint() : n(0) { ; }
  modint(ll m) : n(m) {
    if (n >= mod)
      n %= mod;
    else if (n < 0)
      n = (n % mod + mod) % mod;
  }
  operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) {
  a.n += b.n;
  if (a.n >= mod)
    a.n -= mod;
  return a;
}
modint operator-=(modint &a, modint b) {
  a.n -= b.n;
  if (a.n < 0)
    a.n += mod;
  return a;
}
modint operator*=(modint &a, modint b) {
  a.n = ((ll)a.n * b.n) % mod;
  return a;
}
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
  if (n == 0)
    return modint(1);
  modint res = (a * a) ^ (n / 2);
  if (n % 2)
    res = res * a;
  return res;
}

ll inv(ll a, ll p) { return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p); }
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }
const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
  fact[0] = modint(1);
  for (int i = 0; i < max_n - 1; i++) {
    fact[i + 1] = fact[i] * modint(i + 1);
  }
  factinv[max_n - 1] = modint(1) / fact[max_n - 1];
  for (int i = max_n - 2; i >= 0; i--) {
    factinv[i] = factinv[i + 1] * modint(i + 1);
  }
}
modint comb(int a, int b) {
  if (a < 0 || b < 0 || a < b)
    return 0;
  return fact[a] * factinv[b] * factinv[a - b];
}

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

using Data = pair<int, modint>;
Data merge(Data a, Data b) {
  Data res;
  //
  res.first = a.first + b.first;
  res.second = a.second * b.second * comb(a.first + b.first, a.first);
  //
  return res;
}
const int mn = 1 << 18;
struct edge {
  int to;
};
vector<edge> G[mn];
vector<int> ids[mn];
vector<Data> memo[mn];
int root;

Data dfs(int id, int fr) {
  Data res;
  //
  // initialize
  res.first = 0, res.second = 1;
  //
  for (edge e : G[id]) {
    if (e.to == fr)
      continue;
    Data nex = dfs(e.to, id);
    //
    // update with edge
    //
    res = merge(res, nex);
    ids[id].push_back(e.to);
    memo[id].push_back(nex);
  }
  //
  // update for return
  res.first++;
  //
  return res;
}
modint ans[1 << 17];
void invdfs(int id, int fr, Data pre) {
  vector<Data> v;
  for (Data d : memo[id])
    v.push_back(d);
  if (fr >= 0)
    v.push_back(pre);
  int len = v.size();
  //
  // calcurate id's ans
  Data tans = {0, 1};
  rep(i, v.size()) { tans = merge(tans, v[i]); }
  ans[id] = tans.second;
  //
  vector<Data> le(len + 1);
  vector<Data> ri(len + 1);
  //
  Data init_c = {0, 1};
  //
  le[0] = init_c;
  rep(i, len) { le[i + 1] = merge(le[i], v[i]); }
  ri[len] = init_c;
  per(i, len) { ri[i] = merge(ri[i + 1], v[i]); }
  rep(i, ids[id].size()) {
    int to = ids[id][i];
    Data d = merge(le[i], ri[i + 1]);

    //
    // update for return
    d.first++;
    //
    invdfs(to, id, d);
  }
}
void yaru() {
  dfs(root, -1);
  invdfs(root, -1, {0, 1});
}

void solve() {
  int n;
  cin >> n;
  rep(i, n - 1) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    G[a].push_back({b});
    G[b].push_back({a});
  }
  yaru();
  rep(i, n) { cout << ans[i] << "\n"; }
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(7);
  init_f();
  // init();
  // int t; cin >> t; rep(i, t)solve();
  solve();
  stop return 0;
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

// #define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int> P;
#define stop                                                                   \
  char nyaa;                                                                   \
  cin >> nyaa;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
#define all(v) (v).begin(), (v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);

ll mod_pow(ll a, ll n, ll m = mod) {
  ll res = 1;
  while (n) {
    if (n & 1)
      res = res * a % m;
    a = a * a % m;
    n >>= 1;
  }
  return res;
}

struct modint {
  ll n;
  modint() : n(0) { ; }
  modint(ll m) : n(m) {
    if (n >= mod)
      n %= mod;
    else if (n < 0)
      n = (n % mod + mod) % mod;
  }
  operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) {
  a.n += b.n;
  if (a.n >= mod)
    a.n -= mod;
  return a;
}
modint operator-=(modint &a, modint b) {
  a.n -= b.n;
  if (a.n < 0)
    a.n += mod;
  return a;
}
modint operator*=(modint &a, modint b) {
  a.n = ((ll)a.n * b.n) % mod;
  return a;
}
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
  if (n == 0)
    return modint(1);
  modint res = (a * a) ^ (n / 2);
  if (n % 2)
    res = res * a;
  return res;
}

ll inv(ll a, ll p) { return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p); }
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }
const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
  fact[0] = modint(1);
  for (int i = 0; i < max_n - 1; i++) {
    fact[i + 1] = fact[i] * modint(i + 1);
  }
  factinv[max_n - 1] = modint(1) / fact[max_n - 1];
  for (int i = max_n - 2; i >= 0; i--) {
    factinv[i] = factinv[i + 1] * modint(i + 1);
  }
}
modint comb(int a, int b) {
  if (a < 0 || b < 0 || a < b)
    return 0;
  return fact[a] * factinv[b] * factinv[a - b];
}

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

using Data = pair<int, modint>;
Data merge(Data a, Data b) {
  Data res;
  //
  res.first = a.first + b.first;
  res.second = a.second * b.second * comb(a.first + b.first, a.first);
  //
  return res;
}
const int mn = 1 << 18;
struct edge {
  int to;
};
vector<edge> G[mn];
vector<int> ids[mn];
vector<Data> memo[mn];
int root;

Data dfs(int id, int fr) {
  Data res;
  //
  // initialize
  res.first = 0, res.second = 1;
  //
  for (edge e : G[id]) {
    if (e.to == fr)
      continue;
    Data nex = dfs(e.to, id);
    //
    // update with edge
    //
    res = merge(res, nex);
    ids[id].push_back(e.to);
    memo[id].push_back(nex);
  }
  //
  // update for return
  res.first++;
  //
  return res;
}
modint ans[1 << 18];
void invdfs(int id, int fr, Data pre) {
  vector<Data> v;
  for (Data d : memo[id])
    v.push_back(d);
  if (fr >= 0)
    v.push_back(pre);
  int len = v.size();
  //
  // calcurate id's ans
  Data tans = {0, 1};
  rep(i, v.size()) { tans = merge(tans, v[i]); }
  ans[id] = tans.second;
  //
  vector<Data> le(len + 1);
  vector<Data> ri(len + 1);
  //
  Data init_c = {0, 1};
  //
  le[0] = init_c;
  rep(i, len) { le[i + 1] = merge(le[i], v[i]); }
  ri[len] = init_c;
  per(i, len) { ri[i] = merge(ri[i + 1], v[i]); }
  rep(i, ids[id].size()) {
    int to = ids[id][i];
    Data d = merge(le[i], ri[i + 1]);

    //
    // update for return
    d.first++;
    //
    invdfs(to, id, d);
  }
}
void yaru() {
  dfs(root, -1);
  invdfs(root, -1, {0, 1});
}

void solve() {
  int n;
  cin >> n;
  rep(i, n - 1) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    G[a].push_back({b});
    G[b].push_back({a});
  }
  yaru();
  rep(i, n) { cout << ans[i] << "\n"; }
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(7);
  init_f();
  // init();
  // int t; cin >> t; rep(i, t)solve();
  solve();
  stop return 0;
}