Problem p03044 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

using ll = long long;

#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define ddrep(i, n) for (int i = n; i > 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define ssrep(i, s, t) for (int i = s; i <= t; ++i)

#define rng(a) a.begin(), a.end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

#define chmax(x, y) (x = max(x, y))
#define chmin(x, y) (x = min(x, y))

using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using ld = long double;

template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, (int)v.size()) {
    if (i)
      os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}

template <typename T, size_t S> void printArray(const T (&array)[S]) {
  for (auto val : array)
    std::cout << val << ", ";
  std::cout << "\n";
}

const int mod = 1e9 + 7;
const ll inf = 1e18 + 5;

struct UnionFind {
  vi parent, rank, count;
  UnionFind(const int nodeSize)
      : parent(nodeSize), rank(nodeSize, 1), count(nodeSize) {
    rep(i, nodeSize) parent[i] = i, count[i] = 1;
  }
  int find(int x) {
    if (parent[x] == x)
      return x;
    return parent[x] = find(parent[x]);
  }
  void unite(int x, int y) {
    int rx = find(x);
    int ry = find(y);
    if (rx == ry)
      return;
    if (rank[rx] < rank[ry])
      swap(rx, ry);
    parent[ry] = rx;
    count[rx] += count[ry];
    if (rank[rx] == rank[ry])
      ++rank[rx];
  }
  bool same(int x, int y) { return find(x) == find(y); }
  int num(int x) { return count[find(x)]; }
};

struct Edge {
  int to, cost;
};
vector<vector<Edge>> tree;
vl ans;
void dfs(int par, int now) {
  for (auto &edge : tree[now])
    if (edge.to != par) {
      ans[edge.to] = ans[now] + edge.cost;
      dfs(now, edge.to);
    }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << std::setprecision(10);

  int n;
  std::cin >> n;
  tree.resize(n);
  rep(i, n) {
    int u, v, w;
    std::cin >> u >> v >> w;
    u--, v--;
    tree[u].pb({v, w}), tree[v].pb({u, w});
  }
  ans.resize(n);
  ans[0] = 0;
  dfs(-1, 0);
  rep(i, n) std::cout << (ans[i] & 1) << "\n";
}


Fixed submission:
#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

using ll = long long;

#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define ddrep(i, n) for (int i = n; i > 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define ssrep(i, s, t) for (int i = s; i <= t; ++i)

#define rng(a) a.begin(), a.end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

#define chmax(x, y) (x = max(x, y))
#define chmin(x, y) (x = min(x, y))

using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using ld = long double;

template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, (int)v.size()) {
    if (i)
      os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}

template <typename T, size_t S> void printArray(const T (&array)[S]) {
  for (auto val : array)
    std::cout << val << ", ";
  std::cout << "\n";
}

const int mod = 1e9 + 7;
const ll inf = 1e18 + 5;

struct UnionFind {
  vi parent, rank, count;
  UnionFind(const int nodeSize)
      : parent(nodeSize), rank(nodeSize, 1), count(nodeSize) {
    rep(i, nodeSize) parent[i] = i, count[i] = 1;
  }
  int find(int x) {
    if (parent[x] == x)
      return x;
    return parent[x] = find(parent[x]);
  }
  void unite(int x, int y) {
    int rx = find(x);
    int ry = find(y);
    if (rx == ry)
      return;
    if (rank[rx] < rank[ry])
      swap(rx, ry);
    parent[ry] = rx;
    count[rx] += count[ry];
    if (rank[rx] == rank[ry])
      ++rank[rx];
  }
  bool same(int x, int y) { return find(x) == find(y); }
  int num(int x) { return count[find(x)]; }
};

struct Edge {
  int to, cost;
};
vector<vector<Edge>> tree;
vl ans;
void dfs(int par, int now) {
  for (auto &edge : tree[now])
    if (edge.to != par) {
      ans[edge.to] = ans[now] + edge.cost;
      dfs(now, edge.to);
    }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << std::setprecision(10);

  int n;
  std::cin >> n;
  tree.resize(n);
  rep(i, n - 1) {
    int u, v, w;
    std::cin >> u >> v >> w;
    u--, v--;
    tree[u].pb({v, w}), tree[v].pb({u, w});
  }
  ans.resize(n);
  ans[0] = 0;
  dfs(-1, 0);
  rep(i, n) std::cout << (ans[i] & 1) << "\n";
}