Problem p02279 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <random>
#include <vector>
using namespace std;

#define REP(i, n) for (int(i) = 0; (i) < (n); (i)++)
#define For(i, a, b) for (int(i) = (a); (i) < (b); (i)++)
#define ALL(v) v.begin(), v.end()

const int NOT_DEFINED = -111;

class Tree {
  int n;
  vector<vector<int>> adjlist;
  vector<vector<int>> inv_adjlist;
  vector<int> depthList;

public:
  Tree(int num);
  int getParent(int id);
  void addNode(int parentId, int childId);
  int getDepth(int id);
  string getType(int id);
  vector<int> getChild(int id);
};

Tree::Tree(int num) {
  n = num;
  REP(i, num) {
    vector<int> v;
    adjlist.push_back(v);
    inv_adjlist.push_back(v);
    depthList.push_back(NOT_DEFINED);
  }
}

void Tree::addNode(int parentId, int childId) {
  adjlist[parentId].push_back(childId);
  inv_adjlist[childId].push_back(parentId);
}

int Tree::getParent(int id) {
  REP(i, n) {
    if (find(ALL(adjlist[i]), id) != adjlist[i].end()) {
      return i;
    }
  }
  return -1;
}

int Tree::getDepth(int id) {
  // if (depthList[id] != NOT_DEFINED) return depthList[id];
  int depth = 0;
  vector<int> parent = inv_adjlist[id];
  while (parent.size()) {
    if (depthList[parent[0]] != NOT_DEFINED) {
      depth += depthList[parent[0]] + 1;
      break;
    }
    parent = inv_adjlist[parent[0]];
    depth++;
  }

  /* slow code
  int parent = id;
  while (1) {
      parent = getParent(parent);
      if (parent != -1) {
          depth++;
      }else {
          break;
      }
  }*/
  depthList[id] = depth;
  return depth;
}

string Tree::getType(int id) {
  if (depthList[id] == 0) {
    return "root";
  } else if (adjlist[id].empty()) {
    return "leaf";
  } else {
    return "internal node";
  }
  return "";
}

vector<int> Tree::getChild(int id) { return adjlist[id]; }

int main() {
  int n;
  cin >> n;
  Tree tree = Tree(n);
  REP(i, n) {
    int id, deg;
    cin >> id >> deg;
    int k;
    REP(j, deg) {
      cin >> k;
      tree.addNode(id, k);
    }
  }

  REP(i, n) {
    vector<int> children = tree.getChild(i);
    cout << "node " << i << ": parent = ";
    cout << tree.getParent(i) << ", depth = ";
    cout << tree.getDepth(i) << ", ";
    cout << tree.getType(i) << ", [";
    REP(j, children.size()) {
      cout << children[j];
      if (j < children.size() - 1) {
        cout << ", ";
      }
    }
    cout << "]" << endl;
  }
  return 0;
}

Fixed submission:
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <random>
#include <vector>
using namespace std;

#define REP(i, n) for (int(i) = 0; (i) < (n); (i)++)
#define For(i, a, b) for (int(i) = (a); (i) < (b); (i)++)
#define ALL(v) v.begin(), v.end()

const int NOT_DEFINED = -111;

class Tree {
  int n;
  vector<vector<int>> adjlist;
  vector<vector<int>> inv_adjlist;
  vector<int> depthList;

public:
  Tree(int num);
  int getParent(int id);
  void addNode(int parentId, int childId);
  int getDepth(int id);
  string getType(int id);
  vector<int> getChild(int id);
};

Tree::Tree(int num) {
  n = num;
  REP(i, num) {
    vector<int> v;
    adjlist.push_back(v);
    inv_adjlist.push_back(v);
    depthList.push_back(NOT_DEFINED);
  }
}

void Tree::addNode(int parentId, int childId) {
  adjlist[parentId].push_back(childId);
  inv_adjlist[childId].push_back(parentId);
}

int Tree::getParent(int id) {
  vector<int> parent = inv_adjlist[id];
  if (parent.size())
    return parent[0];
  return -1;
}

int Tree::getDepth(int id) {
  // if (depthList[id] != NOT_DEFINED) return depthList[id];
  int depth = 0;
  vector<int> parent = inv_adjlist[id];
  while (parent.size()) {
    if (depthList[parent[0]] != NOT_DEFINED) {
      depth += depthList[parent[0]] + 1;
      break;
    }
    parent = inv_adjlist[parent[0]];
    depth++;
  }

  /* slow code
  int parent = id;
  while (1) {
      parent = getParent(parent);
      if (parent != -1) {
          depth++;
      }else {
          break;
      }
  }*/
  depthList[id] = depth;
  return depth;
}

string Tree::getType(int id) {
  if (depthList[id] == 0) {
    return "root";
  } else if (adjlist[id].empty()) {
    return "leaf";
  } else {
    return "internal node";
  }
  return "";
}

vector<int> Tree::getChild(int id) { return adjlist[id]; }

int main() {
  int n;
  cin >> n;
  Tree tree = Tree(n);
  REP(i, n) {
    int id, deg;
    cin >> id >> deg;
    int k;
    REP(j, deg) {
      cin >> k;
      tree.addNode(id, k);
    }
  }

  REP(i, n) {
    vector<int> children = tree.getChild(i);
    cout << "node " << i << ": parent = ";
    cout << tree.getParent(i) << ", depth = ";
    cout << tree.getDepth(i) << ", ";
    cout << tree.getType(i) << ", [";
    REP(j, children.size()) {
      cout << children[j];
      if (j < children.size() - 1) {
        cout << ", ";
      }
    }
    cout << "]" << endl;
  }
  return 0;
}