Go: #include <bits/stdc++.h>
using namespace std;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int N     = 100;

int n, tt;
vector<vector<int>> M(N, vector<int>(N));
vector<int> color(N), d(N), f(N);

void dfs_visit(int u) {
  color[u] = GRAY;
  d[u]     = ++tt;
  for (int v = 0; v < n; v++) {
    if (M[u][v] == 0) continue;
    if (color[v] == WHITE) { dfs_visit(v); }
  }
  color[u] = BLACK;
  f[u]     = ++tt;
}

void dfs() {
  tt = 0;

  for (int u = 0; u < n; u++) {
    if (color[u] == WHITE) dfs_visit(u);
  }
  for (int u = 0; u < n; u++) {
    printf("%d %d %d\n", u + 1, d[u], f[u]);
  }
}

int main() {
  int u, v, k;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    u--;
    for (int j = 0; j < k; j++) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <climits>
#include <cstring>


using namespace std;

const int N_MAX = 1000000;
/*
bool update_num_to_visit(int st, int en, int* arr){
  if(st==-1) return false;
  arr[st]--;
  return arr[st]==0;
  }*/

int main(){
  int n;
  cin >> n;
  stack<pair<int, int> > edges;
  stack<pair<int, int> > paths;
  
  int** adjl = new int*[n];
  int* d = new int[n];
  int* f = new int[n];
  
  for(int i=0; i<n; i++){
    adjl[i] = new int[n];
    memset(adjl[i], -1, n * sizeof(adjl[i][0]));
  }
  
  memset(d, -1, n*sizeof(d[0]));
  memset(f, -1, n*sizeof(f[0]));

  for(int i=0; i<n; i++){
    int row_num, k;
    cin >> row_num >> k; row_num--;
    
    for(int j=0; j<k; j++){
      int node_num;
      cin >> node_num; node_num--;
      adjl[row_num][j] = node_num; // [[3, 5, -1 , ...], [1, 3, -1, ...], [1, 2], ...]
    }
  }

  for(int row_num=n-1; row_num>=0; row_num--){
      pair<int, int> p;
      p.first = -1; p.second = row_num; // visited from nowhere
      edges.push(p);
    }

  int time = 1;
  while(!edges.empty()){
    //    cout << "time: " << time << endl;
    
    pair<int, int> edge;
    edge = edges.top(); edges.pop();
    int st, en; st = edge.first; en = edge.second;
    //    cout << "visiting: " << en << " from: " << st << endl;
    
    pair<int, int> path; 
    // record path to go back
    if(st > -1){ // exclude (-1, node)
      path.first = en; path.second = st;
      // avoid inf loop: if the node is not finished, have to go back at some point
      if(f[path.second] == -1){
	paths.push(path);
	// cout << "<" << path.first << ", " << path.second << "> pushed as a path." << endl;
      }
    }    
    
    // if first time visit, mark as visited
    if(d[en] == -1) d[en] = time;
    
    // if not first time, check if it was finished.
    // if it was already finished, continue
    if(f[en] != -1){
      continue;
    }
    
    // counter for opened nodes
    int unvisited_node_num = 0;

    // open node (reverse order)
    for(int i=n-1; i>=0; i--){
      int next_node = adjl[en][i];
      // cout << "next_node: " << next_node << endl;
      // undefined dest or visited, continue
      if(next_node == -1) continue;
      if(d[next_node] != -1){
	// if num_to_visit[en] > 0;
	continue;
      }
      // if unvisited, push into stack
      unvisited_node_num++;
      pair<int, int> next_edge; next_edge.first = en; next_edge.second = next_node;
      edges.push(next_edge);
      // cout << "<" << next_edge.first << ", " << next_edge.second << "> pushed." << endl;
    }

    // if there are no unvisited linked nodes anymore, mark the node finished
    if(unvisited_node_num == 0){
      // cout << "going back..." << endl;
      f[en] = time + 1;
      // cout << "f[" << en << "]: " << f[en] << endl;
      
      // way to go back
      if(paths.empty()) break;
      path = paths.top(); paths.pop();
      edges.push(path);
      // cout << "path pushed." << endl;
    }
    time++;
  }

  // print 'i+1, d[i], f[i]'
  
  for(int i=0; i<n; i++){
    cout << i+1 << " " << d[i] << " " << f[i] << endl;
  }
  
  for(int i=0; i<n; i++){
    delete[] adjl[i];
  }
  delete[] adjl;
  delete[] d;
  delete[] f;
  
  return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B

#include <iostream>
#include <iomanip>

#include <vector>
#include <string>
#include <iterator>
#include <algorithm>

typedef long long ll;
const long double PI = (acos(-1));
const long long MOD = 1000000007;
#define rep(i,n) REP(i,0,n)
#define REP(i,x,n) for(int i=x;i<n;++i)

using namespace std;

// change min/max
template<class T> inline bool chMin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chMax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

template<class T> void output(std::vector<T> & A) {
    const int n = A.size();
    for (int i = 0; i < n - 1; ++i) {
        std::cout << A[i] << " ";
    }
    std::cout << A[n - 1] << std::endl;
}

const int WHITE = 0;
const int GRAY  = 1;
const int BLACK = 2;
vector<vector<int>> M;
vector<int> colour, d, f;
int tt = 0;

void dfs(int u) {
    // if black exit
    if (colour[u] == BLACK) return;
    
    // if white
    if (colour[u] == WHITE) {
        colour[u] = GRAY;
        d[u] = tt++;
        const int nb = M[u].size();
        rep(i, nb) {
            dfs(M[u][i]);
        }
        // if you are here, all the neigbours are already checked
        f[u] = tt++;
        colour[u] = BLACK;
    }
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    std::cout << std::fixed << std::setprecision(15);

    // populate M
    int n; cin >> n;
    M = vector<vector<int>>(n);
    colour = vector<int>(n, 0);
    d = vector<int>(n, -1);
    f = vector<int>(n, -1);

    rep(i, n) {
        int from; cin >> from; --from;
        int m; cin >> m;
        rep(j, m) {
            int to; cin >> to; --to;
            M[from].push_back(to);
            // M[to].push_back(from);
        }
    }

    // dfs
    rep(i, n) {
        if (colour[i] == WHITE) {
            dfs(i);
        }
    }

    rep(i, n) {
        cout << (i + 1) << " " << (d[i] + 1) << " " << (f[i] + 1) << endl;
    }

    return 0;
}