Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), 0, 0}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}

	s := Stack{}
	for i := 1; i < len(nodes)+1; i++ {
		if nodes[i].s != 0 {
			continue
		}
		walk(i, &nodes, s)
	}
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v %v\n", (*nodes[i]).id, (*nodes[i]).s, (*nodes[i]).e)
	}
}

var time int

func walk(nid int, nodes *map[int]*node, s Stack) {
	n := (*nodes)[nid]
	if n.s != 0 {
		return
	}
	time++
	n.s = time
	s.Push(n)
	for _, v := range n.nexts {
		walk(v, nodes, s)
	}
	time++
	n.e = time
}

type node struct {
	id    int
	nexts []int
	s     int
	e     int
}

// Stack is Stack
type Stack struct {
	stack []interface{}
}

// Push new value
func (stack *Stack) Push(val interface{}) {
	stack.stack = append(stack.stack, val)
}

// Pop new value
func (stack *Stack) Pop() interface{} {
	val := stack.stack[len(stack.stack)-1]
	stack.stack = stack.stack[0 : len(stack.stack)-1]
	return val
}

C++: #include <iostream>
#include <vector>
#include <stack>
#include <algorithm>

using namespace std;

enum COLOR {
  WHITE,
  GRAY,
  BLACK,
};

static const int NIL = -1;
static const int N = 100;

static int M[N][N] = {};

static inline int next(int u, int n, int next_array[]) {
  for (int v = next_array[u]; v < n; v++) {
    next_array[u] = v + 1;
    if (M[u][v]) {
      return v;
    }
  }
  return NIL;
}

static vector<int> u(N, 0);
static vector<COLOR> color(N, WHITE);
static int total_time = 0;
static vector<int> visit_time(N, 0), finish_time(N, 0);

static void dfs_visit(int r, int n) {
  vector<int> next_array(N, 0);

  stack<int> S;
  S.push(r);
  color[r] = GRAY;
  visit_time[r] = ++total_time;

  while (!S.empty()) {
    int u = S.top();
    int v = next(u, n, &next_array[0]);
    if (v != NIL) {
      if (color[v] == WHITE) {
        color[v] = GRAY;
        visit_time[v] = ++total_time;
        S.push(v);
      }
    } else {
      S.pop();
      color[u] = BLACK;
      finish_time[u] = ++total_time;
    }
  }
}

void dfs(int n) {
  for (int u = 0; u < n; u++) {
    if (color[u] == WHITE) {
      dfs_visit(u, n);
    }
  }
  
  for (int i = 0; i < n; i++) {
    cout << i + 1 << " " << visit_time[i] << " " << finish_time[i] << endl;
  }
}

int main() {
  int n;
  cin >> n;

  int number, count, value;
  for (int i = 0; i < n; i++) {
    cin >> number >> count;
    number--;
    for (int j = 0; j < count; j++) {
     cin >> value;
     value--;
     M[number][value] = 1; 
    }
  }
  
  dfs(n);

  return 0;
}

C++: /*
 * ALDS1_11_B.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<iostream>
#include<vector>

using namespace std;

int d[101];
int f[101];
int time;

void dfsRec(vector<int>* a, int n, int v) {
	if(d[v] > 0) return;
	time++;
	d[v] = time;
	for(int &x:a[v]) {
		dfsRec(a, n, x);
	}
	time++;
	f[v] = time;
}

int main() {
	int n;
	vector<int> adj[101];

	cin >> n;
	for(int i=0; i<n; i++) {
		int v;
		int k;
		cin >> v >> k;
		for(int j=0; j<k; j++) {
			int u;
			cin >> u;
			adj[v].push_back(u);
		}
	}

	dfsRec(adj, n, 1);

	for(int i=1; i<=n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105

int n, G[MAX][MAX], d[MAX], f[MAX], Mytime, st[MAX];

void dfs(int r) {
	if (st[r] != 0) return;
	int nt[n + 1], i;
	for (i = 1; i <= n; i++) {
		nt[i] = 1;
	}
	stack<int> S;
	S.push(r);
	d[r] = ++Mytime;
	st[r] = 1;
	while (!S.empty()) {
		int u = S.top();
		int v;
		for (v = nt[u]; v <= n; v++) {
			nt[u] = v + 1;
			if (G[u][v] && st[v] == 0) 
				break;
		}
		if (v <= n) {
			d[v] = ++Mytime;
			st[v] = 1;
			S.push(v);
		} else {
			S.pop();
			f[u] = ++Mytime;
		}
	}
}

int main(void) {
	int i, j, u, k, v;
	for (i = 0; i < MAX; i++) {
		d[i] = 0;
		f[i] = 0;
		st[i] = 0;
		for (j = 0; j < MAX; j++) {
			G[i][j] = 0;
		}
	}
	Mytime = 0;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u >> k;
		for (j = 0; j < k; j++) {
			cin >> v;
			G[u][v] = 1;
		}
	}
	for (i = 1; i <= n; i++) {
		dfs(i);
	}
	dfs(1);
	for (i = 1; i <= n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}
}

C++: #include <iostream>
#include <vector>
#include <numeric>

const int MAXINT = 10000;

// typedef std::vector<std::vector<int> > mat_int;
// typedef std::vector<std::vector<bool> > mat_bool;

void dfs(std::vector<std::vector<int> >& adj_list, std::vector<int>& d, std::vector<int>& f, int& time, int root = 0 ){
  if(d[root] > time){
    d[root] = time;
    for(int const& v: adj_list[root]){
      time++;
      dfs(adj_list, d, f, time, v);
    }
    time++;
    f[root] = time;
  }

}


int main(int argc, char const *argv[]) {
  int n; // .. 100
  std::cin >> n;
  // mat_bool adj(n, std::vector<bool>(n));
  // mat_int d(n, std::vector<int>(n)), f(n, std::vector<int>(n));
  std::vector<std::vector<int> > adj_list(n);
  std::vector<int> d(n, MAXINT), f(n, MAXINT);

  for(int q=0; q<n; ++q){
    int i_plus_1, k;
    std::cin >> i_plus_1;
    std::cin >> k;
    for(int p=0; p<k; ++p){
      int j_plus_1;
      std::cin >> j_plus_1;
      // adj[i_plus_1-1][j_plus_1-1] = true;
      adj_list[i_plus_1 - 1].push_back(j_plus_1-1);
    }
  }

  int t = 1;
  dfs(adj_list, d, f, t);

  for(int i=0; i<n; ++i){
    std::cout << (i+1)
      << " " << d[i]
      << " " << f[i]
      << std::endl;

  }


  // for(auto it = adj_list.begin(); it != adj_list.end(); ++it){
  //   std::cout << ": ";
  //   for(auto jt = (*it).begin(); jt != (*it).end(); ++jt){
  //     std::cout << (*jt) << ' ';
  //   }
  //   std::cout << std::endl;
  // }

  return 0;
}

C++: #include<stdio.h>
#define MAX 101

int G[MAX][MAX], d[MAX], f[MAX];

void adjacency_matrices(int n) {
    int i, j, u, m, k;

    for (i=1; i<=n; i++) {
        scanf("%d", &u);
        scanf("%d", &m);
        for (j=1; j<=m; j++) {
            scanf("%d", &k);
            G[u][k] = 1;
        }
    }
}

int depth_first_search(int t, int i, int n) {
    int j;
    bool get;
    d[i] = t;

    for (j=1; j<=n; j++) {
        if (G[i][j]==1 && d[j]==-1) {
            t = depth_first_search(++t, j, n);
        } 
    }

    f[i] = ++t;

    return t;
}

int main() {
    int n, i, j, t;
    t = 0; 

    scanf("%d", &n);
    for (i=1; i<=n; i++) {
        d[i]=f[i]=-1;
        for (j=1; j<=n; j++) {
            G[i][j] = 0;
        }
    }

    adjacency_matrices(n);

    for (i=1; i<=n; i++) {
        if (f[i]==-1) {
            t = depth_first_search(++t, i, n);
        }
    }

    for (i=1; i<=n; i++) {
        printf("%d %d %d\n", i, d[i], f[i]);
    }

    return 0;
}