Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <iostream>
#include <cstdio>
#include <climits>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#define MAX 1000
#define INFTY 1<<30 // 2^30
using namespace std;
typedef long long llong;

static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, M[N][N];
int color[N], d[N], f[N], tt;
int nt[N];

int next(int u)
{
  for(int v = nt[u]; v < n; v++)
  {
    nt[u] = v+1;
    if(M[u][v]) return v;
  }
  return -1;
}

void dfs_visits(int r)
{
  for(int i = 0; i < n; i++) nt[i] = 0;
  // Initialization
  stack<int> S;
  S.push(r);
  color[r] = GRAY;
  d[r] = ++tt;

  while(!S.empty())
  {
    int u = S.top();
    int v = next(u);
    if(v != -1)
    {
      if(color[v] == WHITE)
      {
        color[v] = GRAY;
        d[v] = ++tt;
        S.push(v);
      }
    }
    else
    {
      S.pop();
      color[u] = BLACK;
      f[u] = ++tt;
    }
  }
}

void dfs()
{
  //Initialization
  for(int i = 0; i < n; i++)
  {
    color[i] = WHITE;
    nt[i] = 0;
  }
  tt = 0;
  for(int u = 0; u < n; u++)
    if(color[u] == WHITE) dfs_visits(u);
  for(int i = 0; i < n; i++)
    cout << i+1 << " " << d[i] << " " << f[i] << endl;
}

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

  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();
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<cstdlib>
#include<string.h>
#include<stack>
using namespace std;

int n;
int m[100][100], d[100], f[100];
int t = 0;
char c[100];
stack<int> s;

int next(int u){
  for(int i = 0; i < n; i++){
    if(m[u][i] == 1 && c[i] == 'w') return i;
  }
  return 0;
}

void dfs(int u){
  s.push(u);
  c[u] = 'g';
  d[u] = ++t;

  while(s.empty() == 0){
    u = s.top();
    int v = next(u);
    if(c[v] == 'w'){
      c[v] = 'g';
      d[v] = ++t;
      s.push(v);
    }
    else{
      s.pop();
      c[u] = 'b';
      f[u] = ++t;
    }
  }
}


int main(){

  cin >> n;

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      m[i][j] = 0;
      c[i] = 'w';
    }
  }

  for(int i = 0; i < n; i++){
    int id, k, x;
    cin >> id >> k;
    for(int j = 0; j < k; j++){
      cin >> x;
      m[i][x - 1] = 1;
    }
  }

  for(int i = 0; i < n; i++){
    if(c[i] != 'b') dfs(i);
  }

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

  return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;

vector<int> graph[100];
int start[100],endt[100];
int cnt;

void dfs(int num){
	start[num] = ++cnt;
	for(int i = 0;i < graph[num].size();i++){
		if(graph[num][i] != num && !endt[graph[num][i]]) dfs(graph[num][i]);
	}
	endt[num] = ++cnt;
}

int main(){
	int n;
	cin >> n;
	for(int i = 0;i < n;i++){
		int now,m;
		cin >> now >> m;
		for(int j = 0;j < m;j++){
			int t;
			cin >> t;
			graph[now - 1].push_back(t - 1);
		}
	}
	dfs(0);
	for(int i = 0;i < n;i++){
		if(!endt[i]) dfs(i);
	}
	for(int i = 0;i < n;i++){
		cout << i + 1 << " " << start[i] << " " << endt[i] << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long i64;typedef vector<int> ivec;typedef vector<string> svec;

static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,M[N][N];
int color[N],d[N],f[N],tt;

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(){
	for(int u=0;u<n;u++) color[u] = WHITE;
	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;
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		scanf("%d %d",&u,&k);
		u--;
		for(int j=0;j<k;j++){
			scanf("%d",&v);
			v--;
			M[u][v] = 1;
		}
	}
	dfs();
	return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;

typedef vector<vector<int>> Graph;

int N;
Graph G;
vector<int> td, tf;
int timestamp;

void dfs(int v){
	td[v] = timestamp++;

	for(int i=0; i<G[v].size(); i++){
		int u = G[v][i];
		if(td[u] == -1){
			dfs(u);
		}
	}

	tf[v] = timestamp++;
}

int main(){
	cin >> N;
	G.resize(N);
	td.resize(N, -1);
	tf.resize(N, -1);

	for(int i=0; i<N; i++){
		int x; cin >> x; x--;
		int k; cin >> k;
		for(int i=0; i<k; i++){
			int y; cin >> y; y--;
			G[x].push_back(y);
		}
	}

	timestamp = 1;

	for(int i=0; i<N; i++) if(td[i] == -1)
		dfs(i);

	for(int i=0; i<N; i++){
		cout << i+1 << " " << td[i] << " " << tf[i] << endl;
	}

	return 0;
}