Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	ans := make([][2]int, N)
	time := 0
	found := make(map[int]bool)
	var dfs func(cur int)
	dfs = func(cur int) {
		time++
		ans[cur][0] = time
		found[cur] = true
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if !found[next] {
				dfs(G[cur][i])
			}
		}
		time++
		ans[cur][1] = time
	}
	for i := 0; i < N; i++ {
		if !found[i] {
			dfs(i)
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprint(wtr, i+1)
		for j := 0; j < 2; j++ {
			fmt.Fprint(wtr, " ")
			fmt.Fprint(wtr, ans[i][j])
		}
		fmt.Fprintln(wtr)
	}
	wtr.Flush()
}

C++: #include <iostream>
#include <cstring>
#include <cstdlib>
#include <sstream>
#include <stack>
#include <queue>
#include <list>
#include <stdio.h>
#include <algorithm>
#define MAX 100000
using namespace std;
typedef long long ll;
int map[255][255];
int f[255],d[255],time=0;
bool vis[255];
void dfs(int n,int u)
{
	if(vis[u]) return;
	vis[u]=true;
	time++;
	d[u]=time;
	for(int i=1;i<=n;i++)
	{
		if(map[u][i]) dfs(n,i);
	}
	time++;
	f[u]=time;
	return; 
}
int main()
{	
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
		{
			map[i][j]=0;
		}
	for(int i=0;i<n;i++)
	{
		int cur,k,u;
		cin>>cur>>k;
		while(k--)
		{
			cin>>u;
			map[cur][u]=1;
		}
	}
	for(int i=1;i<=n;i++)
	{
		vis[i]=false;
	}
	for(int i=1;i<=n;i++)
	{
		if(!vis[i]) dfs(n,i);
	}
	for(int i=1;i<=n;i++)
	{
		cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	}
	return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<vector>
#include<stack>
using namespace std;
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B
//if it is not fully connected component
#define N 105
vector<int> nebors[N];//start from 1
int start[N]; // start form 1
int end[N]; //end with 1
int vis_nei[N]; // neighbor
stack<int> s;
int dfs(int k,int d){
	start[k] = (++d);

	for(int i = 0; i<nebors[k].size(); i++){
		int temp = nebors[k].at(i);
		if(start[temp]==-1) d = dfs(temp,d);
	}
	end[k] = (++d);
	return d;
}

int main(){
	int n;
	scanf("%d",&n);
	memset(start,-1,sizeof(start));
	memset(end,-1,sizeof(end));
	memset(vis_nei,-1,sizeof(vis_nei));
	//vis_nei
	for(int i = 1; i<=n; i++){
		int id,num;
		scanf("%d %d",&id, &num);
		for(int j = 0; j<num; j++){
			int temp;
			scanf("%d",&temp);
			nebors[id].push_back(temp);
			//nebors[temp].push_back(id);
		}
	}
	//check each node for the (unfully connected)
	int d = 0;
	for(int i = 1; i<n; i++){
		if(start[i]==-1){
			d = dfs(i,d);
		}
	}
	
	for(int i = 1; i<=n; i++){
		printf("%d %d %d\n",i,start[i],end[i]);
	}
}

C++: #include <iostream>
using namespace std;
typedef long long ll;
#define int ll

int g[105][105], d[105], f[105];
int presenttime = 1, n;
bool is_search[105];

void bfs(int p) {
  d[p] = presenttime++;
  is_search[p] = true; // ??????????????§?????§??????

  for (int i = 0; i < n; i++) {
    if(is_search[i] == false && g[p][i] && p != i) bfs(i);
  }
  if (f[p] == 0) f[p] = presenttime++;
}

signed main(void) {
  int u, k, v;

  fill(is_search, is_search + n, false);

  cin >> n;

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

  int s = 0, i;

   while(1) {
    s = 0;
    bfs(s);

    for (i = 0; i < n; i++) {
      if (is_search[i] == false) {
        s = i;
        break;
      }
    }
    if(i == n) break;
   }

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

C++: #include<bits/stdc++.h>
#define N 105
using namespace std;
int n,u,k,v,e[N][N],cnt;
int ans1[N],ans2[N];
bool used[N];

void dfs(int x){
  if(used[x])return;
  used[x]=true;
  ans1[x]=cnt++;
  for(int i=0;i<n;i++)
    if(e[x][i])dfs(i);
  ans2[x]=cnt++;
}

int main(){
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    for(int j=0;j<k;j++)
      cin>>v,e[u-1][v-1]=1;
  }
  cnt=1;
  dfs(0);
  for(int i=0;i<n;i++){
    cout<<i+1<<' '<<ans1[i]<<' '<<ans2[i]<<endl;
  }
  return 0;
}

C++: #include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;
#define MAX 100
#define WHITE 1
#define GRAY 2
#define BLACK 3

int n;
int graph[MAX][MAX];
stack<int> st;
int *d,*f,*v;
int *color;
int t = 0;

int next(int k){
	for(int i = v[k];i < n;i++){
		v[k]++;
		if(color[i] == WHITE && graph[k][i] == 1) return i;
	}
	return -1;
}

void dfs(int k){
	for(int i = 0;i < n;i++) v[i] = 0;

	st.push(k);
	d[k] = ++t;
	color[k] = GRAY;

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


int main(){
	cin >> n;
	//?????????
	color = new int[n];
	d = new int[n];
	f = new int[n];
	v = new int[n];
	for(int i = 0;i < n;i++){
		color[i] = WHITE;
		d[i] = 0;
		f[i] = 0;
		for(int j = 0;j < n;j++){
			graph[i][j] = 0;
		}
	}
	//data input
	for(int i = 0;i < n;i++){

		int t,k,p;

		cin >> t >>  k;
		for(int j = 0;j < k;j++){
			cin >> p;
			p--;
			graph[i][p] = 1;
		}
	}
	for(int i = 0;i < n;i++){if(color[i] == WHITE) dfs(i);}
	for(int i = 0;i < n;i++){
		cout << i+1 << " " << d[i] << " " << f[i] << endl;
	}
	return 0;
}