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<stdio.h>
#define N 100
#define  GRAY 1
#define BLACK 2
#define WHITE 0
int n,M[N][N];
int color[N],d[N],f[N],tt;
void dfs_visit(int u)
{
  int v;
  color[u] = GRAY;
  d[u] = ++tt;
  for(v = 0;v<n;v++)
  {
    if(M[u][v] == 0)
     continue;
  if(color[v] == 0)
    {
      dfs_visit(v);
    }
}
  color[u] = BLACK;
  f[u] == ++tt;
}
void dfs()
{
  int u;
  for(u = 0;u<n;u++)
     color[u] = 0;
  tt = 0;
  for(u = 0;u<n;u++)
  {
    if(color[u] == 0) dfs_visit(u);
  }
  for(u = 0;u<n;u++)
  {
    printf("%d %d %d\n",u+1,d[u],f[u]);
  }
}
int main ()
{
  int u,v,k,i,j;
  scanf("%d",&n);
  for( i = 0;i<n;i++)
  {  for( j = 0;j<n;j++)
        M[i][j] = 0; }
  for( i =0;i<n;i++)
   {
     scanf("%d %d",&u,&k);
     u--;
     for( j = 0;j<k;j++)
       {
         scanf("%d",&v);
         v--;
         M[u][v] = 1;
       }
   }
   dfs();
  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 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;
	int time = 0;

	st.push(k);
	d[k] = ++time;
	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] = ++time;
			}
		}else{
			f[st.top()] = ++time;
			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;
}

C++: /*
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B    "Depth First Search"?????¨??????
????????????1.5h????§£????????±???????????¢?´¢
?°??????????????????????????????????????????????????§£???????????£????????§???????????¨??????
*/
#include <iostream>
using namespace std;
int a[100][100]={},f[100]={},d[100]={},T[200]={};//a[i][j]???i????§??????¨??????j??????????°????????????????T[i]?????????i???????????????????????????
int main(){
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>a[u][j];
		}
	}
	T[1]=1;//????????????????????????
	f[1]=1;
	int s=1;//s?????¨????????¨???????????????????????????????????????
	for(int time=2;time<=2*n;time++){
		for(int j=0;j<100;j++){
			if(a[T[time-1]][j]==0){//?????????????????????????????????????????????????????????????????????
				d[T[time-1]]=time;
				if(f[T[time-1]]==s){//???????????¨?????¢?´¢???????????£??????
					for(int i=1;i<n;i++){
						if(f[i]==0){//??°????????¨?????????i
							T[time+1]=i;
							time++;
							f[i]=time;
							break;
						}
					}
					s=time;//s?????´??°
				}else{
					T[time]=T[f[T[time-1]]-1];//T[time]??????????????\?????????????????????????????????
				}
				break;
			}
			else if(f[a[T[time-1]][j]]==0){//?????£????????¨???????????????????????????
				f[a[T[time-1]][j]]=time;
				T[time]=a[T[time-1]][j];
				break;
			}
		}
	}
	for(int i=1;i<=n;i++){
		cout<<i<<" "<<f[i]<<" "<<d[i]<<endl;
	}
}

C++: #include <iostream>
#include <queue>

using namespace std;

int G[100][100];
int In[100];
int Out[100];
void init() {
	for (int i = 0; i < 100; i++) {
		for(int j = 0; j < 100; j++)
			G[i][j] = 0;
		In[i] = -1;
		Out[i] = -1;
	}	
}

void dfs(int src);

int main() {
	init();
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			int v_j;
			cin >> v_j;
			G[u - 1][v_j - 1] = 1;
		}
	}
	for (int i = 0; i < n; i++) {
		if (In[i] == -1) dfs(i);		
	}
	for (int i = 0; i < n; i++)
		cout << i + 1 << " " << In[i] << " " << Out[i] << endl;
}

int t = 1;

void dfs(int cur) {
	In[cur] = t;
	t++;
	for (int dst = 0; dst < 100; dst++)
		if (G[cur][dst] == 1 && In[dst] == -1)
			dfs(dst);
	Out[cur] = t;
	t++;
}