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 <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

int main(){
	int n;
	cin>>n;
	vector<vector<int> > A(n);//????????????????????????-1?????\???????????????
	//??\???
	REP(i,n){
		int u,k;
		cin>>u>>k;
		A[i]=vector<int>(k,0);
		REP(j,k){
			int l;
			cin>>l;
			A[i][j] = l-1;
		}
	}
	//??¢?´¢
	vector<int> s;//??????????????????????????\???
	vector<int> dis(n,0);//??????????????????????????????
	vector<int> fin(n,0);//???????????????????????????
	int time=0;
	while(find(dis.begin(),dis.end(), 0) != dis.end()){
		int saisyo = find(dis.begin(),dis.end(), 0) -  dis.begin();
		//cout<<saisyo<<endl;
		s.push_back(saisyo);//?????????0???????????????
		while(!s.empty()){
		//REP(ss,3){
			int k = s.back();//??????????????????????????????
			if(dis[k]==0){
				time++;
				dis[k]=time;
				//cout<<"dis "<<k<<" / time "<<time<<endl;
			}
			bool isfinish=true;
			for(int i: A[k]){
				//cout<<"?????????"<<i<<endl;
				bool nai = find(s.begin(),s.end(), i) == s.end();
				if(fin[i]==0 && i!=k && nai){
					s.push_back(i);
					isfinish=false;
					break;
				}
			}
			if(isfinish){
				time++;
				fin[k]=time;
				s.pop_back();
				//cout<<"fin "<<k<<" / time "<<time<<endl;
			}
		}
	}
	REP(i,n){
		cout<<i+1<<" "<<dis[i]<<" "<<fin[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>

using namespace std;
typedef long long ll;

const int MAX = 100;

static int u[MAX][MAX];
static int d[MAX];
static int f[MAX];
static int v[MAX];


void seekNode(int n, int& elp) {

	d[n] = elp;
	elp++;
	v[n] = 1;

	for (int i = 0;i < MAX;i++) {
		if (u[n][i] > 0 && v[i] == 0) {
			seekNode(i, elp);
		}
	}


	f[n] = elp;
	elp++;
	return;
}


int main() {

	int n, uid, ap, tmp, elp;
	cin >> n;


	for (int i = 0;i < n;i++) {
		cin >> uid >> ap;
		for (int k = 0;k < ap;k++) {
			cin >> tmp;
			u[uid - 1][tmp - 1] = 1;
		}
	}
	elp = 1;
	for (int i = 0;i < n;i++) {
		if (v[i] == 0)	seekNode(i, elp);
	}

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


	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
//Graph I - Depth First Search
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B

#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

//WHITE -> ????¨?????????????
//GRAY  -> ?¨????????????????(?¨?????????????????¨???????????????????????????????????????§???????????????)
//BLACK -> ?¨??????????????????????(????¨???????????????????????????????????????????)

int n, M[N][N];
int color[N];//?????????????¨??????¶???
int d[N];//????????????
int f[N];//????????????
int tt;//time stamp

//?????°???????????±???????????¢?´¢
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] == WHITE ){
			dfs_visit( v );
		}
	}
	color[u] = BLACK;
	f[u] = ++tt;//?¨?????????????
}
void dfs()
{
	//??¨???????????????color???WHITE????¨????
	for( int u = 0; u < n; u++ ) color[u] = WHITE;
	tt = 0;
	for( int u = 0; u < n; u++ ){
		//????¨??????? u ?????°??????????§?????????¨????????±???????????¢?´¢
		if( color[u] == WHITE ) dfs_visit( u );
	}
	for( int u = 0; u < n; u++ ){
		cout << u + 1 << " " << d[u] << " " << f[u] << endl;
	}
}
int main()
{
	int u;//???????????????
	int k;//??????u?????£??\?????????????????????
	int v;//??????u????¬???°

	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 <stdio.h>
#include <iostream>
#include <utility>
#include <algorithm>
#include <math.h>
#include <vector>
#include <list>

using namespace std;
int n;
list<int> adj[101];
int d[101] = {};
int f[101] = {};

void DFS(int v)
{
    static int num = 1;
    d[v] = num++;
    while (!adj[v].empty())
    {
        if (d[adj[v].front()] == 0)
            DFS(adj[v].front());
        adj[v].pop_front();
    }
    f[v] = num++;
}

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

int main()
{
    int u, k, v;
    cin >> n;

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

    DFS(1);

    print();

    return 0;
}