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 <cstdio>
#include <iostream>
#include <cmath>
#include <ctype.h>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <list>
#include <cstring>
#include <stack>

using namespace std;

#define mod 1000000007

int n;
int d[101], v[101];
int graph[101][101] = {};

int solve(int k, int cnt)
{
	d[k] = cnt;
	int nowcnt = cnt;
	for(int i = 0; i < n; i++){
		if(d[i] < 0 && graph[k][i] > 0) nowcnt = solve(i, nowcnt + 1);
	}
	return v[k] = nowcnt + 1;
}

int main()
{
	cin >> n;
	for(int i = 0; i < n; i++){
		d[i] = -1;
		v[i] = -1;
		int u, k;
		cin >> u >> k;
		u--;
		for(int j = 0; j < k; j++){
			int v;
			cin >> v;
			v--;
			graph[u][v] = 1;
		}
	}
	int nowcnt = 1;
	for(int i = 0; i < n; i++){
		if(d[i] < 0) nowcnt = solve(i, nowcnt) + 1;
	}
	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << d[i] << " " << v[i] << endl;
	}
}

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

using namespace std;

int curTime = 1;
void dfs(int cur, const vector<vector<bool> >& a, vector<int>& d, vector<int>& f, vector<bool>& visited){
  visited[cur] = true;
  d[cur] = curTime;
  curTime++;
  // cerr << "visiting [" << cur << "], time = " << curTime << endl;

  for(int dst = 1; dst <= a.size(); dst++){
    if(a[cur][dst] && !visited[dst]) {// cur????????¶??????????????????????????????
      dfs(dst, a, d, f, visited);
    }
  }
  f[cur] = curTime;
  curTime++;
  return;
}

int main(){
  int n;
  cin >> n;
  vector<vector<bool> > a(n+1, vector<bool>(n+1, false));
  for(int i = 1; i <= n; i++){
    int u;
    cin >> u;
    int k;
    cin >> k;
    for(int j = 0; j < k; j++){
      int v;
      cin >> v;
      a[i][v] = true;
    }
  }

  vector<bool> visited(n+1, false);
  vector<int> d(n+1), f(n+1);

  for(int i = 1; i <= n; i++){
    if(!visited[i]){
      dfs(i, a, d, f, visited);
    }
  }

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

C++: #include<iostream>
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

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]==WHITE){dfs_visit(v);}
    }
    color[u]=BLACK;
    f[u]=++tt;
}

void dfs(){
    int u;
    for(u=0; u<n; u++){
        color[u]=WHITE;
    }
    tt=0;
    for(u=0; u<n; u++){
        if(color[u]=WHITE){dfs_visit(u);}
    }
    for(u=0; u<n; u++){
        printf("%d %d %d",u+1,d[u],f[u]);
    }
}

int main(){
    int i,j,k,u,v,n;
    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 <iostream>
using namespace std;

const int MAX = 100;
int n;
int G[MAX + 1][MAX + 1];
int bt[MAX + 1], et[MAX + 1];
int states[MAX + 1];
int t = 0;

void dfs(int id) {
  if (states[id] == 1) return;
  states[id] = 1;
  bt[id] = ++t;
  for (int i = 0; i < n; i++) {
    if (G[id][i] == 1 && states[i] == 0) {
      dfs(i);
    }
  }
  et[id] = ++t;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;

  int u, v, k;

  for (int i = 0; i < n; i++) {
    states[i] = 0;
    for (int j = 0; j < n; j++) {
      G[i][j] = 0;
    }
  }

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

  for (int i = 0; i < n; i++) {
    dfs(i);
  }

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

  return 0;
}

C++: #include<bits/stdc++.h>

using namespace std;

typedef vector<int> vec;
typedef vector<vec> Graph;

Graph G(110);
int T,In[110],Out[110];
bool used[110];

void dfs(int x)
{
	used[x]=true;
	In[x]=++T;
	for(int i=0;i<G[x].size();i++)
		if(!used[G[x][i]])
			dfs(G[x][i]);
	Out[x]=++T;
}

int main()
{
	int n;
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		int u,t;
		scanf("%d%d",&u,&t);
		for(int j=0;j<t;j++)
		{
			int v;
			scanf("%d",&v);
			G[u].push_back(v);
		}
	}
	memset(used,false,sizeof(used));
	T=0;
	dfs(1);
	for(int i=1;i<=n;i++)
		printf("%d %d %d\n",i,In[i],Out[i]);
	return 0;
}