Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	firstVisitAt int
	finishVisitAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		firstVisitAt: 0,
		finishVisitAt: 0,
		adjs: adjs,
	}
}

func (v *vertex) doesAllAdjsVisited(vertices []vertex) bool {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return false
		}
	}
	return true
}

func (v *vertex) isFirstVisit() bool {
	return v.firstVisitAt == 0
}

func (v *vertex) isVisited() bool {
	return v.firstVisitAt > 0
}

func (v *vertex) nextVertex(vertices []vertex) (vertexId, error) {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return vId, nil
		}
	}
	return vertexId(-1), fmt.Errorf("illegal")
}

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	timestamp = timestamp + 1
	currentVertex := &vertices[currentId-1]
	if currentVertex.isFirstVisit() {
		currentVertex.firstVisitAt = timestamp
	}
	for !currentVertex.doesAllAdjsVisited(vertices) {
		nextVertexId, _ := currentVertex.nextVertex(vertices)
		timestamp = dfs(nextVertexId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	dfs(vertexId(1), 0, vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", vertices[i].id, vertices[i].firstVisitAt, vertices[i].finishVisitAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<vector>
using namespace std;
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B
//
#define N 105
vector<int> nebors[N];//start from 1
int start[N]; // start form 1
int end[N]; //end with 1

void dfs(int k,int d){
	start[k] = d;
	
	//check the adjencit list
	for(int i = 0; i<nebors[k].size(); i++){
		int temp = nebors[k].at(i);
		if(start[temp]==-1)
			dfs(temp,d+1);
	}
	end[k] = 9-d;
}

int main(){
	int n;
	scanf("%d",&n);
	memset(start,-1,sizeof(start));
	memset(end,-1,sizeof(end));
	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);
		}
	}
	dfs(1,1);
	
	for(int i = 1; i<=n; i++){
		printf("%d %d %d\n",i,start[i],end[i]);
	}
}

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

using namespace std;

int N,k[1000];
int v[1000][1000];
int found[1000] = {0},ended[1000] = {0};
int keep;
int checking=0;

void dfs(int cur);

int main() {
	cin >> N;
	for(int i=1;i<N+1;i++) {
		cin >> keep >> k[i];
		for(int j=1;j<k[i]+1;j++) {
			cin >> v[i][j];

		}
	}
	dfs(1);
	while(true) {
		//cout << "processing..." << endl;
		bool flag = false;
		int key = 1;
		for(int i=1;i<N+1;i++) {
			if(found[i] == 0) {
				flag = true;
				key = i;
				break;
			}
		}
		if(flag) {
			dfs(key);
		} else {
			break;
		}
	}
	
	
	for(int i=1;i<N+1;i++) {
		cout << i << " " << found[i] << " " << ended[i] << endl;
	}
	

}

void dfs(int cur) {
	//cout << "process ended" << endl;
	if(!found[cur]) {
		checking++;
		//cerr << "visiting: " << cur << " " << "time: " << checking << endl;
		found[cur] = checking;

	}
	for(int dst=1;dst<N+1;dst++) {
		bool flag = false;
		for(int i=1;i<k[cur]+1;i++) {
			if(v[cur][i] == dst) flag = true;
		}
		if((flag) && (dst != cur) && (!found[dst])) dfs(dst);
	}
	if(!ended[cur]) {
		checking++;
		//cerr << "ended: " << cur << " " << "time: " << checking << endl;
		ended[cur] = checking;
	}
}

C++: #include <iostream>
#include <stack>
using namespace std;
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_visit(int r)
{
  for (int i = 0; i < n; i++)
  {
    nt[i] = 0;
  }

  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()
{
  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_visit(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<cstring>
using namespace std;
#define MAX 100+5
int color[MAX],m[MAX][MAX],start[MAX],stop[MAX],a[MAX]; 
//color[i]中0--白色；1--灰色；2--黑色； 
int num;
int time1=0;
void dfs(int i){
	color[i]=1;start[i]=++time1;
	for(int j=1;j<=num;j++){
		if(m[i][j]==1&&color[j]==0){
			dfs(j);
		}
	}
	color[i]=2;stop[i]=++time1;
	return ;
}
int main(){
	memset(color,0,sizeof(color));
	memset(m,0,sizeof(m));
	cin>>num;
	for(int i=1;i<=num;i++){
		int cnt;
		cin>>a[i]>>cnt;
		for(int j=0;j<cnt;j++){
			int c;cin>>c;
			m[a[i]][c]=1;
		}
	}
	for(int i=1;i<=num;i++){
		if(color[i]==0)
		dfs(i);
	}
	for(int i=1;i<=num;i++){
		cout<<a[i]<<" "<<start[a[i]]<<" "<<stop[a[i]]<<endl;
	}
}

C++: #include <cstdio>
#include <vector>
#include <algorithm>

#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;

int n;
vector<int> g[100];
int t = 1;
int p[100];
int q[100];

void dfs(int i){
	p[i] = t++;
	rep(j, g[i].size()){
		int v = g[i][j];
		if(!p[v]){
			dfs(v);
		}
	}
	q[i] = t++;
}

int main(){
	scanf("%d", &n);
	rep(i, n){
		int u, k;
		scanf("%d%d", &u, &k);
		rep(j, k){
			int v;
			scanf("%d", &v);
			g[u - 1].push_back(v - 1);
		}
	}
	rep(i, n){
		if(!p[i]){
			dfs(i);
		}
	}
	rep(i, n){
		printf("%d %d %d\n", i + 1, p[i], q[i]);
	}
	return 0;
}