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<iostream>
#include<string>
#include<stack>
using namespace std;

void dfs_init();
void dfs(int u);

int n,**List,*deg,*d,*f;
bool **M;
string *color;
stack<int> S;
int vertex,time;

int main(){
	cin>>n;
	List = new int*[n]; M = new bool*[n]; deg = new int[n]; color = new string[n]; d = new int[n]; f = new int[n];
	for(int i=0;i<n;i++) List[i] = new int[n]; for(int i=0;i<n;i++) M[i] = new bool[n];
	for(int i=0;i<n;i++){
		List[i] = List[i]-1;
		M[i] = M[i]-1;
	}
	List = List-1; M = M-1; deg = deg-1; color = color-1; d = d-1; f = f-1;

	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++)
			M[i][j] = false;
		deg[i] = 0; d[i] = 0; f[i] = 0;
	}
	
	int k;
	for(int i=1;i<=n;i++){
		cin>>vertex>>k;
		for(int j=1;j<=k;j++){
			cin>>List[vertex][j];
			M[vertex][List[vertex][j]] = true;
		}
	}

	dfs_init();

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

	for(int i=1;i<=n;i++){
		delete [] (List[i]+1); delete [] (M[i]+1);
	}
	delete [] (List+1); delete [] (M+1);
	delete [] (deg+1); delete [] (color+1); delete [] (d+1); delete [] (f+1);
	cin.get(); cin.get();
}

void dfs_init(){
	for(int i=1;i<=n;i++) color[i] = "WHITE";
	for(int i=1;i<=n;i++){
		if(color[i]=="WHITE"){
			dfs(i);
		}
	}
}

void dfs(int u){
	color[u] = "GRAY";
	d[u] = ++time;
	for(int v=1;v<=n;v++){
		if(M[u][v]==false) continue;
		if(color[v]=="WHITE"){
			dfs(v);
		}
	}
	color[u] = "BLACK";
	f[u] = ++time;
}

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

using namespace std;

#define GRAPH_SIZE 101
#define START_INDEX 1

enum color_t {
  WHITE,
  GRAY,
  BLACK,
};

static uint32_t t = 0;
static color_t state[GRAPH_SIZE];
static vector<uint32_t> graph[GRAPH_SIZE];

void depth_first_search(void (*visited)(uint32_t), void (*invested)(uint32_t))
{
  for (uint32_t i = START_INDEX; i < GRAPH_SIZE; i++) {
    state[i] = WHITE;
  }

  static vector<pair<uint32_t, vector<uint32_t>>> stack;

  for (int32_t index = START_INDEX; index < GRAPH_SIZE; index++) {
    if (state[index] == WHITE) {
      stack.push_back(make_pair(index, graph[index]));
      state[index] = GRAY;
      t++;
      visited(index);

      while (!stack.empty()) {
        pair<uint32_t, vector<uint32_t>> top = stack.back();
        bool found = false;
        for (uint32_t i = 0; i < top.second.size(); i++) {
          uint32_t next = top.second[i];
          if (state[next] == WHITE) {
            found = true;
            state[next] = GRAY;
            t++;
            visited(next);
            stack.push_back(make_pair(next, graph[next]));
            break;
          }
        }

        if (!found) {
          stack.pop_back();
          t++;
          state[top.first] = BLACK;
          invested(top.first);
        }
      }
    }
  }
}

#include <iostream>

static uint32_t visited_time[GRAPH_SIZE];
static uint32_t invested_time[GRAPH_SIZE];

static void visited(uint32_t i)
{
  visited_time[i] = t;
}

static void invested(uint32_t i)
{
  invested_time[i] = t;
}

int32_t main(void)
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t val;
      cin >> val;
      graph[index].push_back(val);
    }
  }

  depth_first_search(visited, invested);

  for (uint32_t i = START_INDEX; i < (START_INDEX + num); i++) {
    cout << i << " " << visited_time[i] << " " << invested_time[i] << endl;
  }

  return 0;
}

C++: #include <iostream>
using namespace std;

static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int M[N][N] = {0}, color[N] = {0}, d[N], f[N], tt = 0, n;

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++) {
    if (color[u] == WHITE) {
      dfs_visit(u);
    }
  }

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

int main(void) {
  int u, v, k, i, j;

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

  return 0;
}