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 <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

// 深さ優先探索
vector<bool> seen;
int p=0;
int d[200],f[200];
void dfs(const Graph &G, int v) {
    if (!seen[v]) d[v]=p+1;
    seen[v] = true; // v を訪問済にする
    p++;f[v]=p;

    // v から行ける各頂点 next_v について
    for (auto next_v : G[v]) {
        if (seen[next_v]) {
            continue; // next_v が探索済だったらスルー
        }
        dfs(G, next_v); // 再帰的に探索
    }
    p++;f[v]=p;
}

int main() {
   int n;
   cin >> n;
   Graph G(n+1);
   for (int i=0; i<n; i++) {
       int u,k;
       cin >> u >> k;
       for (int j=0; j<k; j++) {
           int v;
           cin >> v;
           G[u].push_back(v);
       }
   }
   seen.assign(n+1,false);
   for (int i=1; i<n+1; i++) {
       if (!seen[i]) {
           dfs(G,i);
       }
   }
   for (int i=1; i<n+1; i++) {
       cout << i << " " << d[i] << " " << f[i] << endl;
   }
}

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

const int MAX_N = 100;

struct Node {
  int v;
  int firstVisitedTime;
  int lastVisitedTime;
  bool visited;
};

void visit(int *count, int n, std::vector<std::list<int> *> *graph, std::vector<struct Node *> *nodes) {
  (*count)++;
  
  struct Node *node = nodes->at(n);

  if (!node->visited) {
    node->firstVisitedTime = *count;
    node->visited = true;
  }  

  //  std::cout << (*count) << " = " << n << std::endl;

  std::list<int> *neighbors = graph->at(n);

  while (!neighbors->empty()) {
    int v = neighbors->front();
    neighbors->pop_front();
    
    if (!nodes->at(v)->visited) {
      visit(count, v, graph, nodes);
    }
  }

  (*count)++;
  node->lastVisitedTime = (*count);

  //  std::cout << (*count) << " = " << n << std::endl;
}

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

  int n = 0;
  std::cin >> n;

  std::vector<std::list<int> *> *graph = new std::vector<std::list<int> *>(n + 1);
  std::vector<struct Node *> *nodes = new std::vector<struct Node *>(n + 1);
  
  for (int i = 1; i <= n; i++) {
    int v = 0;
    std::cin >> v;

    int k = 0;
    std::cin >> k;

    std::list<int> *neighbors = new std::list<int>();

    for (int i = 0; i < k; i++) {
      int a = 0;
      std::cin >> a;

      neighbors->push_back(a);
    }

    graph->at(i) = neighbors;

    struct Node *node = (struct Node *) std::malloc(sizeof(struct Node));

    node->v = i;
    node->firstVisitedTime = 0;
    node->lastVisitedTime = 0;
    node->visited = false;
    
    nodes->at(i) = node;
  }

  int count = 0;
  int start = 1;

  visit(&count, start, graph, nodes);  

  for (std::vector<struct Node *>::iterator iterator = nodes->begin() + 1; iterator != nodes->end(); ++iterator) {
    struct Node *node = *iterator;
        
    std::cout << node->v << " " << node->firstVisitedTime << " " << node->lastVisitedTime << std::endl;
  }
  
  return 0;
}

C++: #include <iostream>
#include <vector>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
using Graph = vector<vector<int>>;

vector<int> d, f;
vector<bool> seen;
void dfs(Graph &G, int v, int &ptr){
  seen[v] = true;
  d[v] = ptr++;
  for (auto next_v : G[v]){
    if (seen[next_v]) continue;
    dfs(G, next_v, ptr);
  }
  f[v] = ptr++;
}

int main() {
  int n;
  cin >> n;
  Graph G(n);
  rep(i, n){
    int u, k;
    cin >> u >> k;
    rep(j, k){
      int v;
      cin >> v;
      G[u-1].push_back(v-1);
    }
  }
  seen.assign(n, false);
  d.assign(n, 0);
  f.assign(n, 0);
  int ptr = 1;
  rep(i, n){
    if (seen[i]) continue;
    dfs(G, i, ptr);
  }
  rep(i, n){
    cout << i+1 << ' ' << d[i] << ' ' << f[i] << endl;
  }
  
  return 0;
}

C++: ///
// File:  alds1_11_b.cpp
// Author: ymiyamoto
//
// Created on Wed Oct 18 00:19:44 2017
//

#include <cstdint>
#include <iostream>

using namespace std;

static uint32_t n;
static uint32_t graph[100][100];
static uint32_t count = 0;
static uint32_t d[100];
static uint32_t f[100];

static void dfs(uint32_t index)
{
  count++;
  d[index] = count;
  for (uint32_t i = 0; i < n; i++) {
    if (d[i] == 0 && graph[index][i] == 1) {
      dfs(i);
    }
  }
  count++;
  f[index] = count;
}

int32_t main()
{
  cin >> n;

  for (uint32_t i = 0; i < n; i++) {
    uint32_t id, k;
    cin >> id >> k;
    for (uint32_t j = 0; j < k; j++) {
      uint32_t v;
      cin >> v;
      graph[id - 1][v - 1] = 1;
    }
  }

  dfs(0);

  for (uint32_t i = 0; i < n; i++) {
    cout << i + 1 << " " << d[i] << " " << f[i] << endl;
  }

  return 0;
}

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 M[N][N], color[N], d[N], f[N], nt[N];
int tt,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] = BLACK;
	d[r] = ++tt;
	
	while(!S.empty()) {
		int u = S.top();
		int v = next(u);
		if(v != -1) {
			   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 j = 0; j < n; j++) {
		if(color[j] == WHITE) {
			dfs_visit(j);
		}
	}
	
	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 i = 0; i < k; i++ ) {
	       cin >> v;
	       v--;
	       M[u][v] = 1;	
	    }		
	}
	
	
	dfs();
	
	return 0;
}