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++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C
// stackのパターン
// 実習資料では「srcの訪問時刻は0」となっているが、題意は1である。

#include <iostream>
#include <cstdio>
#include <stack> // 入れたものから出していく引っ越しトラック型の構造。
using namespace std;

int G[110][110];
int n;
int u, k, v;

void make_matrix() {
  fill(&G[0][0], &G[0][0]+110*110, 0);
  scanf("%d", &n);
  for (int i=0; i<n; i++) {
    scanf("%d%d", &u, &k);
    u--;
    for (int j=0; j<k; j++) {
      scanf("%d", &v);
      v--;
      G[u][v] = 1;
    }
  }
}

int timer; // timeだとエラーが出たので。
int d[110]; // 訪問時刻。ナマの数字を入れる(indexを-1処理しない)。
int f[110]; // 終了時刻。ナマの数字を入れる。
int parent[110]; // 訪問する原因となった数字を入れる。ナマの数字を入れる。
int children[110]; // Stackに追加した頂点の数。

void init() {
  timer = 1;
  fill(d, d+110, -1);
  fill(f, f+110, -1);
  fill(parent, parent+110, -1);
  fill(children, children+110, 0);
}

void dfs(int src) {
  // cerr << "dfs root is " << src << endl;
  stack<int> S; // todo訪問先
  S.push(src);
  while (! S.empty()) {
    int cur = S.top(); // 一番最近入れた数字を訪問。
    d[cur] = timer;
    timer++;
    S.pop();
    // cerr << "visiting " << cur << " at the time " << d[cur] << endl;
    for (int i=1; i<=n; i++) { // 節点i
      if (G[cur-1][i-1] == 1 && d[i] == -1) {
	S.push(i);
	parent[i] = cur;
	children[cur]++;
      }
    }
    int hantei = cur;
    while (hantei != -1 && children[hantei] == 0) {
      f[hantei] = timer;
      timer++;
      hantei = parent[hantei];
      children[hantei]--;
    }
  }
}

int main() {
  make_matrix();
  init();
  for (int i=1; i<=n; i++) { // 1から連結していない連結成分にも番号をふる。
    if (d[i] == -1) {
      dfs(i);
    }
  }
  for (int i=1; i<=n; i++) {
    printf("%d %d %d\n", i, d[i], f[i]);
  }
}

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

int M[101][101], cond[101], st[101], en[101], n, t;
stack<int> S;

void setAdj()
{
	int u, k, v;
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v;
			M[u][v] = 1;
		}
	}
}

void dfs(int x)
{
	S.push(x);
	cond[x] = -1; //?¨???????
	st[x] = ++t;

	int i, j;
	while (!S.empty()) {
		int u = S.top();
		for (i = 1; i <= n; i++) {
			if (M[u][i] == 1 && cond[i] == 0) {
				break;
			}
		}
		if (i == n + 1) {
			cond[u] = 1;
			en[u] = ++t;
			S.pop();
		}
		else {
			S.push(i);
			cond[i] = -1;
			st[i] = ++t;	
		}
	}
}

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

	cin >> n;
	t = 0;
	setAdj();
	
	for (int i = 1; i <= n; i++)
		if (cond[i] == 0) dfs(i);

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

C++: #include <iostream>
#include <fstream>
#include <cassert>
#include <string.h>
#include <vector>
#include <map>
#include <stack>

enum Color
{
    kWhite,
    kGray,
    kBlack,
};

// 頂点数.
int n;

// 各頂点の隣接リスト表現.
std::map< int, std::vector<int> > adj_list;

// 各頂点の訪問状態を管理する.
std::vector<Color> c;

// 初回訪問時.
std::vector<int> d;

// 二回目訪問時.
std::vector<int> f;

void makeAdjListFromInput(int n)
{
    for (int i = 0; i < n; ++i)
    {
        int vertex;
        int degree;

        std::cin >> vertex;
        std::cin >> degree;

        assert(vertex <= n);
        assert(degree <= n);

        std::vector<int> adj_vertexes;

        for (int j = 0; j < degree; ++j)
        {
            int adj;
            std::cin >> adj;
            adj_vertexes.push_back(adj - 1);
        }

        adj_list[vertex - 1] = adj_vertexes;
    }
}

int nextVertex(int current)
{
    std::vector< int > adjs = adj_list[current];
    for (std::vector< int >::iterator it = adjs.begin(); it != adjs.end(); ++it)
    {
        if (c[(*it)] == kWhite)
            return (*it);
    }

    // 見つからなかった.
    return 0;
}

void depthFirstSearch()
{
    int counter = 0;
    std::stack<int> tmp_stack;

    // 諸々初期化.
    for (int i = 0; i < n; ++i)
    {
        c.push_back(kWhite);
        d.push_back(0);
        f.push_back(0);
    }

    // 最初の頂点を積む.
    int first = adj_list.begin()->first;
    tmp_stack.push(first);
    c[first] = kGray;
    d[first] = ++counter;

    while (! tmp_stack.empty())
    {
        int current = tmp_stack.top();
        int next = nextVertex(current);
        if (next)
        {
            tmp_stack.push(next);
            c[next] = kGray;
            d[next] = ++counter;
            
        }
        else
        {
            int pop = tmp_stack.top();
            tmp_stack.pop();
            c[pop] = kBlack;
            f[pop] = ++counter;
        }
    }
}

int main()
{
    // std::ifstream ifs("input/alds1_11_b_02.txt");
    // if (!ifs)
    //     assert(false);
    // std::cin.rdbuf(ifs.rdbuf());

    std::cin >> n;

    makeAdjListFromInput(n);

    depthFirstSearch();

    for (std::map< int, std::vector<int> >::iterator it = adj_list.begin(); it != adj_list.end(); ++it)
    {
        int v = it->first;
        std::cout << v + 1 << " " << d[v] << " " << f[v] << std::endl;
    }

    return 0;
}