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>
using namespace std;
int n, adj[101][101], d[101], f[101];
int visited[101]; int  tt=0;

void dfs_visit(int i)
{
  if(visited[i]) return ;
  visited[i] = 1;
  d[i] = ++tt;
  for(int v=1; v<=n; v++)
  {
    if(visited[v]==0 && adj[i][v]==1)
      dfs_visit(v);
  }
  f[i] = ++tt;
}
void dfs(int s)
{
  for(int i=1; i<=n; i++)
  {
    dfs_visit(i);
  }
}

int main()
{
  scanf("%d", &n);
  int u, k, v;
  for(int i=0; i<=n; i++)
  {
    for(int j=0; j<=n; j++)
      adj[i][j] = 0;
  }
  for(int i=0; i<n; i++)
  {
    scanf("%d%d", &u, &k);
    for(int j=0; j<k; j++)
    {
      scanf("%d", &v);
      adj[u][v] = 1;
    }
  }
  for(int i=0; i<=n; i++) visited[i] = 0;
  dfs(1);
  for(int i=1; i<=n; i++)
  {
    printf("%d %d %d\n", i, d[i], f[i]);
  }


  return 0;
}

C++: #include <cstdio>
#include <cstring>

const int MAX = 100;
static int time = 0;
int adj[MAX][MAX];
int discover[MAX];
int finish[MAX];

void visit(int node, int n)
{
  ++time;
  if (discover[node - 1] == 0)
    discover[node - 1] = time;

  for (int i = 0; i < n; ++i)
  {
    if (adj[node - 1][i] == 1 && finish[i] == 0)
      visit(i + 1, n);
  }

  ++time;
  finish[node - 1] = time;
}

int main()
{
  std::memset(adj, 0, sizeof(adj));
  std::memset(discover, 0, sizeof(discover));
  std::memset(finish, 0, sizeof(finish));

  int n;
  scanf("%d", &n);

  int u, k, v;
  for (int i = 0; i < n; ++i)
  {
    scanf("%d%d", &u, &k);
    for (int j = 0; j < k; ++j)
    {
      scanf("%d", &v);
      adj[u - 1][v - 1] = 1;
    }
  }

  visit(1, n);

  for (int i = 0; i < n; ++i)
    printf("%d %d %d\n", i + 1, discover[i], finish[i]);

  return 0;
}

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

typedef struct {
	bool endflag;
	int firsttime;
	int endtime;
}State;

const int Max = 100;
int map[Max + 1][Max + 1] = { 0 };
std::stack<int> st;
std::vector<State> state;


int main()
{
	int n, k, v, x;
	int cnt = 1;

	std::cin >> n;
	for (int i = 1; i <= n; i++) {
		std::cin >> x >> k;
		for (int j = 1; j <= k; j++) {
			std::cin >> v;
			map[x][v] = 1;
		}
	}

	State s = { false,0,0 };
	for (int i = 0; i <= n; i++) {
		state.push_back(s);
	}

	while (1) {
		if (st.empty() == true) {
			if (state[1].endflag == true) {
				break;
			}
			else {
				st.push(1);
				state[1].firsttime = cnt;
				cnt++;
				continue;
			}
		}

		bool flag = false;
		for (int i = 1; i <= n; i++) {
			if (map[st.top()][i] == 1) {
				if (state[i].endflag == false) {
					st.push(i);
					state[i].firsttime = cnt;
					cnt++;
					flag = true;
					break;
				}
			}
		}
		if (flag == true) {
			continue;
		}
		else {
			state[st.top()].endflag = true;
			state[st.top()].endtime = cnt;
			cnt++;
			st.pop();
		}
	}

	for (int i = 1; i <= n; i++) {
		std::cout << i << " " << state[i].firsttime << " " << state[i].endtime << std::endl;
	}

	return 0;
}

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

#define M_PI       3.14159265358979323846   // pi

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> VI;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;

#define rep(a,n) for(ll a = 0;a < n;a++)
#define repi(a,b,n) for(ll a = b;a < n;a++)

using namespace std;

static const ll INF = 1e15;

int main() {
	ll n;
	cin >> n;
	vector<vector<ll>> g(n);
	rep(i, n) {
		int a, k;
		cin >> a >> k;
		rep(j, k) {
			int t;
			cin >> t;
			t--;
			g[i].push_back(t);
		}
	}

	vector<bool> visit(n, false);

	vector<int> start(n);
	vector<int> finish(n);

	int t = 0;

	function<void(int)> dfs = [&](int current){
		if (visit[current]) return;
		visit[current] = true;
		t++;
		start[current] = t;
		for (auto p : g[current]) {
			dfs(p);
		}
		t++;
		finish[current] = t;
		return;
	};
	rep(i, n) {
		dfs(i);
	}
	rep(i, n) {
		cout << i + 1 << " " << start[i] << " " << finish[i] << endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 1

int n, M[N][N];
int color[N], s[N], f[N], ts; 

void dfs_visit(int u) {
    cout << u<< endl;
    int v;
    color[u] = GRAY;
    s[u] = ++ts;
    for (v=0; v<n; v++) {
        if(M[u][v]==0){
            continue;
        }
        if (color[v]==WHITE) {
            dfs_visit(v);
        }
    }
    color[u] = BLACK;
    f[u] = ++ts;
}

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

int main() {
    int u, k, tmp;
    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;
        for (int j=0; j<k; j++) {
            cin >> tmp;
            M[u-1][tmp-1] = 1;
        }
    }
    dfs();
    return 0;
}