Go: package main

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

const MAX = 101

var f [MAX]int
var d [MAX]int
var list [][]int
var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(u, cnt int) int {
	if d[u] != 0 {
		return cnt
	}

	cnt++
	d[u] = cnt
	for _, next := range list[u] {
		cnt = dfs(next, cnt)
	}
	cnt++
	f[u] = cnt
	return cnt
}

func main() {
	n := scanInt()
	list = make([][]int, n+1)
	for i := 1; i <= n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			n := scanInt()
			list[u] = append(list[u], n)
		}
	}

	cnt := 0
	for i := 1; i <= n; i++ {
		cnt = dfs(i, cnt)
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, d[i])
		fmt.Fprint(w, " ")
		fmt.Fprint(w, f[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

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

int a[101][101];
int n = 0;
int found[101];
int ended[101];
int aaa(int i, int time);

int main() {
  for (int i = 0; i < 101; i++)
    for (int j = 0; j < 101; j++)
	  a[i][j] = 0;
  int u, k, v;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
	for (int j = 0; j < k; j++) {
	  cin >> v;
	  a[u][v] = 1;
	  }
	 }
int time = 0;
for (int i = 0; i < 101; i++){
  found[i] = 0;
  ended[i] = 0;
  }
for (int i = 0; i < n+1; i++) {
  if(found[i] > 0)
    continue;
  time++;
  found[i]=time;
  time=aaa(i,time);
  ended[i]=time;
  }
  
for (int i = 1; i < n+1; i++) {
 cout << i << ' ' << found[i] << ' ' << ended[i] << endl;
 }
 
}
 
int aaa(int i, int time) {
  for (int k = 1; k < n+1; k++) {
    if (a[i][k] == 1 && found[k] == 0) {
	  time++;
	  found[k] = time;
	  time = aaa(k,time);
	  ended[k] = time;
	  }
	 }
	time++;
	return time;
	}

C++: #include <iostream>

using namespace std;

int adja[101][101];
int d[101], f[101], cnt;

void dfs(int u) {
    d[u] = ++cnt;
    for (int i = 0, v; (v = adja[u][i]) > 0; ++i) {
        if (d[v] > 0)
            continue;
        dfs(v);
    }
    f[u] = ++cnt;
}

int main() {
    int n, k, u;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            cin >> adja[u][j];
        }
    }
    for (int i = 1; i <= n; ++i) {
        if (d[i] == 0)
            dfs(i);
        cout << i << " " << d[i] << " " << f[i] << endl;
    }

    return 0;
}