Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	ans := make([][2]int, N)
	time := 0
	found := make(map[int]bool)
	var dfs func(cur int)
	dfs = func(cur int) {
		time++
		ans[cur][0] = time
		found[cur] = true
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if !found[next] {
				dfs(G[cur][i])
			}
		}
		time++
		ans[cur][1] = time
	}
	for i := 0; i < N; i++ {
		if !found[i] {
			dfs(i)
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprint(wtr, i+1)
		for j := 0; j < 2; j++ {
			fmt.Fprint(wtr, " ")
			fmt.Fprint(wtr, ans[i][j])
		}
		fmt.Fprintln(wtr)
	}
	wtr.Flush()
}

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

using namespace std;

int g[102][102];
int d[102], f[102];
int t = 0, n;

int dfs(int x){
    t++;
    //cout<<x<<" s: "<<t<<endl;
    for(int i=1; i<=n; i++){
        if(d[x] == 0) d[x] = t;
       
        if(g[x][i] == 1 && f[i] == 0){
            g[x][i] = 0;
            if(d[i] == 0){
                dfs(i);
                t++;
            }   
        }
        
        if(i == n && f[x] == 0){
            //   cout<<x<<" e: "<<t+1<<endl;
            f[x] = t+1;
        }
    }
    return 0;        
  
}

int main(){
    cin >> n;

    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            g[i][j] = 0;
        }
        d[i] = 0;
        f[i] = 0;
    }
    
    int u,k;
    for(int i=0; i<n; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            int v;
            cin>>v;
            g[u][v] = 1;
        }
    }

    for(int i=1; i<=n; i++){
        if(f[i]==0){
            dfs(i);
            t++;
        }
    }

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

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


int uma[101];
int n=1;
int sore;
int check;
int i;
int shika;
int ima = 1;
int deru=0;
int yagi=1;
int ushi[101];
int kaba[101];
int miti[101][101];
int eda[101][101];
int haji[1001];
int owari[1001];
int main(){
	cin >> shika;
	for (int i = 1; i < shika + 1; i++){
		cin >> uma[i];
		cin >> ushi[uma[i]];
		for (int j = 1; j < ushi[uma[i]] + 1; j++){
			cin >> miti[uma[i]][j];
			eda[uma[i]][miti[uma[i]][j]] = 1;
			eda[miti[uma[i]][j]][uma[i]] = 1;
		}
	}
	//cout << "??\?????????";
	//for (int test = 1; test < shika + 1; test++){ cout << uma[test]<<endl;}//test

	//???????????????????????????
	ima = 1;
	while (true){
		check = 0;
		if (deru == 3){ break; }
		if (deru == 1||deru==2){ deru = 0; }
		yagi = yagi + 1;
	//	cout << yagi << "yagi" << endl;
		if (haji[uma[ima]] == 0){
			haji[uma[ima]] = yagi;
		}
		while (true){
			if (deru > 0){ break; }
			if (eda[uma[ima]][miti[uma[ima]][n]] == 1&&haji[miti[uma[ima]][n]]==0&&owari[miti[uma[ima]][n]]==0){
				eda[uma[ima]][miti[uma[ima]][n]] = 2; 
				//cout << "idou" << ima << "to" << miti[uma[ima]][n] << endl;
				eda[miti[uma[ima]][n]][uma[ima]] = 2;
				ima = miti[uma[ima]][n];
				n = 1;
				break;
			}
			if (eda[uma[ima]][miti[uma[ima]][n]] == 0){
			//	cout << "ikidomari" << endl;
						owari[uma[ima]] = yagi;		
				//cout << "owari" << uma[ima] << yagi << owari[uma[ima]] << endl;
				n = 1;
			//	cout << eda[3][4] <<"shika" << shika <<endl;
				while (true){
					//cout << "edan" << uma[ima] << n << miti[n][uma[ima]] << eda[uma[ima]][miti[n][uma[ima]]] << endl;
					if (deru == 2||deru == 3){ break; }
					for (int sore = 1; sore < shika + 1; sore = sore + 1){
						if (eda[uma[ima]][miti[uma[ima]][sore]] == 1&&owari[miti[uma[ima]][sore]]==0){
							deru = 2;
							n = 1;
							//cout << ima << "move to" << miti[uma[ima]][sore] << endl;
							eda[uma[ima]][miti[uma[ima]][sore]] = 2;
							eda[miti[uma[ima]][sore]][uma[ima]] = 2;
							ima = miti[uma[ima]][sore];
							check = 1;
						}
					}for (int sore = 1; sore < shika + 1; sore = sore + 1){
						if (check==0&&eda[uma[ima]][sore] == 2){
							eda[uma[ima]][sore] = 3;
							eda[sore][uma[ima]] = 3;
							ima = sore;
							deru = 2;
							n = 1;
							//cout << "modoru" << endl;
							break;
						}
					}
					if (n>shika+1){
						for (int i = 1; i < shika + 1; i++){
							if (haji[uma[i]] == 0){
								ima = i;
								//cout << "warp to " << ima << endl;
								deru = 2;
								n = 1;
								break;
							}
							else if (i == shika){
								//cout << "shika" << shika << "i" << i << "shuryo" << endl;
								deru = 3;
								break;
							}
						}
					}
					n = n + 1;
				}
			}
			n = n + 1;
		}
	}
	for (int i = 1; i < shika + 1; i++){
		cout << uma[i] << " " << haji[uma[i]] << " " << owari[uma[i]] << endl;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105

int Mytime = 1;
int d[MAX], f[MAX];
struct Vertex {
	int degree;
	vector<int> adj;
	Vertex(int x = 0) {
		degree = x;
	}
};
vector<Vertex> v;

void DFS(int now) {
	if (d[now] != 0) // 已经搜索过了
		return;
	d[now] = Mytime;
	Mytime++;
	int count;
	for (count = 0; count < v[now].degree; count++) {
		DFS(v[now].adj[count]);
	}
	f[now] = Mytime;
	Mytime++;
}

int main(void) {
	int n, i, j;
	Vertex temp;
	v.push_back(temp);
	cin >> n;
	int u, k, ve;
	for (i = 1; i <= n; i++) {
		d[i] = f[i] = 0;
		cin >> u >> k;
		v.push_back(temp);
		v[i].degree = k;
		while (k--) {
			cin >> ve;
			v[u].adj.push_back(ve);
		}
	}
	for (i = 1; i <= n; i++) {
		DFS(i);
	}
	for (i = 1; i <= n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}

}