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>
#define MAX 101

using namespace std;

bool flag[MAX][MAX];
int t[MAX][2];
int n;

void dfs(int num){
	static int cnt = 1;
	
	if(t[num][0] == 0)t[num][0] = cnt++;
	else return;
	for(int i=1;i<=n;++i){
		if(flag[num][i] == true){
			dfs(i);
		}
	}
	t[num][1] = cnt++;
}

int main(){
	int u, k, v, i, j; 
	
	cin >> n;
	for(i=1;i<=n;++i){
		cin >> u >> k;
		for(j=0;j<k;++j){
			cin >> v;
			flag[u][v] = true;
		}
		 
	}
	for(int i=1;i<=n;++i)dfs(i);
	for(int i=1;i<=n;++i)cout << i << " " << t[i][0] << " " << t[i][1] << endl;
	
	return 0;
}

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

using namespace std;


struct Edge{ //??°????????????
public:
    int src, dst;
    int weight;
    Edge(int a,int b):src(a),dst(b),weight(1){} //?????????????????????
    void setWeight(double x){
        weight = x;
    }
};
typedef vector<Edge> Edges; //???????????£??\?????????
typedef vector<Edges> Graph; //??°???????????£??\???????????¨???

typedef vector<int> Array; //??´??°?????????
typedef vector<Array> Matrix; //??´??°???????????£??\?????????

const int N = 100;
const int White = 0, Gray = 1, Black =2;

int n;
int tt = 0;
Matrix M(N,Array(N,0));
vector<int> d(N,0), f(N,0);
vector<int> color(N,0);


vector<int> nt(N,0);//???????????????????????????????????§?????????????¨???¶??????

int next(int u){ //???u?????\?¶??????????????????????????????????
    if (nt[u]!= n) {
        for(int i = nt[u];i<n;i++){
            if(M[u][i]){
                nt[u] = i+1;
                return i;
            }
        }
        return -1;
    } else {
        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] = Gray;
    d[r] = ++tt;
    
    while (!S.empty()) {
        int v = S.top();
        int w = next(v);
        if (w != -1) {
            if (color[w]==White) {
                color[w] = Gray;
                d[w] = ++tt;
                S.push(w);
            }
        } else {
            S.pop();
            color[v] = Black;
            f[v] = ++tt;
        }
    }
    
}

void dfs(){
    for (int i = 0; i<n; i++) {
        color[i] = White;
        nt[i] = 0;
    }
    for (int i = 0; i<n; i++) {
        if (color[i]==White) {
            dfs_visit(i);
        }
    }
    for (int i = 0; i<n; i++) {
        cout << i+1 << " " << d[i] << " " << f[i] << endl;
    }
}


int main(){
    
    int k,v,w;
    
    cin >> n; //??°????????????????????\???
    
    for (int i=0; i<n; i++) { //??????????¬???°?????????????????\??? ???????????\??????????????£??\??????????????£??\?????????????´?
        cin >> w >> k;
        for (int j=0; j<k; j++) {
            cin >> v;
            M[w-1][v-1] = 1; //?????????
        }
    }
    
    dfs();
    
    return 0;
}

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

// 総数を1000000007で割った余り
const long long mod = 1e9 + 7;

using ll  = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
// #define SORT(v, n) stable_sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

const int N     = 100;
int       white = 0;
int       gray  = 1;
int       black = 2;

int n, m[N][N];
int color[N], d[N], f[N], tt;

// 再帰による深さ優先探索
void dfs_visit(int u) {
    color[u] = gray;
    d[u]     = ++tt;  //最初の訪問
    rep(v, n) {
        if (m[u][v] == 0) continue;
        if (color[v] == white) {
            dfs_visit(v);
        }
    }
    color[u] = black;
    f[u]     = ++tt;  // 訪問の完了
}

void dfs() {
    //初期化
    rep(u, n) color[u] = white;
    tt                 = 0;
    rep(u, n) {
        // 未訪問のuを始点として深さ優先探索
        if (color[u] == white) dfs_visit(u);
    }
    rep(u, n) { cout << u + 1 << " " << d[u] << " " << f[u] << endl; }
}

// 再帰による深さ優先探索
int main() {
    int u, v, k;
    cin >> n;
    rep(i, n) rep(j, n) m[i][j] = 0;

    rep(i, n) {
        cin >> u >> k;
        u--;
        rep(j, k) {
            cin >> v;
            v--;
            m[u][v] = 1;
        }
    }
    dfs();

    return 0;
}

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

int r[101][101];
int d[101], f[101], num, visit[100]={0}, p=1;

void dfs(int n){
    if(visit[n]!=1){
        visit[n] = 1;
        d[n] = p++;
        for(int i=1; i<num+1; i++)
            if(r[n][i]==1) dfs(i);
        f[n] = p++;
    }
}

int main(void){
    int u, k, v;
    cin >> num;
    for(int i=0; i<num; i++){
        cin >> u >> k;
        for(int j=0; j<k; j++){
            cin >> v;
            r[u][v]=1;
        }
    }
    for(int i=1; i<num+1; i++){
        if(visit[i]!=1) dfs(i);
    }
    for(int i=1; i<num+1; i++)
        cout << i << " " << d[i] << " " << f[i] << endl;
    return 0;
}