Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

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

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve

const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 最初にiを訪問した時刻。発見時刻
//f[i]: iの隣接リストを訪問し終えた時刻。完了時刻
var color, d, f [MAX]int

func dfs_visit(u int) {
	color[u] = GRAY
	time++
	d[u] = time
	//隣接を調べる
	for v := 0; v < n; v++ {
		if M[u][v] == 0 {
			continue
		}
		//隣接するvが、未訪問だった場合
		if color[v] == WHITE {
			dfs_visit(v)
		}
	}
	//訪問完了処理
	color[u] = BLACK
	time++
	f[u] = time
	//訪問完了
}

func dfs() {
	//初期化
	for u := 0; u < n; u++ {
		color[u] = WHITE
	}
	time = 0

	//未訪問のuを始点として、深さ優先探索
	for u := 0; u < n; u++ {

		if color[u] == WHITE {
			dfs_visit(u)
		}
	}

	for u := 0; u < n; u++ {
		fmt.Println(u+1, d[u], f[u])
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	dfs()

}

C++: #include <bits/stdc++.h>
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

int n;
vector< vector<int> > graph(110, vector<int>());
vector<int> fst(110, -1);
vector<int> snd(110, -1);

int abstime = 0;
void dfs(int now) {
    // cout << "ok" << endl;
    if(fst.at(now) != -1) return;
    abstime++;
    fst.at(now) = abstime;
    for(int i = 0; i < graph.at(now).size(); ++i) {
        dfs(graph.at(now).at(i));
    }
    abstime++;
    snd.at(now) = abstime;
}

int main() {
    cin >> n;
    for(int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        u--;
        for(int j = 0; j < k; ++j) {
            int v;
            cin >> v;
            v--;
            graph.at(u).push_back(v);
        }
    }

    for(int i = 0; i < n; ++i) {
        dfs(i);
    }

    for(int i = 0; i < n; ++i) {
        cout << i+1 << " " << fst.at(i) << " " << snd.at(i) << endl;
    }
}

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

using namespace std;

int N;
vector<vector<int>> tree;
vector<pair<int,int>> times;

void stamp(int ind, int &time){
	//cout << ind << "," << time << endl;
	if(times[ind].first == 0) times[ind].first = time++;
	else return;
	if(tree[ind].size() == 0){
		times[ind].second = time++;
		//cout<<"break! " << ind << endl;
		return;
	}
	for(int i=0;i<tree[ind].size();i++){
		//cout << tree[ind][i] << endl;
		stamp(tree[ind][i],time);
	}
	//cout << ind << ":" << time << endl;
	times[ind].second = time++;
}

int main(){
	cin >> N;
	tree = vector<vector<int>>(N+1);
	times = vector<pair<int,int>>(N+1,make_pair(0,0));

	for(int i=1;i<N+1;i++){
		int ind, branch;
		cin >> ind >> branch;
		vector<int> tmp(branch);
		for(int j=0;j<branch;j++){
			int in;
			cin >> in;
			tmp[j] =  in;
		}
		tree[ind] = tmp;
	}

	int time = 1;
	stamp(1,time);

	int i = 1;
	for(auto st:times){
		if(i<=N)
			cout << i << " " << times[i].first << " " << times[i].second << endl;
		i++;
	}

	return 0;
}

C++: /*16D8103008D 西村悠輝　nissy0507barista  alds11_B*/ 

#include<iostream>

#define MAX 100
using namespace std;

int n,v,k,u; ///超点数、頂点番号、出次数、隣接
int d[MAX], f[MAX];///タイムスタンプ
int a[MAX][MAX];
int cnt=0;
int flag[MAX]; ///通ったかどうか

void dfs(int x) {

	if (flag[x] == 1)return;
	cnt++;
	d[x] += cnt;
	flag[x] = 1;
	for (int i = 1; i <= n; i++) {
		if (a[x][i] == 1 && flag[i] == 0) dfs(i);
	}
	cnt++;
	f[x] += cnt;

}

int main(void)
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> v >> k;
		for (int j = 0; j < k; j++) {
			cin >> u ;
			a[v][u]=1;
		}
	}
	
	for (int i = 1; i <= n; i++) dfs(i);

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

	return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <stack>
#define N 110
using namespace std;
stack<int> s;
int n;
int m[N][N];
int used[N];
int time = 1;
int bb_start[N];
int bb_end[N];
int getnext(int u){
    for(int i = 1; i <= n; i++){
        if(m[u][i] == 1 && used[i] == 0) return i;
    }
    return -1;
}
void dfs(int root){
    used[root] = 1;
    bb_start[root] = time++;

    while(!s.empty()) s.pop();
    s.push(root);
    while(!s.empty()){
        int u = s.top();
        int v = getnext(u);
        if(v != -1 && used[v] == 0){
            used[v] = 1;
            bb_start[v] = time++;
            s.push(v);
        } else{
            bb_end[u] = time++;
            s.pop();
        }
    }
}
int main(){
    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++) used[i] = 0;
    scanf("%d", &n);
    for(int p = 0; p < n; p++){
        int node, k;
        scanf("%d %d", &node, &k);
        for(int i = 0; i < k; i++){
            int b;
            scanf("%d", &b);
            m[node][b] = 1;
        }
    }
    for(int i = 1; i <= n; i++) if(used[i] == 0) dfs(i);
    for(int i = 1; i <= n; i++){
        printf("%d %d %d\n", i, bb_start[i], bb_end[i]);
    }
    return 0;
}

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

int n, dd[101], f[101], tmap[101][101];
int color[101], t = 1;
stack<int> S;

int a(){
	int d = S.top();
	dd[d] = t;
	t++;
	color[d] = 1;
	for (int i = 1; i <= n; i++){
		if (color[i] == 0 && tmap[d][i] == 1){
			S.push(i);
			a();
		}
	}
	
	f[d] = t;
	t++;
	return 0;
}


int main(){
	cin >> n;
	for (int i = 0; i < 100; i++){
		dd[i] = f[i] = color[i] = 0;
		for (int j = 0; j < 100; j++){
			tmap[i][j] = 0;
		}
	}

	int u, k, v;

	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			tmap[u][v] = 1;
		}
	}
	for (int i = 1; i <= n; i++){
		if (color[i] == 0){
			S.push(i);
			a();
		}
	}
	for (int i = 1; i <= n; i++){
		cout << i << " " << dd[i] << " " << f[i] << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<climits>
#include<vector>
#include<list>
#include<functional>
#include<algorithm>
#include<string>
#include<cmath>
#include<complex>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<(n);i++)
#define INF (int)1e9
#define INFL (ll)1e11
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

vector<int> d(100, 1), f(100);

int dfs(vector<vector<int>> a, int s) {
	int n = a.size();
	int res = 0;
	REP(j, n) {
		if (d[j] == 1 && a[s][j]) {
			if (res == 0) {
				d[j] = d[s] + 1;
			}
			else {
				d[j] = res;
			}
			res = dfs(a, j) + 1;
		}
	}
	if (res == 0) return f[s] = d[s] + 1;
	return f[s] = res;
}

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

	int n;
	cin >> n;
	vector<vector<int>> a(n, vector<int>(n, 0));
	REP(i, n) {
		int u, k;
		cin >> u >> k;
		u--;
		REP(j, k) {
			int v;
			cin >> v;
			a[u][--v] = 1;
		}
	}
	dfs(a, 0);
	REP(i, n) {
		cout << i + 1 << " " << d[i] << " " << f[i] << "\n";
	}
	
	return 0;
}