Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

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

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

C++: #include <iostream>
#include <stack>
using namespace std;
const int N = 100;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;

int n,M[N][N];
int color[N],d[N],f[N],tt;
int nt[N];

// u?????£??\??????v?????????????????????
int next(int u){
    for (int v = nt[u]; v < n ; v++) {
        nt[u] = v +1;
        if(M[u][v]) return v;
    }
    return -1;
}

//with stack

void dfs_visit (int r){
    for (int i = 0; i < n ; ++i) nt[i] = 0;

    stack<int> S;
    S.push(r);
    color[r] = GRAY;
    tt ++; d[r] = tt;

    while(! S.empty()){
        int u = S.top();
        int v = next(u);
        if( v != -1){
            if(color[v] == white) {
                color[v] = GRAY;
                d[v] = ++tt;
                S.push(v);
            }
        }else{
            S.pop();
            color[u] = BLACK;
            f[u] = ++ tt;
        }
    }
}

void dfs(){
    int u;
    for (u = 0; u < n; ++u) {
        color[u] = white;
    }
    tt = 0;

    for (int u = 0; u < n ; ++u) {
        //????¨???????u????§??????¨????????±???????????¢?´¢
        if(color[u] == white) dfs_visit(u);
    }
    for (int u = 0; u < n ; ++u) {
        cout << u+1 << " " << d[u] << " " << f[u] << endl;
    }
}

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

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;
}