Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

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;
}