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++: //
// Created by tattsun on 2017/02/13.
//

#include <iostream>
#include <vector>

using namespace std;

#define VERTEX_MAX_NUM 101
#define NIL -1

int now = 0;
int n;
int start[VERTEX_MAX_NUM];
int finish[VERTEX_MAX_NUM];
bool visited[VERTEX_MAX_NUM];
vector<int> vertexes[VERTEX_MAX_NUM];

void _dfs(int node) {
    cout << node << endl;
    start[node] = ++now;
    visited[node] = true;

    auto& v = vertexes[node];

    for(auto it = v.begin(); it != v.end(); it++) {
        if(visited[*it])
            continue;
        _dfs(*it);
    }

    finish[node] = ++now;
}

void dfs() {
    _dfs(1);
}

int main() {
    for(int i=0; i<VERTEX_MAX_NUM; i++) {
        start[i] = NIL;
        finish[i] = NIL;
        visited[i] = false;
    }

    cin >> n;

    int u, k, p;
    for(int i=1; i<=n; i++) {
        cin >> u >> k;
        for(int j=0; j<k; j++) {
            cin >> p;
            vertexes[i].push_back(p);
        }
    }

    dfs();

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

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

stack<int> S;
int n, x[10000][10000], a, b, c, d, time=2;
int y[10000][3];

int main() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> b >> c;
		for (int j = 1; j <= c; j++) {
			cin >> d;
			x[i][d] = 1;
		}
	}
	S.push(1);
	y[1][1] = 1;
	while (!S.empty()) {
		a = S.top();
		for (int i = 1; i <= n; i++) {
			if (x[a][i] == 1 && y[i][0] == 0) {
				y[i][0] = 1;
				y[i][1] = time;
				S.push(i);
				goto Exit;
			}
		}
		S.pop();
		y[a][2] = time;
	Exit:;
		time++;
	}
	for (int i = 1; i <= n; i++) {
		cout << i << ' ' << y[i][1] << ' ' << y[i][2] << endl;
	}
	return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<cstring>
#define white 0
#define gray 1
#define black 2
using namespace std;
const int MAXN = 100+10 ;

int a[MAXN][MAXN],flag[MAXN],d[MAXN],f[MAXN],cnt;
int n,u,v,t;

void fun(int x)
{
    flag[x] = gray;
    d[x] = ++cnt;
    for(int i = 1; i <= n; ++i)
    {
        if(a[x][i] && flag[i]==white)
            fun(i);
    }
    flag[x] = black;
    f[x] = ++cnt;
    return;
}

void dfs()
{
    memset(flag,0,sizeof flag);
    for(int i = 1; i <= n; ++i)
    {
        if(flag[i] == white)
            fun(i);
    }
    for(int i = 1; i <= n; ++i)
        cout<<i<<' '<<d[i]<<' '<<f[i]<<'\n';
}
int main(void)
{

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

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


using namespace std;

int timecount = 0;

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap);

int main(){
  int u, i, id, k, j;
  cin >> u;
  unordered_map<int, vector<int> > mymap;

  for (i = 0; i < u; ++i){
    cin >> id >> k;
    vector<int> points;
    for (j = 0; j < k; ++j){
      int a;
      cin >> a;
      points.push_back(a);
    }
    mymap[id] = points;
  }
  
  bool visited[u+1];
  for (j = 1; j <= u; ++j){
    visited[j] = false;
  }
  visited[1] = true;

  int timearray[u+1];
  for (j = 1; j <= u; ++j){
    timearray[j] = 0;
  }
  int timearray_end[u+1];
  for (j = 1; j <= u; ++j){
    timearray_end[j] = 0;
  }

  dfs(1, u, visited, timearray, timearray_end, mymap);

  for (j = 1; j <= u; ++j){
    cout << j << " " << timearray[j] << " " << timearray_end[j]<< endl;
  }

}

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap){
  timecount++;
  timearray[cur] = timecount;

  for(int i = 1; i <= u; ++i){
    
    if((i!=cur)&&(find(mymap[cur].begin(), mymap[cur].end(), i) != mymap[cur].end())&&(!visited[i])){
      visited[i] = true;
      dfs(i, u, visited, timearray, timearray_end, mymap);
    }
  }
  timecount++;

  timearray_end[cur] = timecount;
}