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<cstdio>
using namespace std;
int arisutoteresu[200][200] = {0};
int imap[200][200] = {0};
int n,u[200],k[200];
int GetIt[200]={0};
int FinIt[200]={0};
bool used[200];
int fincou=1;
int Gcounter;
int Fcounter;
int Find;
void dfs(int where){
  fincou++;
  Fcounter++;
  //cout << "where " << where << " " << Find << endl; 
  GetIt[where]=Find;
  //cout << "GetIt[" << where << "] = " << GetIt[where] << endl;
 
  if(k[where] != 0){
    for(int i=0;i<k[where];i++){
      if(!used[imap[where][i]]){
	Gcounter++;
	Find++;

	used[imap[where][i]] = true;
	dfs(imap[where][i]);
	fincou++;
	Fcounter++;

      }
    }
  }
    FinIt[where] = fincou;
     
}
 
int main(){
  
  int ad;
   
  scanf("%d",&n);
  for(int i=0;i<n;i++){
    cin >> u[i];
    cin >> k[u[i]];
    for(int j=0;j<k[u[i]];j++){
      cin >> ad;
      imap[u[i]][j] = ad;
    }
  }
 
 
  for(int j=0;j<200;j++)used[j] = false;
  Gcounter=Fcounter=1;
 
  Find = 1;
  int Index=0;
  bool fin = true;
  fincou = 1;

  
    for(int i=0;i<n;i++){
      if(!used[u[i]]){//cout << "not used" << u[i] << endl;
	used[u[i]]=true;

      dfs(u[i]);
      Find = fincou+1;
      fincou++;      
      }
    }
  
  //dfs(u[0]);   

   
  
  //cout << "counter - " << Find << ", F" << fincou << endl;
  for(int i=0;i<n;i++){
    cout << u[i] << " " << GetIt[u[i]]  << " " << FinIt[u[i]];
    cout << endl;
  }
 
  return 0;
}

C++: #include<cstdio>
#include<queue>
#include<stack>
const int N = 101;
std::queue<int> Q[N];
void dfs(int root, int *tt, int d[], int f[]);
int main() {
    int n; scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        int k;
        scanf("%d%d", &i, &k); //&i, so i--;
        for (int j = 0; j < k; j++) {
            int v; scanf("%d", &v);
            Q[i].push(v);//remember children
            //i starts from 1!. look scanf above
        }
        i--;
    }
    int d[N] = {0}, f[N] = {0}, tt = 0;
    for (int i = 1; i <= n; i++) if(!d[i]) dfs(i, &tt, d, f);//if cannot reach from 0
    for (int i = 1; i <= n; i++) printf("%d %d %d\n", i, d[i], f[i]);
    return 0;
}
void dfs(int root, int *tt, int d[], int f[]) {//from root search
    std::stack<int> S;
    S.push(root);
    d[root] = ++*tt;
    while (!S.empty() ) {
        int u = S.top();
        if (!Q[u].empty() ) {
            int v = Q[u].front();
            Q[u].pop();
            if (d[v] == 0) {
                d[v] = ++*tt;
                S.push(v);
            }
        } else {
            S.pop();
            f[u] = ++*tt;
        }
        
    }
}

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

using namespace std;

static const int N = 100;
int n, m[N][N];
int tm, begT[N], endT[N];
bool visited[N];

int nxt(int u)
{
	for (int v = 0; v < n; ++v)
	{
		if (m[u][v] > 0 && !visited[v]) return v;
	}
	return -1;
}

void dfs_helper(int idx)
{
	stack<int> s;
	s.push(idx);
	begT[idx] = tm++;
	visited[idx] = true;

	while (!s.empty())
	{
		int u = s.top();
		int v = nxt(u);
		if (-1 == v)
		{
			s.pop();
			endT[u] = tm++;
			continue;
		}
		s.push(v);
		begT[v] = tm++;
		visited[v] = true;
	}
}

void dfs()
{
	tm = 1;

	for (int i = 0; i < n; ++i)
	{
		if (!visited[i]) dfs_helper(i);
	}

	for (int i = 0; i < n; ++i)
	{
		cout << i + 1 << " " << begT[i] << " " << endT[i] << endl;
	}
}

int main()
{
	cin >> n;
	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)
		visited[i] = false;

	for (int i = 0; i < n; ++i) {
		int u, d;
		cin >> u >> d;
		for (int j = 0; j < d; ++j)	{
			int v; cin >> v;
			m[u - 1][v - 1] = 1;
		}
	}

	dfs();

	return 0;
}

C++: #if 0

#endif

#include <iostream>
#include <vector>
using namespace std;

int n;
int t; //mytime?????????????????§???????´?
int mytime1[110],mytime2[110]; //?????§??????
int G[110][110];
int c[110];

void dfs(int cur){
	t+=1;
	mytime1[cur]=t;
	c[cur]=1;
	for(int dst=0; dst<n; ++dst){
		if(G[cur][dst]==1&&c[dst]==0){
			cout<<1<<endl;
			dfs(dst);
		}
	} 
	t += 1;
	mytime2[cur]=t;
}


int main()
{
	int G[110][110];
	cin>>n;
	for(int i=0;i<n;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			int tmp;
			cin>>tmp;
			G[u][tmp]=1;
		}
	}
	
	}
	for(int i=0;i<n;++i){
		dfs(i);
		cout<<(i+1)<<' '<<mytime1[i+1]<<" "<<mytime2[i+1] <<endl;
}
}