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<cstdio>
#include<cstring>
#include<vector>
#include<queue>
#include<algorithm>
#include<cmath>
#include<climits>
#include<string>
#include<set>
#include<numeric>
#include<map>
#include<iostream>
using namespace std;
#define rep(i,n) for(int i = 0;i<((int)(n));i++)
#define reg(i,a,b) for(int i = ((int)(a));i<=((int)(b));i++)
#define irep(i,n) for(int i = ((int)(n)-1);i>=0;i--)
#define ireg(i,a,b) for(int i = ((int)(b));i>=((int)(a));i--)
typedef long long ll;
typedef pair<ll, ll> mp;


int visitTime = 1;
int d[101]={},f[101]={},n[101],v[101][101],id;


void dfs(int cur) { // cur????¨????
	d[cur] = visitTime;// cur????¨??????????????¨????
	visitTime += 1;
	rep(i,n[cur]){ // ??¨????????? v[cur][i] ????????????
		if(d[v[cur][i]]==0){ // v[cur][i] ???????¨??????????
			dfs(v[cur][i]);
		}
	}
	f[cur] = visitTime;// cur ????¨????????????????????¨????
	visitTime += 1;
	// ??¢??°??????????????§???????????? (?????¢??°)
}

int main(void){
	int N;
	cin>>N;
	rep(i,N){
		cin>>id;
		cin>>n[id];
		rep(j,n[id])cin>>v[id][j];
	}
	reg(i,1,N){
		if(d[i]==0){
			dfs(i);
		}
	}
	reg(i,1,N)cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	return 0;
}

C++: #include <stdio.h>
#include <stdlib.h>

bool adj[105][105] = {0};
int in[105];
int out[105];

int cnt = 1;

void dfs(int now){
    in[now] = cnt++;
    for(int i = 1; i<=100; i++){
        if(adj[now][i] && !in[i])
            dfs(i);
    }
    out[now] = cnt++;    
}


int main(){

    int n = 0;
    scanf("%d", &n);

    for(int i = 1; i<=n; i++){
        int v, c;
        scanf("%d %d", &v, &c);

        while(c--){
            int w = 0;
            scanf("%d", &w);
            adj[v][w] = true;
        }
    }
    
    dfs(1);
    
    for(int i = 1; i<=n; i++){
        printf("%d %d %d\n", i, in[i], out[i]);
    }

    //system("PAUSE");
    return 0;

}

C++: #include<bits/stdc++.h>
using namespace std;

int n,u,k,v;
int g[102][102];
int d[102],f[102];
int sn[102];
int cnt=1;

void dfs(int x);

int main(){
  memset(d,0,sizeof(d));
  cin>>n;
  for(int i=1;i<=n;i++){
    cin>>u>>k;
    sn[i]=0;
    for(int j=1;j<=k;j++){
      cin>>v;
      g[u][v]=1;
    }
  }
  
  dfs(1);

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

  return(0);
}

void dfs(int x){
  
  sn[x]=1;
  d[x]=cnt;
  cnt++;
  
  for(int i=1;i<=n;i++){
    if(g[x][i]==1 && sn[i]==0){
      dfs(i);
    }
  }

  f[x]=cnt;
  cnt++;

}

C++: #include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i=0; i<(n); ++i)
using ll = long long;
using P = pair<int, int>;

const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
const int MAX = 103;
int G[MAX][MAX];
int color[MAX];
int nt[MAX], d[MAX], f[MAX];
int tt, n;

int next(int u) {
  for (int v=nt[u]; v<n; v++) {
    nt[u] = v + 1;
    if (G[u][v]) return v;
  }
  return -1;
}

void dfs_visit(int r) {
  memset(nt, 0, sizeof(nt));
  stack<int> S;
  S.push(r);
  color[r] = GRAY;
  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() {
  memset(color, WHITE, sizeof(color));
  memset(nt, 0, sizeof(nt));
  tt = 0;

  rep(u,n) {
    if (color[u] == WHITE) dfs_visit(u);
  }
  rep(i,n) {
    cout << i+1 << ' ' << d[i] << ' ' << f[i] << endl;
  }
}

int main() {

  cin >> n;
  rep(i,n) memset(G[i], WHITE, sizeof(G[i])); // init
  int u, k;
  rep(i,n) {
    cin >> u >> k;
    rep(j,k) {
      int t;
      cin >> t;
      G[i][t-1] = 1;
    }
  }

  dfs();

  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

vector<vector<int>> g;
vector<int> f,d;
vector<bool> seen;
int tim = 1;

void dfs(int now){
  seen[now] = true;
  d[now] = tim;
  tim++;
  
  for(int next: g[now]){
    if(seen[next]){
      continue;
    }
    dfs(next);
  }
  f[now] = tim;
  tim++;
}

int main(){
  int n;
  cin >> n;
  g = vector<vector<int>>(n);
  f = d = vector<int>(n);
  seen = vector<bool>(n,false);

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

  for (int i = 0; i < n; i++)
  {
    if(!seen[i]) dfs(i);
  }
  for (int i = 0; i < n; i++)
  {
    cout << i+1 << " " << d[i] << " " << f[i] << endl;
  }  
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)

using namespace std;

static const int N = 100;
static const int white = 0;
static const int gray = 1;
static const int black = 2;

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

void dfs_visit(int u) {
  color[u] = gray;
  d[u] = ++tt;
  REP(v, n) {
    if ( M[u][v] == 0) continue;
    if ( color[v] == white ) {
      dfs_visit(v);
    }
  }
  color[u] = black;
  f[u] = ++tt;
}

void dfs() {
  REP(u, n) color[u] = white;
  tt = 0;

  REP(u, n) {
    if ( color[u] == white ) dfs_visit(u);
  }
  REP(u, n) {
    cout << u + 1 << " " << d[u] << " " << f[u] << endl;
  }
}

int main() {
  int u, v, k;

  cin >> n;
  REP(i, n) {
    REP(j, n) {
      M[i][j] = 0;
    }
  }

  REP(i, n) {
    cin >> u >> k;
    u--;
    REP(j, k) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();

  return 0;
}