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 <list>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <algorithm>
#include <cmath>
#include <string>
using namespace std;
typedef long long lli;
typedef vector<lli> vll;
typedef vector<bool> vbl;
typedef vector<vector<lli> > mat;
typedef vector<vector<bool> > matb;
typedef vector<string> vst;
typedef pair<lli,lli> pll;
typedef pair<double,double> pdd;

lli n;
mat g;
vll d;
vll f;
vbl vis;

lli u,k,v;
lli t = 0;

lli dfs(lli x,lli t){
    d[x] = t;
    vis[x] = true;
    for(lli i = 0;i < g[x].size();i++){
        if(!vis[g[x][i]]) t = dfs(g[x][i],t+1);
    }
    return f[x] = t + 1;
}

int main(){
    cin >> n;
    g = mat(n+1);
    d = vll(n+1);
    f = vll(n+1);
    vis = vbl(n+1);
    for(lli i = 0;i < n;i++){
        cin >> u >> k;
        for(lli i = 0;i < k;i++){
            cin >> v;
            g[u].push_back(v);
        }
    }
    for(lli i = 1;i <= n;i++){
        if(!vis[i]) t = dfs(i,t+1);
    }
    for(lli i = 1;i <= n;i++){
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: #include<iostream>
#include<stack>
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];
int color[N], d[N], f[N], tt;
int nt[N];


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

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

	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() {
	for (int i = 0; i < n; i++) {
		color[i] = WHITE;
	}
	tt = 0;

	for (int u = 0; u < n; u++) {
		if (color[u] == WHITE) dfs_visit(u);
	}
	for (int i = 0; i < n; i++) {
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
	}
}


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

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

int main(){
  vector<int> G[100];
  stack<int> q;
  vector<int> d(100,200000000),f(100,200000000);
  int n,u,k,v,time=0;
  bool flg;
  
  cin >> n;
  //G.push_back(new vector<int>(,10));
  for (int i=0;i<n;i++){
    cin >> u>> k;
    for (int j=0;j<k;j++){
      cin >> v;
      G[u-1].push_back(v-1);
    }
  }

  q.push(0);
  d[0]=++time;
  while (!q.empty()){
    u=q.top();
    for (int i=0;i<G[u].size();i++){
      v=G[u][i];
      if (d[v]>time){
	q.push(v);
	d[v]=++time;
	flg=true;
	break;
      }
    }
    if (!flg){
      q.pop();
      f[u]=++time;
    }else{
      flg=false;
    }
  }
  for (int i=0;i<n;i++)
    cout << i+1 <<" "<< d[i]<<" "<<f[i]<<endl;
  
  return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<queue>
#include<map>
#include<set>
#include<vector>
#include<stack>
#include<list>

typedef long long ll;

using namespace std;

int a[110][110];
int d[110];
int f[110];
int vis[110];
int n;
int time;

void dfs_visit(int u){
	vis[u] = 1;
	d[u] = ++time;
	for(int i = 1 ; i<=n ; i++){
		//cout<<u<<i<<" "<<a[u][i]<<endl; 
		if(a[u][i] == 0){
			continue;
		}
	
		if(vis[i] == 0){
			dfs_visit(i);
		}
	}
	f[u] = ++time;
}

void dfs(){
	time = 0;
	for(int i = 1 ; i<=n ; i++){
		if(vis[i] == 0)
			dfs_visit(i);
	}
}

int main(){
	ios::sync_with_stdio(false);
	cin>>n;
	
	memset(a,0,sizeof(a));
	
	for(int c = 1; c<=n ; c++){
		int t;
		int i;
		cin>>i>>t;
		while(t--){
			int j;
			cin>>j;
			a[i][j] = 1;
		}
	}
	
	
	memset(d,0,sizeof(d));
	memset(vis,0,sizeof(vis));
	memset(f,0,sizeof(f));
	dfs();
	
	for(int i = 1 ; i<=n ; i++){
		printf("%d %d %d\n",i,d[i],f[i]);
	}
	return 0;
}

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

int G[105][105]={};
int d[105]={},f[105]={};
int N,T=0;

void Gprint(int n){
    cout<<"\\|";
    for(int i=0; i<n; i++)cout<<i+1;
    cout<<endl;
    for(int i=0; i<n+2; i++)cout<<"-";
    cout<<endl;
    for(int i=0; i<n; i++){
        cout<<i+1<<"|";
        for(int j=0; j<n; j++){
            cout<<G[i][j];
        }
        cout<<endl;
    }
}

void dfs(int n){
    if(d[n])return;
    d[n]=++T;
    for(int i=n+1; i<N; i++){
        if(G[n][i])dfs(i);
    }
    f[n]=++T;
}

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

    cin>>N;
    for(int i=0; i<N; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            cin>>v;
            G[u-1][v-1]=1;
        }
    }

//    Gprint(N);

    dfs(0);

    for(int i=0; i<N; i++){
        cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
    }
}