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 <string>
#include <vector>
using namespace std;
typedef long long ll;
const int INF = 1<<30; 
const int MOD = 1e9 + 7;
const int MAX_N = 150;
int G[MAX_N][MAX_N], found[MAX_N], finished[MAX_N];
int Time, N;
void dfs(int u)
{
    Time++;
    found[u] = Time;
    for(int nextV = 1; nextV <= N; nextV++)
    {
        if(found[nextV] || G[u][nextV] == 0) continue;
        dfs(nextV);
    }
    Time++;
    finished[u] = Time;
}
void init()
{
    Time = 0;
    for(int i = 0; i <= N; i++)
    {
        found[i] = 0;
        finished[i] = 0;
    }
    for(int i = 0; i <= N; i++) for(int j = 0; j <= N; j++) G[i][j] = 0;
}
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> N;
    init();
    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[u][v] = 1;
        }
    }
    int u = 1;
    while(u <= N)
    {
        if(found[u] == 0) dfs(u);
        u++;
    }
    for(int v = 1; v <= N; v++)
    {
        cout << v << " " << found[v] << " " << finished[v] << endl;
    }
    return 0;
}

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

void solve(){
  int n; cin >> n;
  vector<vector<int> > v(n + 1, vector<int>(n + 1, 0));
  for(int i = 0; i < n; i++){
    int u, k; cin >> u >> k;
    for(int j = 0; j < k; j++){
      int x; cin >> x;
      v[u][x] = 1;
    }
  }
  vector<int> d(n + 1), f(n + 1), c(n + 1, 0);
  stack<int> s;
  int t = 0;
  for(int j = 1; j <= n; j++){
    if(c[j] == 0){
      s.push(j);
      d[j] = ++t;
      c[j] = 1;
      while(s.size() != 0){
        t++;
        int x = s.top();
        int i;
        for(i = 1; i <= n; i++){
          if(v[x][i] == 1 && c[i] == 0){
            d[i] = t;
            c[i] = 1;
            s.push(i);
            break;
          }
        }
        if(i == n + 1){
          f[x] = t;
          s.pop();
        }
      }
    }
  }
  for(int i = 1; i <= n; i++){
    cout << i << " " << d[i] << " " << f[i] << endl;
  }
  return;
}

int main(){
  solve();
  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],sta[N],fin[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; //下に辺があれば返す
  }
  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;
  sta[r]= ++tt;

  while(!s.empty()) //空じゃない間
  {
    int u=s.top();
    int v= next(u);
    if(v != -1)
    {
      if(color[v]==white)
      {
        color[v]=gray;
        sta[v]= ++tt;
        s.push(v);
      }
    }
    else //v=-1
    {
      s.pop();
      color[u]=black;
      fin[u]= ++tt;
    }
  }
}

void dfs()
{
  //初期化
  for(int i=0;i<n;i++)
  {
    color[i]=white;
    nt[i]=0;
  }
  tt=0;

  //未訪問のuを始点としてdfsする
  for(int u=0;u<n;u++)
  {
    if(color[u]==white) dfs_visit(u);
  }
  for(int i=0;i<n;i++)
  {
    cout<<i+1<<" "<<sta[i]<<" "<<fin[i]<<endl;
  }
}

int main()
{
  //入力
  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; //辺があれば1と定義される
    }
  }

  dfs();
}