Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type vertexId int

type vertex struct {
	id vertexId
	firstVisitAt int
	finishVisitAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		firstVisitAt: 0,
		finishVisitAt: 0,
		adjs: adjs,
	}
}

func (v *vertex) doesAllAdjsVisited(vertices []vertex) bool {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return false
		}
	}
	return true
}

func (v *vertex) isFirstVisit() bool {
	return v.firstVisitAt == 0
}

func (v *vertex) isVisited() bool {
	return v.firstVisitAt > 0
}

func (v *vertex) nextVertex(vertices []vertex) (vertexId, error) {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return vId, nil
		}
	}
	return vertexId(-1), fmt.Errorf("illegal")
}

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	timestamp = timestamp + 1
	currentVertex := &vertices[currentId-1]
	if currentVertex.isFirstVisit() {
		currentVertex.firstVisitAt = timestamp
	}
	for !currentVertex.doesAllAdjsVisited(vertices) {
		nextVertexId, _ := currentVertex.nextVertex(vertices)
		timestamp = dfs(nextVertexId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	dfs(vertexId(1), 0, vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", vertices[i].id, vertices[i].firstVisitAt, vertices[i].finishVisitAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

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

int timex = 0;

int n;

string *color = new string[n];

int *d = new int[n];

int *f = new int[n];

int c[100][100];

void dfs(int u){
  color[u] = "glay";
  d[u] = ++timex;

  for(int v = 0; v < n; v++){
    if(c[u][v] == 1 && color[v] == "white"){
      dfs(v);
    }
  }

color[u] = "black";
f[u] = ++timex;

}

int main(){

  int n;

  cin >> n;

  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      c[i][j] = 0;
    }
  }

  for(int i = 0; i < n; i++){
    int x;
    cin >> x;
    int k;
    cin >> k;
    for(int j = 0; j < k; j++){
      int v;
      cin >> v;
      c[i][v - 1] = 1;
    }
  }

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

  dfs(0);

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




  return 0;
}

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

using namespace std;

int t;
int N;
int d[110], f[110];
vector<vector<int> > adj(110);
void dfs(int cur){
    d[cur] = t;
    t += 1;
    //cerr << "visiting " << cur << " " << t << endl;
    for(int i = 0; i < adj[cur].size(); ++i){
        int dst = adj[cur][i];
        if(d[dst] == 0){
            dfs(dst);
        }
    }
    f[cur] = t;
    t++;
}

int main(){
    cin >> N;
    t = 1;
    int u, k;
    for(int i = 0; i < N; ++i){
        d[i] = 0;
        f[i] = 0;
    }
    for(int i = 0; i < N; ++i){
        cin >> u >> k;
        for(int j = 0; j < k; j++){
            int v;
            cin >> v;
            adj[u].push_back(v);
        }
        sort(adj[u].begin(), adj[u].end());
    }
    for(int i = 1; i < N+1; ++i){
        if(d[i] == 0) dfs(i);
    }
    
    for(int i = 1; i < N+1; ++i){
        cout << 1 << " " << d[i] << " " << f[i] << endl;
    }
}

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

int a[100][100];
int n,p,q,r;
int T[100],F[100];
int Time = 0;
void dfs(int cur) {
	T[cur] = Time;
	Time += 1;
	for (int dst=0; dst < n; ++dst) {
		if(a[cur][dst] == 1 && T[dst] == -1) {
			dfs(dst);
		}
	}
	F[cur] = Time;
	Time += 1;
}

int main() {
	cin >> n;
	for (int i=0; i<n; ++i) {
		cin >> p >> q;
		T[i] = -1;
		for (int j=0; j<q; ++j) {
			cin >> r;
			a[p-1][r-1] = 1;
		}
	}
	dfs(0);
	for (int i=0; i<n-1; ++i) {
		cout << i+1 << " " << T[i]+1 << " " << F[i]+1 << endl;
	}
	cout << n << " " << T[n-1]+1 << " " << F[n-1]+1 << endl;
}

C++: #include <iostream>
#include <vector>
using namespace std;
vector<int> E[101];
bool visited[101];
int in[101];
int out[101];
int count=0;
int nv(int n)
{
	int i=1;
	for(i=1;i<=n;i++)
	{
		if ( visited[i]==false )
			return i;
	}
	if (i>n) return 0;
}

void bfs(int n)
{
	visited[n]=true;
	in[n]=++count;
	for(vector<int>::iterator it=E[n].begin();it!=E[n].end();++it)
	{
		int now=*it;
		if(visited[now]==false)
			bfs(now);
	}
	out[n]=++count;
}

int main()
{
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		int e,n0;
		cin>>e>>n0;
		for(int j=0;j<n0;j++)
		{
			int t;
			cin>>t;
			E[e].push_back(t);
		}
		visited[i]=false;
		in[i]=out[i]=0;
	}

	int now=nv(n);
	while(now!=0)
	{
		bfs(now);
		now=nv(n);
	}


/*	for(int i=1;i<=n;i++)
	{
		for(vector<int>::iterator it=E[i].begin();it!=E[i].end();++it)
			cout<<*it<<" ";
		cout<<endl;
	}
*/
	for(int i=1;i<=n;i++)
		cout<<i<<" "<<in[i]<<" "<<out[i]<<endl;
	return 0;

	

}

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

int n, t;
int v[100][100];
int d[100], f[100], r[100];

void stamp(int id) {
	if (d[id - 1] == 0) {
		d[id - 1] = t;
		t++;
		int i = 0;
		while (v[id - 1][i] == 0)
			i++;
		if (i < n && d[i] == 0)
			stamp(i + 1);
		else
			stamp(id);
	}
	else if (f[id - 1] == 0) {
		int i;
		for(i = 0; i < n; i++)
			if (v[id - 1][i] == 1 && d[i] == 0)
				stamp(i + 1);
		if (i > n - 1 && f[id - 1] == 0) {
			f[id - 1] = t;
			t++;
			int j1, ct = 0;
			for (int j = n - 1; j > -1; j--)
				if (v[j][id - 1] == 1 && f[j] == 0 && d[j] != 0) {
					j1 = j;
					ct++;
				}
			if (ct == 1)
				stamp(j1 + 1);
			else {
				for (int j = 1; j < n; j++)
					if (d[j] == d[id - 1] - 1)
						stamp(j + 1);
			}

			int k = 0;
			while (d[k] != 0)
				k++;
			if (k < n)
				stamp(k + 1);
		}
	}
	else	
		return;
}

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		d[i] = 0;
		f[i] = 0;
	}

	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			v[i][j] = 0;

	for (int i = 0; i < n; i++) {
		int u, k, s;

		cin >> u >> k;

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

	t = 1;
	stamp(1);

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

	return 0;
}