Go: package main

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

/***************************************************************
stackによる深さ優先探索を実装する。
***************************************************************/

const (
	N     = 100
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var (
	n            int
	Adj          [N][N]int
	statusColor  [N]int
	discoverTime [N]int
	finishTime   [N]int
	clock        int
	nt           [N]int
)

/***************************************************************
Stackの定義:
- field
	container: ノードの格納されたスライス
	sp: スタックポインタ
- method
	size(): スタックに積まれているノードの個数を返す
	top(): スタックの一番上に積まれているノードを返す
	isEmpty(): スタックが空かどうかを返す
	pop(): スタックの要素をポップし削除する
	push(): スタックに要素を積む
***************************************************************/

type Stack struct {
	container []int
	sp        int
}

func (s *Stack) size() int {
	return len(s.container)
}

func (s *Stack) top() int {
	return s.container[s.sp]
}

func (s *Stack) isEmpty() bool {
	return s.sp == 0
}

func (s *Stack) pop() int {
	_pop := func() {
		s.container = s.container[:len(s.container)-1]
	}
	defer _pop()
	if s.isEmpty() {
		panic("There is no elements in stack!")
	}
	s.sp--
	return s.container[s.sp]
}

func (s *Stack) push(n int) {
	s.sp++
	s.container[s.sp] = n
}

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

func _DFS(target int) {
	for i := 0; i < n; i++ {
		nt[i] = 0
	}
	stack := new(Stack)
	stack.container = make([]int, N)
	stack.push(target)
	statusColor[target] = GRAY
	clock++
	discoverTime[target] = clock
	for !stack.isEmpty() {
		u := stack.top()
		v := next(u)
		if v != -1 {
			if statusColor[v] == WHITE {
				statusColor[v] = GRAY
				clock++
				discoverTime[v] = clock
				stack.push(v)
			}
		} else {
			stack.pop()
			statusColor[u] = BLACK
			clock++
			finishTime[u] = clock
		}
	}
}

func DFS() {
	for i := 0; i < n; i++ {
		statusColor[i] = WHITE
		nt[i] = 0
	}
	clock = 0
	for i := 0; i < n; i++ {
		if statusColor[i] == WHITE {
			_DFS(i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, discoverTime[i], finishTime[i])
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			Adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ := strconv.Atoi(scanner.Text())
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		u--
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ := strconv.Atoi(scanner.Text())
			v--
			Adj[u][v] = 1
		}
	}

	DFS()
}

C++: 

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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;
        nt[i] = 0;
    }
    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>

using namespace std;

const int MAX = 100;

void search(bool graph[MAX][MAX], int find[], int done[], int n, int u,int& count) {
	count++;
	find[u] = count;
	for (int i = 0; i < n; i++) {
		if (graph[u][i] && find[i] == 0) {
			search(graph, find, done, n, i, count);
		}
	}
	count++;
	done[u] = count;
}

int main() {
	bool check[MAX] = { false };
	int find[MAX] = { 0 };
	int done[MAX] = { 0 };
	bool graph[MAX][MAX] = { {false} };
	int N;

	cin >> N;
	for (int i = 0; i < N; i++) {
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			int temp;
			cin >> temp;
			graph[u - 1][temp - 1] = true;
		}
	}

	int count = 0;
	for (int i = 0; i < N; i++) {
		if (find[i] == 0) {
			search(graph, find, done, N, 0, count);
		}
	}

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

	return 0;
}

C++: #include <stdio.h>
#define N 100
#define WHITE 0
#define GRAY  1
#define BLACK 2

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

void dfs_visit(int u)
{
    int v;
    color[u]=GRAY;
    d[u]=++tt;
    for(v=0;v<n;v++)
    {
        if(M[u][v]==0) continue;
        if(color[v]==WHITE)
            dfs_visit(v);
    }
    color[u]=BLACK;
    f[u]=++tt;
}

void dfs()
{
    int u;
    for(u=0;u<n;u++)
        color[u]=WHITE;
    tt=0;
    for(u=0;u<n;u++)
        if(color[u]==WHITE)
            dfs_visit(u);
    for(u=0;u<n;u++)
        printf("%d %d %d\n",u+1,d[u],f[u]);
}

int main()
{
    int u,v,k,i,j;
    scanf("%d",&n);
    for(i=0;i<n;i++)
        for(j=0;j<n;j++)
            M[i][j]=0;
    for(i=0;i<n;i++)
    {
        scanf("%d %d",&u,&k);
        u--;
        for(j=0;j<k;j++)
        {
            scanf("%d",&v);
            v--;
            M[u][v]=1;
        }
    }
    dfs();
    return 0;
}

C++: /*
 * ALDS1_11_B.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<iostream>
#include<vector>

using namespace std;

int d[101];
int f[101];
int nowTime;

void dfsRec(vector<int>* a, int n, int v) {
	if(d[v] > 0) return;
	nowTime++;
	d[v] = nowTime;
	for(int &x:a[v]) {
		dfsRec(a, n, x);
	}
	nowTime++;
	f[v] = nowTime;
}

int main() {
	int n;
	vector<int> adj[101];

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

	for(int i=1; i<=n; i++) {
		if(d[i] ==0) dfsRec(adj, n, i);
	}

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

C++: #include<iostream>
using namespace std;
int size[101],graph[101][100],cnt,times[101],timee[101];

void dfs(int x){
  if(times[x]==0){
    times[x]=++cnt;
    for(int i=0;i<size[x];++i){
      if(times[graph[x][i]]==0) dfs(graph[x][i]);
    }
    timee[x]=++cnt;
  }
}

int main(){
  int n,u,k,v; cin>>n;
  for(int i=0;i<n;++i){
    cin>>u>>k;
    size[u]=k;
    for(int j=0;j<k;++j){
      cin>>v;
      graph[u][j]=v;
    }
  }
  for(int i=1;i<=n;++i) dfs(i);
  for(int i=1;i<=n;++i) cout<<i<<" "<<times[i]<<" "<<timee[i]<<endl;
  return 0;
}