Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #include<iostream>
#include<vector>
#define SIZE 1000000
using namespace std;

struct Stack{
  int line[SIZE];
  int top;
  void init(){
    top = 0;
  }
  bool empty(){
    return top==0;
  }
  void push(int x){
    line[top]=x;
    top ++;
  }
  int pop(){
    if(empty()) return -1;
    top--;
    return line[top];
  }
};
struct Node
{
  vector<int> toList;
  int dt;
  int ft;
};

Stack stack; 
int t; //time

void init(vector<Node>& nodes)
{
  t=0;
  stack.init();
  stack.push(0);
  for(int i=0;i<nodes.size();i++){
    nodes[i].ft=-1;
    nodes[i].dt=-1;
  }
}
void print(vector<Node> nodes)
{
  int n=nodes.size();
  for(int i=0;i<n;i++){
    cout<<i+1<<" "<<nodes[i].ft<<" "<<nodes[i].dt<<endl;
  }
}
void dfs(vector<Node>& nodes)
{ 
  int idx=stack.pop();
  //cout<<idx+1<<":";
  if(idx>=0){
    if(nodes[idx].ft<0){
      //cout<<" find";
      t++;
      nodes[idx].ft=t;
    }
    if(nodes[idx].toList.size()<=0){
      //cout<<" toList.size==0"<<endl;
      t++;
      nodes[idx].dt=t;
      dfs(nodes);
    }
    int count=0;
    for(int i=0;i<nodes[idx].toList.size();i++){
      if(nodes[nodes[idx].toList[i]].dt<0){
	//cout<<" jumpto "<<i+1<<endl;
	count++;
	stack.push(idx);
	stack.push(nodes[idx].toList[i]);
	dfs(nodes);
      }
    }
    if(count==0 && nodes[idx].dt<0){
      //cout<<" finish"<<endl;
      t++;
      nodes[idx].dt=t;
      dfs(nodes);
    }
  }else{
    //cout<<"finish dfs"<<endl;
  }
}

int main()
{
  int n,u,k;
  cin>>n;
  vector<Node> nodes(n);
  for(int i=0;i<n;i++){
    cin>>u>>k;
    nodes[i].toList.resize(0);
    for(int j=0;j<k;j++){
      int tmp;
      cin>>tmp;
      nodes[i].toList.push_back(tmp-1);
    }
  }
  init(nodes);
  //print(nodes);

  dfs(nodes);
  print(nodes);
  return 0;
}

C++: def main():
    n = input()
    A = []
    s = []
    B = [[0,0] for i in xrange(n)]
    for i in xrange(n):
        A.append(map(int,raw_input().split()))

    color = [-1]*n
    d = [0]*n
    f = [0]*n
    
    dfs(0,0,color,d,f,A,n)

    for i in xrange(n):
        print i+1, d[i], f[i]


def dfs(u,t,color,d,f,A,n):
    t += 1
    color[u] = 0
    d[u] = t
    for i in A[u][2:]:
        if (color[i-1] == -1):
            t = dfs(i-1,t,color,d,f,A,n)
    color[u] = 1
    t += 1
    f[u] = t
    return t

if __name__ == '__main__':
    main()

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

void search(int i,int *table, int n, int *d, int *f, int *cnt){
	
	++(*cnt);
	d[i] = *cnt;
	
	for(int j=0;j<n;++j){
		if(table[i*n+j]){
			for(int k=0;k<n;++k){
				table[k*n+j] = 0;
			}
			search(j,table,n,d,f,cnt);
		}
	}
	
	++(*cnt);
	f[i] = *cnt;
}

int main() {
	int n,*table,*d,*f, cnt;
	
	cin>>n;
	table = new int[n*n];
	d = new int[n];
	f = new int[n];
	
	for(int i=0;i<n;++i){
		int u,k,v;
		cin>>u>>k;
		for(int j=0;j<k;++j){
			cin>>v;
			table[(u-1)*n+v-1]=1;
		}
	}
	cnt = 0;
	search(0,table,n,d,f,&cnt);
	
	for(int i=0;i<n;++i){
		cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
	}
	
	
	return 0;
}

C++: #include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i < (n+1); ++i)
using namespace std;
using ll = long long;
const int INF = +100100100;
// typedef pair<int,int> P;

vector<vector<int>> DF(150, vector<int>(150,0));
vector<int> color(150,0);
int tt=0;
vector<int> F(150), D(150);
int n;
# define WHITE 0
# define GRAY 1
# define BLACK 2




void dfs_visit(int u){
    F[u] = ++tt;
    color[u]=GRAY;
    rep(i,n){
        if(DF[u][i]==1 && color[i]==WHITE){
            dfs_visit(i);
        }
    }
    color[u]==BLACK;
    D[u]=++tt;
}

void dfs(){
    rep(u,n){
        if(color[u]==WHITE)dfs_visit(u);
    }
}

int main(){
    cin >> n;
    vector<list<int>>  L(n);
    rep(i,n){
        int u, e;
        cin >> u>>e;
        rep(j,e){
            int v;cin>>v;--v;
            L[i].push_back(v);
        }
    }
    rep(i,n){
        rep(j,n){
            list<int>::iterator it = find(L[i].begin(),L[i].end(),j);
            if(it!=L[i].end()){
                DF[i][j]=1;
                L[i].erase(it);
            }
        }
    }
    dfs();
    rep(i,n){
        printf("%d %d %d\n",i+1,F[i],D[i]);
    }
    return 0;
}

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

#define WHITE 0
#define GRAY 1
#define BLACK 2

int d[101], f[101];
int color[101] = { 0 };
int M[101][101] = { 0 };

int times;

int cur;

stack<int> s;

int search_node(int n) {
    for (int node = 1; node <= n; ++node) {
        if (M[cur][node] == 1 && color[node] == WHITE) {
            return node;
        }
    }
    return -1;      // 見つからなかった場合
}

void visit_node(int target) {
    times += 1;
    s.push(target);
    cur = s.top();
    d[cur] = times;
    color[cur] = GRAY;
}

void reversal_node() {
    // ノードを戻っていく終了時刻を記入する処理+スタック削除
    times += 1;
    s.pop();
    f[cur] = times;
    color[cur] = BLACK;
    if (s.size() != 0) {
        cur = s.top();
    } else {
        cur = 0;
    }
}

bool black_judge(int n) {        // すべて探索済みか判定，初期化
    for (int node = 1; node <= n; ++node) {
        if (color[node] != BLACK) {
            s.push(node);
            cur = node;
            color[node] = GRAY;
            d[node] = times;
            return false;
        }
    }
    return true;
}

int main() {
    int n;
    cin >> n;
    int u, k;
    int ver;
    times = 0;
    for (int i = 1; i <= n; ++i) {
        cin >> u >> k;
        for (int j = 1; j <= k; ++j) {
            cin >> ver;
            M[i][ver] = 1;           // 隣接行列が得られる
        }
    }

    while (true) {
        times += 1;
        if (black_judge(n)) {
            break;                  // すべて探索済みなら完了
        }
        while (s.size() != 0) {
            int target;
            target = search_node(n);
            if (target == -1) {
                reversal_node();
            } else {
                visit_node(target);
            }
        }
    }
    
    for (int i = 1; i <= n; ++i) {
        cout << i << " " << d[i] << " " << f[i] << endl;
    }

    return 0;
}