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 <string>
#include <stdio.h>
using namespace std;

int d[100];
int f[100];
int map[100][100];
int tim;
int n;
void visit(int);

int main(){
	tim=0;
	int i,j,k,u,v;
	for(i=0;i<100;i++) d[i]=-1;
	for(i=0;i<100;i++) f[i]=-1;
	cin >> n;
	for(i=0;i<n;i++){
		for(j=0;j<n;j++){
			map[i][j]=0;
		}
	}
	for(i=0;i<n;i++){
		cin>>u>>k;
		for(j=0;j<k;j++){
			cin>>v;
			map[u-1][v-1]=1;
		}
	}
	visit(0);
	// ??¨???????????????????????????????????°?¨????????????¨??????
	for(i=0;i<n;i++){
		cout<< i+1 << " "<<d[i]<< " "<<f[i];
		cout<<endl;
	}
	return 0;
}

void visit(int k){
	int i;
	d[k]=++tim;
	for(i=0;i<n && f[k]==-1;i++){
		if(map[k][i]==1&&d[i]==-1){
			visit(i);
		}
	}
	f[k]=++tim;
}

C++: #include<bits/stdc++.h>

using namespace std;
using ll = long long;


int n;
vector<vector<int>> hen;
vector<int> in, out;
vector<bool> seen;

void dfs(int cur, int& tim)
{
    tim++;
    in[cur] = tim;
    seen[cur] = true;
    for(auto i : hen[cur])
    {
        if(seen[i])continue;
        dfs(i, tim);
    }
    tim++;
    out[cur] = tim;
}


int main()
{
    cin >> n;
    hen.resize(n);
    in.resize(n);
    out.resize(n);
    seen.resize(n);
    for(int i = 0; i < n; i++){
        int u,k;cin >> u >> k; u--;
        for(int j = 0; j < k; j++){
            int v; cin >> v; v--;
            hen[u].push_back(v);
        }
        sort(hen[u].begin(), hen[u].end());
    }

    int t = 0;
    for(int i = 0; i < n; i++){
        if(!seen[i])dfs(i,t);
    }

    for(int i = 0; i < n; i++){
        cout << i + 1 << " " << in[i] << " " << out[i] << endl;
    }
}

C++: #include <iostream>

using namespace std;

#define MAX 100

int n,Time;
int G[MAX][MAX],d[MAX],f[MAX];
bool used[MAX];

void dfs(int v){
  d[v] = Time++;
  used[v] = true;

  for(int i = 0 ; i < n ; i++){
    if(!used[i] && G[v][i]){
      dfs(i);
    }
  }

  f[v] = Time++;
}

int main(){
  cin >> n;

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

  Time = 1;
  for(int i = 0 ; i < n ; i++){
    if(!used[i]){
      dfs(i);
    }
  }

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

  return 0;
}

C++: #include<queue>
#include<stack>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
 
int n, dd[100], f[100], tmap[100][100];
int color[100], t = 1;
stack<int> S;
 
int a(){
    int d = S.top();
    dd[d] = t;
    t++;
    color[d] = 1;

    for (int i = 1; i <= n; i++){
        if (color[i] == 0 && tmap[d][i] == 1){
            S.push(i);
            a();
        }
    }

    f[d] = t;
    t++;
    return 0;
}
 
 
int main(){
    cin >> n;
    for (int i = 0; i < 100; i++){
        dd[i] = f[i] = color[i] = 0;
        for (int j = 0; j < 100; j++){
            tmap[i][j] = 0;
        }
    }
 
    int u, k, v;
 
    for (int i = 0; i < n; i++){
        cin >> u >> k;
        for (int j = 0; j < k; j++){
            cin >> v;
            tmap[u][v] = 1;
        }
    }
    for(int i=1;i<=n;i++){
        if(color[i] == 0){
             S.push(i);
             a();
         }
    }
    for (int i = 1; i <= n; i++){
        cout << i << " " << dd[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
#include <map>
#include <stack>
#include <algorithm>
using namespace std;
#define MAX 100000

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>
#include<stack>
#include<queue>
using namespace std;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

struct Node{
	int color, d, f;
	queue<int> Q;
};

int main(){
	int n;
	cin >> n;
	Node node[n + 1];
	stack<int> move;
	for(int i = 1; i <= n; i++){
		int u, k, v;
		cin >> u >> k;
		node[u].color = WHITE;
		while(k--){
			cin >> v;
			node[u].Q.push(v);
		}
	}

	move.push(1);
	int tt = 1, p, next;
	node[1].color = GRAY;
	node[1].d = tt;
	tt++;

	while(!move.empty()){
		p = move.top();
		if(node[p].Q.empty()){
			node[p].color = BLACK;
			node[p].f = tt;
			move.pop();
			tt++;
		} else {
			next = node[p].Q.front();
			if(node[next].color == WHITE){
				move.push(next);
				node[next].color == GRAY;
				node[next].d = tt;
				tt++;
			} else {
				node[p].Q.pop();
			}
		}
	}

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