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<cstdio>
using namespace std;
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define N 100
int M[N][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(i = 0;j<k;j++)
      {
        scanf("%d",&v);
        v--;
        M[u][v] =1;
      }
  }
  dfs();
  return  0 ;
}

C++: #include<bits/stdc++.h>
#define N 105
using namespace std;
int n,u,k,v,e[N][N],cnt;
int ans1[N],ans2[N];
bool used[N];
 
void dfs(int x){
  if(used[x])return;
  used[x]=true;
  ans1[x]=cnt++;
  for(int i=0;i<n;i++)
    if(e[x][i])dfs(i);
  ans2[x]=cnt++;
}
 
int main(){
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    for(int j=0;j<k;j++){
      cin>>v;
      e[u-1][v-1]=1;
    }
  }
  cnt=1;
  for(int i=0;i<n;i++)
    if(!used[i])dfs(i);
  
  for(int i=0;i<n;i++)
    cout<<i+1<<' '<<ans1[i]<<' '<<ans2[i]<<endl;

  return 0;
}

C++: #include<iostream>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 1

int n, M[N][N];
int color[N], s[N], f[N], ts; 

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

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

int main() {
    int u, k, tmp;
    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;
        for (int j=0; j<k; j++) {
            cin >> tmp;
            M[u-1][tmp-1] = 1;
        }
    }
    dfs();
    return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_A
// Graph I - Depth First Search

#define SUBMIT

#include <utility>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <vector>
#include <limits>
#include <numeric>
#include <functional>
#include <set>
#include <cmath>
#include <cstring>
#include <climits>
#include <memory>

using namespace std;
using ui64 = unsigned long long;
using i64 = long long;

const ui64 MAX_N = 100;

enum class color_type {
    white,
    gray,
    black
};

int adj[MAX_N][MAX_N];
color_type color[MAX_N];
int find_time[MAX_N];
int complete_time[MAX_N];
int n;
int curr_time;

void dfs(int u) {
    curr_time++;
    color[u] = color_type::gray;
    find_time[u] = curr_time;

    // search adj nodes
    for (int v = 0; v < n; ++v) {
        if (adj[u][v] != 0 && color[v] == color_type::white) dfs(v);
    }
    curr_time++;
    color[u] = color_type::black;
    complete_time[u] = curr_time;
}

void run_dfs() {
    for (int v = 0; v < n; ++v) {
        color[v] = color_type::white;
        find_time[v] = 0;
        complete_time[v] = 0;
    }

    curr_time = 0;
    for (int v = 0; v < n; ++v) {
        if (color[v] == color_type::white) dfs(v);
    }
}

int main() {
    memset(adj, 0, sizeof(adj));
    cin >> n;

    int u, degree;
    for (int i = 0; i < n; ++i) {
        cin >> u >> degree;
        u--; // 0-origin

        int v;
        for (int j = 0; j < degree; ++j) {
            cin >> v;
            v--; //0-origin
            adj[u][v] = 1;
        }
    }

    run_dfs();
    for (int i = 0; i < n; ++i) cout << i + 1 << " " << find_time[i] << " " << complete_time[i] << endl;
    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, tt;
int M[N][N], color[N], d[N], f[N], 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 {
		   color[u] = BLACK;
		   S.pop();
		   f[u] = ++tt;
		}
	} 
}


void dfs() {
	for(int i = 0; i < n; i++) {
	     color[i] = WHITE;
	}
	tt = 0;
		
	//for(int u = 0; u < n; u++) {
	//	if(color[u]) dfs_visit(u);
	//}
	dfs_visit(0);
	
	for(int i = 0; i < n; i++) {
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;	
	}
}

int main() {
	int k , u, 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 i = 0; i < k; i++) {
	        cin >> v;
	        v--;
		   M[u][v] = 1; 
     	}
	} 
	
	dfs();
	
	return 0;
}