Go: package main

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

const MAX = 101

var f [MAX]int
var d [MAX]int
var list [][]int
var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(u, cnt int) int {
	if d[u] != 0 {
		return cnt
	}

	cnt++
	d[u] = cnt
	for _, next := range list[u] {
		cnt = dfs(next, cnt)
	}
	cnt++
	f[u] = cnt
	return cnt
}

func main() {
	n := scanInt()
	list = make([][]int, n+1)
	for i := 1; i <= n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			n := scanInt()
			list[u] = append(list[u], n)
		}
	}

	cnt := 0
	for i := 1; i <= n; i++ {
		cnt = dfs(i, cnt)
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, d[i])
		fmt.Fprint(w, " ")
		fmt.Fprint(w, f[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

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,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<algorithm>
#include<cstdio>
#include<cstring>
#include<stack>
#include<string>
#define NIL -1

using namespace std;

const int white=0;
const int gray=1;
const int black=2;
const int maxn=1110;
int G[maxn][maxn];
int color[maxn];
int ne[maxn],d[maxn],f[maxn];
int n,tt; 

int next(int u)
{
	for(int v=ne[u];v<n;v++){
		ne[u]=v+1;
		if(G[u][v])return v;
	}
	return NIL;
}

void dfs(int r)
{
	if(r>=n||color[r]!=white)return;
	stack<int> st;
	memset(ne,0,sizeof(ne));
	st.push(r);
	color[r]=gray;
	d[r]=++tt;
	while(!st.empty()){
		int u=st.top();
		int v=next(u);
		if(v!=NIL){
			if(color[v]==white){
				color[v]=gray;
				d[v]=++tt;
				st.push(v);
			}
		}else{
			color[u]=black;
			st.pop();
			f[u]=++tt;
		}
	}
	while(color[r+1]!=white)r++;
	dfs(r+1);
}

int main()
{
	memset(color,white,sizeof(white));
	memset(G,0,sizeof(G));
	memset(f,0,sizeof(f));
	memset(d,0,sizeof(d));
	int u,k,v;
	cin>>n;
	//邻接矩阵存图 
	for(int i=0;i<n;i++){
		cin>>u>>k;
		u--;
		for(int j=0;j<k;j++){
			cin>>v;
			v--;
			G[u][v]=1;
		}
	}
	tt=0;
	dfs(0);
	for(int i=0;i<n;i++){
		cout<<i+1<<' '<<d[i]<<' '<<f[i]<<endl;
	}
	return 0;
}

C++: #include <cstdio>
#include <stack>
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define MAX 100
using namespace std;

int A[MAX][MAX] = {0};
int color[MAX] = {0};
int f[MAX] = {0};
int d[MAX] = {0};
int time = 0;
int n;
stack<int> S;

int next(int u)
{
	for(int i=0; i<n; i++)
	{
		if(A[u][i])
		{
			if(color[i] == WHITE)
				return i;
		}
	}
	return -1;
}

void dfs(int u)
{
	S.push(u);
	color[u] = GRAY;
	d[u] = ++time;
	while(!S.empty())
	{
		int v = S.top();
		int x = next(v);
		if(x!=-1 && x!= v)
		{
			color[x] = GRAY;
			S.push(x);
			d[x] = ++time;
		}
		else
		{
			S.pop();
			color[v] = BLACK;
			f[v] = ++time;
		}
	}
}

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

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

	return 0;
}

C++: #include <cstdio>
#include <cstdlib>
#include <string>
#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,M[N][N];
int d[N], color[N],f[N],tt;

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

void dfs(){
    int u;
    tt=0;
    for (u=0;u<n;u++)color[u]=WHITE;

    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,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;
        }
    }
    for(int i=0;i<n;i++) d[i]=-1;
    dfs();
    return 0;
}