Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include<stdio.h>
#define N 105
#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=1;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=1;u<=n;u++)color[u]=WHITE;
     tt=0;
     for(u=1;u<=n;u++)
     {
         if(color[u]==WHITE)dfs_visit(u);
     }
     for(u=1;u<=n;u++){
        printf("%d %d %d\n",u,d[u],f[u]);
     }
}
int main()
{
    int u,v,k,i,j;
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++)M[i][j]=0;
    }
    for(i=1;i<=n;i++)
    {
        scanf("%d%d",&u,&k);
        //u--;
        for(j=1;j<=k;j++)
        {
            scanf("%d",&v);
        //v--;
            M[u][v]=1;
        }
    }
    dfs();
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int N, T = 0; 
vector<vector<int>> G(110);

vector<int> d(110, -1), f(110, -1);

void dfs(int v){
  T++; d[v] = T;
  for(int i=0; i<G[v].size(); i++){
    int u = G[v][i];

    if(d[u] == -1){
      //cout << v << " " << u << " " << T << endl;
      dfs(G[v][i]);
    }
  }
  T++;
  f[v] = T;
}

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

  for(int i=0; i<N; i++){
    if(d[i] == -1) dfs(i);
  }
  
  for(int id=0; id<N; id++){
    cout << id+1 << " "<< d[id] << " " << f[id] << endl; 
  }
}

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

void dfs(int n, int &t, vector<vector<int>>& g, vector<int>& d, vector<int>& f, vector<bool>& seen)
{
    t++;
    if (d[n] == 0) d[n] = t;
    seen[n] = true;
    for (int i = 0; i < g[n].size(); i++)
    {
        if (seen[g[n][i]]) continue;
        dfs(g[n][i], t, g, d, f, seen);
    }
    t++;
    f[n] = t;
}

int main()
{
    int n; cin >> n;
    vector<vector<int>> g(n, vector<int>());
    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--;
            g[u].push_back(v);
        }
    } 
    vector<int> d(n, 0);
    vector<int> f(n, 0);
    vector<bool> seen(n, false);
    int t = 0;
    for (int i = 0; i < n; i++)
        if (seen[i] == false)
            dfs(i, t, g, d, f, seen);
    for (int i = 0; i < n; i++)
    {
        cout << i + 1 << " " <<  d[i] << " " << f[i] << endl;
    }
}

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

int n;
int t; //mytime?????????????????§???????´?
int mytime1[110],mytime2[110]; //?????§??????
int G[110][110];
int c[110];

void dfs(int cur){
	t+=1;
	mytime1[cur]=t;
	c[cur]=1;
	for(int dst=0; dst<n; ++dst){
		if(G[dst][cur]==1&&c[dst]==0){
			dfs(dst);
			t += 1;
		}
	} 
	mytime2[cur]=t;
}


int main()
{
	vector<int> v[110];
	cin>>n;
	for(int i=0;i<n;i++){
		int u,k;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			int tmp;
			cin>>tmp;
			v[u].push_back(tmp);
		}
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			G[i][j]=0;
		}
	}
	for(int i=1;i<n+1;i++){
		for(int j=0;j<v[i].size();j++){
			G[i-1][v[i][j]-1]=1; //
		}
	}
	dfs(0);
	for(int i=0;i<n;i++){
		cout<<(i+1)<<' '<<mytime1[i]<<" "<<mytime2[i] <<endl;
	}
}