Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve(parseProblem())
}

type graph struct {
	size  int
	edges [][]int
}

func parseProblem() *graph {
	n := scanInt(sc)
	g := &graph{
		size:  n,
		edges: make([][]int, n),
	}
	for i := 0; i < g.size; i++ {
		_ = scanInt(sc)
		k := scanInt(sc)
		g.edges[i] = make([]int, k)
		for j := 0; j < k; j++ {
			g.edges[i][j] = scanInt(sc) - 1
		}
	}
	return g
}

func resolve(g *graph) {
	ds := make([]int, g.size)
	fs := make([]int, g.size)
	time := 0
	for i := 0; i < len(ds); i++ {
		if ds[i] == 0 {
			time++
			time = _dfs(ds, fs, time, g, i)
		}
	}
	for i := 0; i < len(ds); i++ {
		fmt.Println(i+1, ds[i], fs[i])
	}
	return
}

func _dfs(ds, fs []int, time int, g *graph, idx int) int {
	ds[idx] = time
	for _, next := range g.edges[idx] {
		if ds[next] > 0 {
			continue
		}
		time++
		time = _dfs(ds, fs, time, g, next)
	}
	time++
	fs[idx] = time
	return time
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include<iostream>
#include<vector>
#include<limits.h>
#include<stack>
#include<string>
using namespace std;

vector< vector<int> > L(105);
vector<int> d(105,0);
vector<int> f(105,0);
vector<bool> c(105,0);
int count=0;

int out(vector<int> &A){
	int n=A.size();
	int i;
	if (n==0){
		cout << "nothing" <<endl;
	}else if(n==1){
		cout << A[0] << endl;
	}else{
		for (i=0;i<=n-2;i++){
			cout << A[i] << " ";
		}
		cout << A[n-1] <<endl;
	}
}

void dfs (int v){
	if(c[v]) return ;
	count++;
	c[v]=1;
	d[v]=count;
	for (int i=0;i<L[v].size();i++){
		dfs(L[v][i]);
	}
	count++;
	f[v]=count;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	
	int n,i,j;
	cin >> n;
	
	int id, deg, v;
	for (i=0;i<n;i++){
		cin >> id >> deg;
		for (j=0;j<deg;j++){
			cin >> v;
			L[id-1].push_back(v-1);
		}
	}
	for (i=0;i<n;i++){
		dfs(i);
	}
	for (i=1;i<n+1;i++){
		cout << i << " " << d[i-1] << " " << f[i-1] <<endl;
	}
	return 0;
}

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

int n, t;
vector<vector<int> > graph;
vector<int> d, f;
vector<bool> visited;

void dfs(int node){
    visited[node] = true;
    d[node] = t;
    t++;
    for(int i=0;i<int(graph[node].size());i++){
        int nxt = graph[node][i];
        if(!visited[nxt]){
            dfs(nxt);
        }
    }
    f[node] = t;
    t++;
}

int main(){
    cin >> n;
    graph.resize(n);
    d.resize(n);
    f.resize(n);
    visited.resize(n, false);
    for(int i=0;i<n;i++){
        int u, k;
        cin >> u >> k;
        for(int j=0;j<k;j++){
            int v;
            cin >> v;
            graph[u-1].push_back(v-1);
        }
    }
    t = 1;
    for(int i=0;i<n;i++){
        if(!visited[i]){
            dfs(i);
        }
    }
    for(int i=0;i<n;i++){
        cout << i+1 << " " << d[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: #include<stdio.h>
#include<algorithm>
#include<stack>
#include<string.h>
using namespace std;
#define INFTY 2000000001
#define MAX 101
#define WHITE 0
#define GRAY 1
#define BLACK 2

int n = 0;
int adl[MAX][MAX], deg[MAX];
int adm[MAX][MAX];
int color[MAX];
int d[MAX][2];
stack<int> depth;


void dfs() {
  int time = 1;
  for ( int i = 0; i < n; i++ ) {
    color[i] = WHITE;
  }
  depth.push(0);
  d[0][0] = time++;

  while (!depth.empty()) {
    int top = depth.top();

    int next;
    for (int i = 0; i < n; i++) {
      next = i;
      if (adm[top][i] == 1 && color[i] == WHITE) {
        depth.push(i);
        d[i][0] = time++;

        color[i] = GRAY;
        break;
      }
      next = n;
    }

    if (next == n) {
      color[top] = BLACK;
      d[top][1] = time++;
      depth.pop();
    }
  }
}

int main() {
  scanf("%d", &n);
  for ( int i = 0; i < n; i++ ) {
    for ( int j = 0; j < n; j++ ) {
      adm[i][j] = 0;
    }
  }
  for ( int i = 0; i < n; i++ ) {
    int num;
    scanf("%d", &num);
    num--;
    scanf("%d", &deg[num]);
    for ( int j = 0; j < deg[num]; j++) {
      scanf("%d", &adl[num][j]);
      adl[num][j]--;
      adm[num][adl[num][j]] = 1;
    }
  }

  dfs();

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



  return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include<cstdio>

bool table[102][102] = {};
int color[102] = {}; //0:?????¢?´¢???1:?¨??????????, 2:??¢?´¢??????
int n, counter = 0;
int t_visit[102] = {};
int t_finish[102] = {};

void DFS(int y) {
	
	for (int j = 0; j <= n - 1;j++) {

		//?¨????or??¢?´¢???????????£???????????????
		if ((table[y][j] == 1)&&(color[j] == 0)) {
			color[y] = 1; //?¨???????????????????
			if (t_visit[y] == 0) t_visit[y] = ++counter;
			DFS(j);
		}

	}

	color[y] = 2; //??¢?´¢???????????????
	if (t_visit[y] == 0) t_visit[y] = ++counter;
	if (t_finish[y] == 0) t_finish[y] = ++counter;
	
}

int main(void) {
	int u, k, s;

	scanf("%d", &n);

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

	DFS(0);

	for (int i = 0; i <= n - 1;i++) {
		printf("%d %d %d\n", i + 1, t_visit[i], t_finish[i]);
	}

	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,M[n][n];
int color[N],d[N],f[N],tt;
int nt[N];

//????????????????????????u?????????v
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;

    //??\????????????u?????????????????±?????????????´¢
    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();
}

C++: #include <iostream>
using namespace std;
int t = 1;
int d[100], f[100];
int a[100][100];
int N;
void dfs(int cur) {
 d[cur] = t;
 t++;
 for (int i=0; i<N; i++) {
  if (a[cur][i] == 1 && d[i] == 0) {
   dfs(i);
  }
 }
 f[cur] = t;
 t++;
}

int main() {
 cin >> N;
 for (int i=0; i<N; i++) {
  for (int j=0; j<N; j++) {
   a[i][j] = 0;
  }
  d[i] = 0;
  f[i] = 0;
 }
 for (int i=0; i<N; i++) {
  int u, k;
  cin >> u >> k;
  for (int j=0; j<k; j++) {
   int v;
   cin >> v;
   a[u-1][v-1] = 1;
  }
 }
 for (int i=0; i<N; i++) {
  if (d[i] == 0) { dfs(i); }
 }
 for (int i=0; i<N; i++) {
  cout << i+1 << " " << d[i] << " " << f[i] << endl;
 }
}