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>
using namespace std;

void search(int i,int *table, int n, int *d, int *f, int *cnt){
	
	++(*cnt);
	d[i] = *cnt;
	
	for(int j=0;j<n;++j){
		if(table[i*n+j]){
			for(int k=0;k<n;++k){
				table[k*n+j] = 0;
			}
			search(j,table,n,d,f,cnt);
		}
	}
	
	++(*cnt);
	f[i] = *cnt;
}

int main() {
	int n,*table,*d,*f, cnt;
	
	cin>>n;
	table = new int[n*n];
	d = new int[n];
	f = new int[n];
	
	for(int i=0;i<n;++i){
		int u,k,v;
		cin>>u>>k;
		for(int j=0;j<k;++j){
			cin>>v;
			table[(u-1)*n+v-1]=1;
		}
	}
	cnt = 0;
	
	while(true){
		int rest = 0;
		for(int i=0;i<n;++i){
			for(int j=0;j<n;++j){
				if(table[i*n+j]){
					rest = 1;
					break;
				}
			}
			if(rest){
				search(i,table,n,d,f,&cnt);
				break;
			}
		}
		if(!rest){
			break;
		}
	}
	
	for(int i=0;i<n;++i){
		cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
	}
	
	return 0;
}

C++: #include <cstdio>
using namespace std;
int tim = 0;
bool vis[107];
int G[107][107], d[107], f[107];
void dfs(int cur) {
	vis[cur] = true;
	d[cur] = ++tim;
	for (int i = 0; G[cur][i]; i++) {
		if (!vis[G[cur][i]]) dfs(G[cur][i]);
	}
	f[cur] = ++tim;
}
int main() {
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
    	int u, k;
    	scanf("%d%d", &u, &k);
    	for (int j = 0; j < k; j++) {
    		scanf("%d", &G[u][j]);
		}
	}
	for (int i = 1; i <= n; i++) {
		if (!vis[i]) dfs(i);
	}
	for (int i = 1; i <= n; i++) {
		printf("%d %d %d\n", i, d[i], f[i]);
	}
    return 0;
}

C++: #include<stdio.h>
#define N 100
#define WHITE 0
#define GREY 1
#define BLACK 2

int n, M[N][N];
int color[N], d[N], f[N], time;

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

void dfs()
{
	int u;
	for(u = 0; u < n; u++)
		color[u] = WHITE;
	time = 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()
{
	scanf("%d", &n);
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++)
			M[i][j] = 0;
	int u, k, v;
	for(int i = 0; i < n; i++)
	{
		scanf("%d%d", &u, &k);
		u--;
		for(int j = 0; j < k; j++)
		{
			scanf("%d", &v);
			v--;
			M[u][v] = 1;
		}
	}
	
	dfs();
}

C++: #include <iostream>
#include <vector>
#include <stack>
#include <cstring>
#define N 101

using namespace std;

int visited[N], nt[N], discovery[N], finish[N], tt, n;
vector<int> G[N];

int next(int u) {
    for (int v = nt[u]; v < G[u].size(); v++) {
        nt[u] = v + 1;
        return G[u][v];
    }
    return -1;
}

void dfs(int r) {
    memset(nt, 0, sizeof(nt));

    stack<int> S;
    S.push(r);

    visited[r] = 1;
    discovery[r] = ++tt;

    while (!S.empty()) {
        int u = S.top();
        int v = next(u);

        if (v != -1) {
            if (visited[v] == 0) {
                visited[v] = 1;
                discovery[v] = ++tt;
                S.push(v);
            }
        }
        else {
            S.pop();
            visited[u] = 1;
            finish[u] = ++tt;
        }
    }
}

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

    memset(visited, 0, sizeof(visited));
    tt = 0;

    for (int i = 0; i < n; i++) {
        if (visited[i] == 0) {
            dfs(i);
        }
    }

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

    return 0;
}

C++: #include <iostream>
#include <stack>

using namespace std;

#define MAX 110
int num;
int matrix[MAX][MAX];
int dst[MAX];
int counter = 0;
int D[MAX];
int F[MAX];

void input(){
    cin >> num;
    for(int i=0;i<MAX;i++){
        dst[i] = -1;
        for(int j=0;j<MAX;j++){
            matrix[i][j] = 0;
        }
    }
    for(int i=1;i<=num;i++){
        int v; cin >> v;
        int tmp; cin >>tmp;
        for(int j=0;j<tmp;j++){
            int vi; cin >> vi;
            matrix[v-1][vi-1] = 1;
        }
    }
}

void dfs(int cur){
    counter++;
    D[cur] = counter;
    for(int i=0; i< num;i++){
        if(matrix[cur][i] == 1 && D[i]== 0)
            dfs(i);
    }
    counter++;
    F[cur] = counter;
    return;
}

int main(){
    input();
    for(int i=0;i<MAX;i++){
        D[i] = 0;
        F[i] = 0;
    }
    dfs(0);
    for(int i=0;i<num;i++){
        cout << i+1 << " " << D[i] << " " << F[i] << endl;
    }
}

C++: #include <iostream>
#include <vector>

using namespace std;

std::vector<int> graph[100];
int d[100]={0},f[100]={0};
int t = 0;

void dfs(int v){
  t++;
  d[v] = t;
  for(const auto &next_v:graph[v]){
    if(d[next_v]==0){
      dfs(next_v);
    }
  }
  t++;
  f[v] = t;
}

int main(){
  int n;
  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;
      graph[u-1].push_back(v-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;
  }
  
  return 0;
}

C++: #include <iostream>
#define LEN 101
using namespace std;
int TIME;
int d[LEN];
int f[LEN];
int num;
int graph[LEN][LEN] = {0};
void dfs(int x){
    TIME++;
    d[x] = TIME;
    for(int i=1;i<num+1;i++){
        if(graph[x][i] == 1 && d[i]==0){
            dfs(i);
        }
    }
    f[x] = ++TIME;
}
int main(){
    int hon;
    int eda;
    int ver;
    cin>>num;
    for(int i=0;i<num;i++){
        cin>>eda;
        cin>>hon;
        for(int j=0;j<hon;j++){
            cin>>ver;
            graph[eda][ver]++;
        }
    }
    for(int i=1;i<num+1;i++){
        if(d[i]==0)
            dfs(i);
    }
    for(int i=1;i<num+1;i++){
        cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
    }
    return 0;
}