Go: package main

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

var sc = bufio.NewScanner(os.Stdin)
var depth [101]int
var finish [101]int
var d [101]int
var n, time int

func nextInt() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}
func visit(graph [][]int, u int) {
	depth[u] = 1
	time++
	d[u] = time
	for i := 0; i < n; i++ {
		if graph[u][i] == 1 {
			if depth[i] == 0 {
				visit(graph, i)
			}
		}
	}
	depth[u] = 2
	time++
	finish[u] = time
}
func main() {
	sc.Split(bufio.ScanWords)

	n = nextInt()
	graph := make([][]int, n)
	for i := 0; i < n; i++ {
		graph[i] = make([]int, n)
	}
	for i := 0; i < n; i++ {
		s := nextInt()
		t := nextInt()
		if t == 0 {
			continue
		}
		for i := 0; i < t; i++ {
			u := nextInt()
			graph[s-1][u-1] = 1
		}
	}
	for i := 0; i < n; i++ {
		if depth[i] == 0 {
			visit(graph, i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, d[i], finish[i])
	}
}

C++: #include <stdio.h>
#include <string.h>
#define N 110
int n;
int m[N][N];
int used[N];
int time = 1;
int start[N];
int end[N];
void dfs(int u){
    used[u] = 1;
    start[u] = time++;
    for(int v = 1; v <= n; v++){
        if(used[v] == 0 && m[u][v]){
            dfs(v);
        }
    }
    end[u] = time++;
}
int main(){
    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++) used[i] = 0;
    scanf("%d", &n);
    for(int p = 0; p < n; p++){
        int node, k;
        scanf("%d %d", &node, &k);
        for(int i = 0; i < k; i++){
            int b;
            scanf("%d", &b);
            m[node][b] = 1;
        }
    }

    for(int i = 1; i<= n; i++) if(used[i] == 0) dfs(i);
    for(int i = 1; i <= n; i++){
        printf("%d %d %d\n", i, start[i], end[i]);
    }
    return 0;
}

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

#define MAX 100

#define WHITE 0
#define GRAY 1
#define BLACK 2

int T;
int N;

int M[MAX][MAX];
int D[MAX], F[MAX], C[MAX];

void dfs(int u)
{
    C[u] = GRAY;
    D[u] = ++T;

    for (int i = 0; i < N; i++)
    {
        if(M[u][i] == 1 && C[i] == WHITE)
        {
            dfs(i);
        }        
    }
    C[u] = BLACK;
    F[u] = ++T;
}

int main ()
{
    cin >> N;

    for (int i = 0; i < N; i++)
    {
        D[i] = 0;
        F[i] = 0;
        C[i] = WHITE;
        
        for (int j = 0; j < N; j++)
        {
            M[i][j] = 0;
        }
    }

    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--;
            M[u][v] = 1;
        }
    }

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (j > 0)
                cout << " ";
            cout << M[i][j];
        }
        cout << endl;
    }

    T = 0;

    for (int i = 0; i < N; i++)
    {
        if (C[i] == WHITE)
        {
            dfs(i);
        }
    }

    /*
    stack<int> *S = new stack<int>;


    S->push(0);
    C[0] = GRAY;
    D[0] = ++time;

    while (S->size() > 0)
    {
        int u = S->top();
        int v = -1;

        // next 
        for (int i = 0; i < N; i++)
        {
            if (M[u][i] == 1)
            {
                if (C[i] == WHITE)
                {
                    v = i;
                    break;
                }
            }
        }

        if (v != -1)
        {
            C[v] = GRAY;
            D[v] = ++time;
            S->push(v);
        }
        else
        {
            S->pop();
            C[u] = BLACK;
            F[u] = ++time;
        }
    }
*/

    for (int i = 0; i < N; i++)
    {
        cout << i + 1 << " " << D[i] << " " << F[i] << endl;
    }
    return 0;
}

C++: #include <stdio.h>
#define WHITE 0
#define GRAY  1
#define BLACK 2
int color[100];
int d[100],f[100];
int G[100][100];
int n, time = 0;
void dfs(int u)
{
    color[u] = 1;
    d[u] = ++time;
    for (int i = 0; i < n; i++)
    {
        if (G[u][i]==1 && color[i] == 0)
        {
            dfs(i);
        }
    } 
    color[u] = 2;
    f[u] = ++time;
    return;
}
int main()
{
    int k,u,v;
    scanf("%d",&n);
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            G[i][j] = 0; 
        }  
    } 
    for (int i = 0; i < n; i++)
    {
        scanf("%d %d",&u,&k);
        for (int j = 0; j < k; j++)
        {
            scanf("%d",&v);
            G[u-1][v-1] = 1;
        } 
    } 
    for (int i = 0; i < n; i++)
    {
        color[i] = 0; 
        d[i] = 0;
        f[i] = 0;
    } 
    for (int i = 0; i < n; i++)
    {
        if(color[i]==0) dfs(i); 
    } 
    for (int i = 0; i < n; i++)
    {
        printf("%d %d %d\n", i+1, d[i], f[i]); 
    } 
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int n, t;
vector<int> G[110];
vector<int> d(110), f(110), visited(110, -1); 

void dfs_visit(int u) {
    visited[u] = 0;
    d[u] = ++t;
    for (int v = 0; v < G[u].size(); v++) {
        if (visited[G[u][v]] == -1) {
            dfs_visit(G[u][v]);
        }
    }
    visited[u] = 1;
    f[u] = ++t;
}

void dfs() {
    for (int u = 0; u < n; u++) visited[u] = -1;
    t = 0;
    for (int u = 0; u < n; u++) {
        if (visited[u] == -1) dfs_visit(u);
    }
    for (int u = 0; u < n; u++) {
        cout << u + 1 << " " << d[u] << " " << f[u] << endl;
    }
}

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);
        }
    }
    dfs();
}

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

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

//再帰関数による深さ優先探索
void dfs_visit(int u){
    int v;
    color[u] = GRAY;
    d[u] = ++tt; //最初の訪問
    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; //訪問の終了
}

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

    for(u=0; u<n; u++){
        //未訪問のuを始点として深さ優先探索
        if(color[u] == WHITE) dfs_visit(u);
    }
    for(u=0; u<n; u++){
        printf("%d %d %d\n", u+1, d[u], f[u]); //タイムスタンプの出力
    }
}

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(j=0; j<k; j++){
            scanf("%d", &v);
            v--;
            M[u][v] = 1;
        }
    }

    dfs();

    return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
using namespace std;

int timex = 0;

int n;

string *color = new string[n];

int *d = new int[n];

int *f = new int[n];

int c[100][100];

void dfs(int u){
  color[u] = "glay";
  d[u] = ++timex;


  for(int v = 0; v < n; v++){
    if(c[u][v] == 1 && color[v] == "white"){
      dfs(v);
    }
  }

color[u] = "black";
f[u] = ++timex;



}

int main(){

  cin >> n;

  color = new string[n];

  d = new int[n];

  f = new int[n];


  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      c[i][j] = 0;
    }
  }

  for(int i = 0; i < n; i++){
    int x;
    cin >> x;
    int k;
    cin >> k;
    for(int j = 0; j < k; j++){
      int v;
      cin >> v;
      c[i][v - 1] = 1;
    }
  }

  for(int i = 0; i < n; i++){
    color[i] = "white";
  }

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



  for(int i = 0; i < n; i++){
    cout << i + 1 << ' ' << d[i] << ' ' << f[i] << endl;
  }




  return 0;
}