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 <cstdio>

typedef struct vertex_{
    int found;
    int d;
    int f;
}vertex;

int search(vertex *array, int (*A)[101], int id, int n, int time){
    if(array[id].found)return time;
    array[id].found=1;
    time++;
    array[id].d=time;
    for(int i=1;i<=n;i++){
        if(A[id][i])time=search(array,A,i,n,time);
    }
    time++;
    array[id].f=time;
    return time;
}

int main(){
    int i, j, n, u, k, v;
    scanf("%d",&n);
    vertex array[n+1];
    for(i=1;i<=n;i++)array[i].found=0;
    int A[101][101];
    for(i=1;i<=n;i++){
        for(j=1;j<=n;j++){
            A[i][j]=0;
        }
    }
    for(i=1;i<=n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            A[u][v]=1;
        }
    }
    for(i=1;i<=n;i++){
        for(j=1;j<=n;j++){
            printf("%d ",A[i][j]);
        }
        printf("\n");
    }
    int time = 0;
    for(i=1;i<=n;i++)if(array[i].found==0)time += search(array, A, i, n, 0);
    for(i=1;i<=n;i++)printf("%d %d %d\n",i,array[i].d,array[i].f);
    printf("%d\n",time);
    return 0;
}

C++: #include <algorithm>
#include <iostream>
using namespace std;
int n, Time, A[100][100], d[100], f[100];
void dfs (int cur) { //cur????¨????
  d[cur] = Time; //cur????¨??????????????¨????
  Time++;
  for (int i=0; i<n; i++) { //??¨????????????????????????
    if (A[cur-1][i]==1 && d[i+1]==0) //cur??????i??????????????????i???????¨??????????
      dfs (i); //i?????¨??¶
  }
  f[cur] = Time; //cur???????????????????¨????
  Time++;
}

int main () {
  cin >> n; //???????????????
  for (int i=0; i<n; i++) { //?????????
    for (int j=0; j<n; j++)
      A[i][j] = 0;
  }
  while (n>0) {
    int u;
    cin >> u;
    int k;
    while (cin>>k && k>0) {
      int v;
      cin >> v;
      A[u-1][v-1] = 1; //??\???
      k--;
    }
    n--;
  }
  Time = 1;
  for (int i=0; i<n; i++) {
    d[i] = 0;
  }
  for (int i=0; i<n; i++) {
    if (d[i]==0)
      dfs (i); //??¢?´¢
  }
  for (int i=1; i<=n; i++) //??????
    cout << i << " " <<  d[i] << " " << f[i] << endl;
}

C++: #include<iostream>
using namespace std;
#include<stdio.h>

int G[101][102];
int found[101];
int comp[101];   // complete.
int t;  // time.

typedef struct box{ int val; box* next; } box_t;  // stack.

box_t* init()
{
    box_t* head = new box_t;
    head->val = -1;
    head->next = NULL;
    return head;
}

bool isEmpty(box_t* head){ return (head->next == NULL ? true : false); }

box_t* push(box_t* head, int data)
{
    box_t* box = new box_t;
    box->val = data;
    box->next = head->next;
    head->next = box;
    return box;
}

int pop(box_t* head)
{
    if(isEmpty(head)){ return -1; }
    box_t* box = head->next;
    int val;
    head->next = box->next;
    val = box->val;
    delete box;
    return val;
}

int front(box_t* head)
{
    int val;
    if(isEmpty(head)){ return -1; }
    val = head->next->val;
    return val;
}

box_t* stack = init();

void search_loop(int i)
{
    int j, k;
    while(1){
        if(found[i] == 0){
            t++; found[i] = t;
            push(stack, i);
        }
        for(k = G[i][0]; G[i][k] != 0 && found[G[i][k]] != 0; k++);
        if(G[i][k] == 0){
            if(isEmpty(stack)){ return; }
            else{
                j = pop(stack);
                t++; comp[j] = t;
                i = front(stack);
            }
        }else{
            G[i][0] = k + 1;
            i = G[i][k];
        }
    };
    return;
}

int main()
{
    int n, i, j, a, b, e;
    scanf("%d", &n);
    for(i = 1; i <= n; i++){
        G[i][0] = 1;
        for(j = 1; j <= n + 1; j++){ G[i][j] = 0; } }

    for(i = 1; i <= n; i++){
        scanf("%d %d", &a, &e);
        for(j = 1; j <= e; j++){
            scanf("%d", &b); G[a][j] = b; } }  // adjacent representation.

    for(i = 1; i <= n; i++){ found[i] = 0; comp[i] = 0; }
    t = 0;
    while(1){
        for(i = 1; i <= n; i++){
            if(found[i] == 0) break;
        }
        if(i > n) break;
        search_loop(i);
    };

	int f, g, h;
    for(i = 1; i <= n; i++){
		f = i; g = found[i]; h = comp[i];
        printf("%d %d %d\n", f, g, h);
    }
    return 0;
}

C++: #include <bits/stdc++.h>
int n,G[101][101];
int d[101];
int T = 0;
int F[101] = {0};
int k = 0;
 
void visit(int u) {
  int i,j,v;
  T++;  
  d[u] = T;
 
  for(v=0;v<n;v++) {
    if(G[u][v] == 1 && d[v] == 0 ) {
      visit(v);
    }
  }
   
  T++;
  F[u] = T;
 
}
 
 
 
int main() {
   
   
  int i,j,k,l,u,a,t;
 
  for(i=0;i<n;i++) d[i] = 0;
 
  scanf("%d",&n);
 
  for(i=0;i<n+1;i++)
    for(j=0;j<n+1;j++) {
      G[i][j] = 0;
 
    }
 
  for(i=0;i<n;i++){
 
    scanf("%d %d ",&k,&u);
    //    printf("u = %d\n",u);
 
    for(j=0;j<u;j++) {
      scanf("%d",&a);
      G[k -1][a-1] = 1;
      // printf("G[%d][%d] = 1\n",i,k-1);
    }
  }
  for(i=0;i<n;i++) {
    if(d[i] == 0) 
    visit (i);
  }
     
  for(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>
#include <string>
#include <set>
#include <queue>
#include <cmath>
#include <map>

using namespace std;
vector<pair<int,int> > ans(100);
vector<vector<int> > da(100);
vector<bool> ju(100,false);

void dfs(int m,int &ti){
    bool ch=true;
    for(int i=0;i<da[m].size();i++){
        if(!ju[da[m][i]]){
            ju[da[m][i]]=true;
            ch=false;
            ti++;
            ans[da[m][i]].first=ti;
            dfs(da[m][i],ti);
        }
    }
    ti++;
    ans[m].second=ti;
}

int main(){
    int n,ti=0;
    cin >> n;
    for(int i=0;i<n;i++){
        int x;
        cin >> x;
        int y;
        cin >> y;
        vector<int> iin(y);
        for(int j=0;j<y;j++){
            cin >>iin[j];
            iin[j]--;
        }
        da[x-1]=iin;
    }
    for(int i=0;i<n;i++){
        if(!ju[i]){
            ju[i]=true;
            ti++;
            ans[i].first=ti;
            dfs(i,ti);
        }
    }
    for(int i=0;i<n;i++){
        cout << i+1 << ' ' << ans[i].first << ' ' << ans[i].second << endl; 
    }
}