Go: package main

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

// repr state of visited node
// WHITE yet visit
// GEAY  visiting
// BLACK visited
const (
	WHITE int = iota
	GRAY
	BLACK
)

type dfsGraph struct {
	g      [][]int
	colors []int
	stime  []int // Start time of visiting node
	ftime  []int // Finish time of visiting node
}

var time int

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func (dg dfsGraph) dfsVisit(u int) {
	// 頂点uを訪問中に設定
	dg.colors[u] = GRAY
	time++
	dg.stime[u] = time

	// uの隣接nodeを訪問
	for v := 0; v < len(dg.g); v++ {
		if dg.g[u][v] == 0 {
			continue // 辺がなければスキップ
		}

		// vが未訪問なら訪問
		if dg.colors[v] == WHITE {
			dg.dfsVisit(v)
		}
	}

	// 頂点uを訪問済みに設定
	dg.colors[u] = BLACK
	time++
	dg.ftime[u] = time
}

func (dg dfsGraph) dfs() {
	for i := 0; i < len(dg.g); i++ {
		if dg.colors[i] == WHITE {
			dg.dfsVisit(i)
		}
	}
}

func (dg dfsGraph) printDfsTime() {
	for i := 0; i < len(dg.g); i++ {
		fmt.Printf("%d %d %d\n", i+1, dg.stime[i], dg.ftime[i])
	}
}

func main() {
	adj := makeAdjList()
	colors := make([]int, len(adj))
	stime := make([]int, len(adj))
	ftime := make([]int, len(adj))
	graph := dfsGraph{adj, colors, stime, ftime}
	graph.dfs()
	graph.printDfsTime()
}

C++: #include "bits/stdc++.h"
#include <unordered_set>

#define _CRT_SECURE_NO_WARNINGS

#define REP(i, n) for(decltype(n) i = 0; i < (n); i++)
#define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++)
#define REP3(i, x, n) for(decltype(x) i = (x); i <= (n); i++)
#define RREP(i, n) for (decltype(n) i = (n) - 1; i >= 0; i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

using namespace std;

const int INF = 1000000000;
const double PI = 3.1415926535897932384626433832795;

// N, E, S, W
const int dx[4] = { -1, 0,  1,  0 };
const int dy[4] = { 0, 1,  0, -1 };

using LL = long long int;
using LD = long double;
using pii = pair<int, int>;
using pdd = pair<double, double>;
using pll = pair<LL, LL>;
using vi = vector<int>;
using vd = vector<double>;
using vs = vector<string>;
using vvi = vector<vi>;
using vll = vector<LL>;

//==============================================
int n, tt = 0;
vvi M;
vi D, F, searchStatus;

// ??±???????????¢?´¢
void antDfs(int u) {
	searchStatus[u] = 0;
	D[u] = ++tt;
	REP3(i, 1, n) {
		if (M[u][i] == 0) continue;

		if (searchStatus[i] == -1) {
			antDfs(i);
		}
	}
	F[u] = ++tt;
	searchStatus[u] = 1;
}

void print() {
	REP3(i, 1, n) {
		cout << i << " " << D[i] << " " << F[i] << "\n";
	}
}

void solve() {
	// ?????¢?´¢??¶???????¨????
	//REP3(i, 1, n) searchStatus[i] = -1;

	REP3(i, 1, n) {
		if (searchStatus[i] == -1) {
			antDfs(i);
		}
	}

	// ??????
	print();
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n;
	
	M.resize(n + 1, vi(n + 1));
	D.resize(n + 1);
	F.resize(n + 1);
	searchStatus.resize(n + 1, -1);

	
	int u, k, v;
	REP3(i, 1, n) {
		cin >> u >> k;
		REP3(j, 1, k) {
			cin >> v;
			M[u][v] = 1;
		}
	}

	solve();
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <string>
#include <cstdio>
#include <queue>
#include <list>
using namespace std;

int n;

struct Node{
public:
  int id, d, f, flag;
  vector<int> c;
  Node(){d = 1000000007;f = flag = 0;}
};

vector<Node> v(101);

void rec(int id, int &t){
  if(v[id].flag)return;
  else          v[id].flag = 1;
  v[id].d = min(v[id].d, ++t);
  for(int i=0;i<v[id].c.size();i++) {
    rec(v[id].c[i], t);
  }
  v[id].f = max(v[id].f, ++t);
}


bool asc(const Node &right, const Node &left){return right.id < left.id;}

int main(){
  cin >> n;
  
  v[0].id = 0;  
  for(int i=1;i<=n;i++){
    int t, a;  cin >> a >> t;
    vector<int> b(t);
    for(int j=0;j<t;j++){
      int val;cin >> val;
      b[j] = val;
    }
    v[a].id = a;
    v[a].c = b;
  }
  sort(v.begin(), v.end(), asc);

  int ti = 0;
  for(int i=1;i<=n;i++){
    rec(i, ti);
  }

  for(int i=1;i<=n;i++){
    printf("%d %d %d", v[i].id, v[i].d, v[i].f);
    if(i != n)printf("\n");
  }
  return 0;
}

C++: #include<iostream>
#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;

void dfs_visit(int u){
    int v;
    color[u]=GRAY;
    d[u]=++tt;
 
    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;
}

void dfs(){
    int u;
 
    for(u=0; u<n; u++){
        color[u]=WHITE;
    }
    tt=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(){
    int i,j,k,u,v;
    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>
using namespace std;

int n,v,u,k,Time,data[101][101],d[101],f[101];

//dfs
void visit(int u){
  int v;
  d[u] = Time++;
 
  for(v = 1; v <= n; v++){
    if(data[u][v]&d[v]==0)
      visit(v);
  }
  f[u] = Time++;
}
 
int main(){
  cin >> n;
  
  //初期化
  Time = 1;
  for(int i = 1; i <= n; i++){
    for(int j = 1; j <= n; j++){
      data[i][j]=0;
      d[j]=0;
      f[j]=0;
    }
  }
  
  //入力
  for(int i = 0; i < n; i++){
    cin >> u >> k;
    for(int j = 0; j < k; j++){
      cin >> v;
      data[u][v]=1;
    }
  }
  
  //dfs
  for(int i = 1;i <= n; i++){
    if(d[i]==0)visit(i);
  }
  
  //出力
  for(int i = 1;i <= n; i++){
    cout << i << " " << d[i] << " " << f[i] << endl;
  }
  
  return 0;
}

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

#define MAX 100
#define FND -1
#define CMP -2

int n, G_list[MAX+1];
int G[MAX+1][MAX+1];
int d[MAX+1][3];

void make_graph(void){
  scanf("%d", &n);

  for(int i=0; i<n; i++){
    int cnt, num, m;

    scanf("%d %d", &num, &cnt);
    G_list[i]=num;

    for(int j=0; j<cnt; j++){
      scanf("%d", &m);
      G[num][m]=1;
    }
  }
}

void check_depth(int data){
  stack<int> S;
  static int tm=0;
  
  S.push(data);
  d[data][0]=++tm;
  d[data][2]=FND;
  
  while(!S.empty()){
    int top=S.top();
    int next=-5;

    for(int i=0; i<n; i++){
      if(G[top][G_list[i]] == 1 && d[G_list[i]][2] == 0){
	next=G_list[i];
	S.push(next);
	d[next][2]=FND;
	d[next][0]=++tm;
	break;
      }
    }

    if(next == -5){
      d[S.top()][2]=CMP;
      d[S.top()][1]=++tm;
      S.pop();
    }

  }
}

void set_depth(void){

  for(int i=0; i<n; i++){
    if(d[G_list[i]][2] == 0) check_depth(G_list[i]);
  }
}

void print(void){

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

int main(void){

  make_graph();
  set_depth();
  print();
  
  return 0;
}