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 <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, i, j;

  cin >> n;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) M[i][j] = 0;
  }

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

  dfs();

  return 0;
}

C++: #include <bits/stdc++.h>
#define r(i,a,n) for(int i=a;i<n;i++)
using namespace std;
int a[101][101],start[101],end[101],n,p=0,v[101];
void dfs(int u){
	if(!v[u]){v[u]++;
	start[u]=++p;
	r(i,1,n+1)if(a[u][i])dfs(i);
	end[u]=++p;}
}
int main(){
	int q,qq,qqq;
	cin>>n;
	r(i,0,n){cin>>q>>qq;
		r(i,0,qq){cin>>qqq;
			a[q][qqq]++;
		}
	}
	dfs(1);
	r(i,1,n+1)cout<<i<<' '<<start[i]<<' '<<end[i]<<endl;
}

C++: #include<iostream>
using namespace std;
int visit[101],d[101],f[101],t;
int n,M[101][101];
static const int WHITE=0;
static const int GRAY=1;

void dfs(int u){
  visit[u]=GRAY;
  d[u]=++t;
  for(int v=0;v<n;v++){
    if(M[u][v]==0) continue;
    if(visit[v]==WHITE) dfs(v);
  }
  f[u]=++t;
}

int main(){
  int u,v,k;
  cin>>n;
  
  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;
    }
  }
  
  for(int i=0;i<n;i++){
    if(visit[i]==WHITE) dfs(i);
  }

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

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105

int main(void) {
	int d[MAX], f[MAX];
	int n, u, k, v, i, j;
	vector<vector<int> > vec;
	vector<int> ve;
	vec.push_back(ve);
	cin >> n;
	for (i = 1; i <= n; i++) {
		ve.clear();
		d[i] = f[i] = 0;
		cin >> u >> k;
		ve.push_back(k);
		while (k--) {
			cin >> v;
			ve.push_back(v);
		}
		vec.push_back(ve);
	}
	stack<int> S_v, S_c;
	int Mytime = 1;
	int now, cnt;
	bool flag;
	for (i = 1; i <= n; i++) {
		if (d[i] != 0) continue;
		S_v.push(i);
		S_c.push(1);
		while (!S_v.empty()) {
			now = S_v.top();
			cnt = S_c.top();
			S_c.pop();
			flag = false;
			if (d[now] == 0) {
				d[now] = Mytime;
				Mytime++;
			}
			while(cnt <= vec[now][0]) {
				if (d[vec[now][cnt]] == 0) {
					flag = true;
					break;
				}
				cnt++;
			}
			if (flag) {
				S_v.push(vec[now][cnt]);
				S_c.push(cnt + 1);
				S_c.push(1);
				continue;
			}
			f[now] = Mytime;
			Mytime++;
			S_v.pop();
		}
	}
	for (i = 1; i <= n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}
}

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

using namespace std;
typedef long long ll;

// #define DEBUG

int set_time = 1;
const int maxint = 1000;
struct timestamp;
vector<int> color;
vector<timestamp> ts;
vector< vector<int> > connective;

struct timestamp
{
    int node;
    int discoverry_time;
    int terminate_time;
};

void init_ts(int n, timestamp *a)
{
    a->node = n;
    a->discoverry_time = -1;
    a->terminate_time = -1;
}

void disp_ts(timestamp a)
{
    cout << a.node + 1 << " " << a.discoverry_time << " " << a.terminate_time << endl;
}

void dfs(int x, timestamp *a, vector<int> v)
{
    color[x] = 1;
    a->discoverry_time = set_time;
    set_time++;
    for (auto itr = v.begin(); itr != v.end(); itr++)
    {   
        if (color[*itr] == -1)
            dfs(*itr, &ts[*itr], connective[*itr]);
    }

    a->terminate_time = set_time;
    set_time++;
    
}

int main()
{

#ifdef DEBUG
    cout << "DEBUG MODE" << endl;
    ifstream in("input.txt"); //for debug
    cin.rdbuf(in.rdbuf());    //for debug
#endif

    int n, v, k, x;
    cin >> n;
    timestamp tsi;
    connective.resize(n);
    for (int i = 0; i < n; i++)
    {
        cin >> v >> k;
        color.push_back(-1);
        init_ts(i, &tsi);
        ts.push_back(tsi);
        for (int j = 0; j < k; j++)
        {
            cin >> x;
            connective[i].push_back(x-1);
        }
        
    }
    for (int i = 0; i < n; i++){
        if (color[i] == -1)
            dfs(i, &ts[i], connective[i]);
    }

    for_each(ts.begin(), ts.end(), disp_ts);

    return 0;
}


// getline(cin,s);
// a = strtok(s, ",");  ","で分解
// for (int i = 0; i < n; i++)