Go: package main

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

/***************************************************************
stackによる深さ優先探索を実装する。
***************************************************************/

const (
	N     = 100
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var (
	n            int
	Adj          [N][N]int
	statusColor  [N]int
	discoverTime [N]int
	finishTime   [N]int
	clock        int
	nt           [N]int
)

/***************************************************************
Stackの定義:
- field
	container: ノードの格納されたスライス
	sp: スタックポインタ
- method
	size(): スタックに積まれているノードの個数を返す
	top(): スタックの一番上に積まれているノードを返す
	isEmpty(): スタックが空かどうかを返す
	pop(): スタックの要素をポップし削除する
	push(): スタックに要素を積む
***************************************************************/

type Stack struct {
	container []int
	sp        int
}

func (s *Stack) size() int {
	return len(s.container)
}

func (s *Stack) top() int {
	return s.container[s.sp]
}

func (s *Stack) isEmpty() bool {
	return s.sp == 0
}

func (s *Stack) pop() int {
	_pop := func() {
		s.container = s.container[:len(s.container)-1]
	}
	defer _pop()
	if s.isEmpty() {
		panic("There is no elements in stack!")
	}
	s.sp--
	return s.container[s.sp]
}

func (s *Stack) push(n int) {
	s.sp++
	s.container[s.sp] = n
}

func next(u int) int {
	for v := nt[u]; v < n; v++ {
		nt[u] = v + 1
		if Adj[u][v] == 1 {
			return v
		}
	}
	return -1
}

func _DFS(target int) {
	for i := 0; i < n; i++ {
		nt[i] = 0
	}
	stack := new(Stack)
	stack.container = make([]int, N+1)
	stack.push(target)
	statusColor[target] = GRAY
	clock++
	discoverTime[target] = clock
	for !stack.isEmpty() {
		u := stack.top()
		v := next(u)
		if v != -1 {
			if statusColor[v] == WHITE {
				statusColor[v] = GRAY
				clock++
				discoverTime[v] = clock
				stack.push(v)
			}
		} else {
			stack.pop()
			statusColor[u] = BLACK
			clock++
			finishTime[u] = clock
		}
	}
}

func DFS() {
	for i := 0; i < n; i++ {
		statusColor[i] = WHITE
		nt[i] = 0
	}
	clock = 0
	for i := 0; i < n; i++ {
		if statusColor[i] == WHITE {
			_DFS(i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, discoverTime[i], finishTime[i])
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			Adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ := strconv.Atoi(scanner.Text())
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		u--
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ := strconv.Atoi(scanner.Text())
			v--
			Adj[u][v] = 1
		}
	}

	DFS()
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <stdlib.h>
#include <string>
#include <vector>
#include<stack>
#include <algorithm>
using namespace std;
#define max 101
#define WHITE 0
#define BLACK 1
#define GRAY -1
int color[max],d[max],f[max];
int t,varry[max][max];
stack<int> s;
int next(int u){
  int nv=-1;
  for(int i=0;i<varry[u][0];i++){
    if(color[varry[u][i+1]]==WHITE){
      nv=varry[u][i+1];
      break;
    }
  }
  
  return nv;
}
void visit(int r){
  int u,v;
  s.push(r);
  d[r]=++t;
  while(!s.empty()){
    u=s.top();
    v=next(u);
    if(v!=-1){
      if(color[v]==WHITE){
	s.push(v);
	color[v]=GRAY;
	d[v]=++t;
      }
    }
    else{
      s.pop();
      color[u]=BLACK;
      f[u]=++t;
      
    }
  }
}
void dfs(int u){
  for(int i=1;i<=u;i++)
    if(color[i]==WHITE)visit(i);
}
int main(){
  int n,u;
  cin>>n;
  for(int k=0;k<n;k++){
    cin>>u;
    cin>>varry[u][0];
    for(int i=0;i<varry[u][0];i++)
      cin>>varry[u][i+1];

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


  return 0;
}

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

void dfs(vector<vector<int>> g, bool seen[], int start, int d[], int f[], int &first)
{
    seen[start] = true;
    d[start] = first++;
    for (auto v : g[start])
    {
        if (seen[v])
        {
            continue;
        }
        dfs(g, seen, v, d, f, first);
    }
    f[start] = first++;
}

int main()
{
    int n;
    int first = 1;
    int last = 1;
    cin >> n;
    int d[n + 1], f[n + 1];
    bool seen[n + 1];
    vector<vector<int>> g(n + 1);
    for (int i = 1; i <= n; i++)
    {
        seen[i] = false;
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            int v;
            cin >> v;
            g[u].push_back(v);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        if (!seen[i])
        {
            dfs(g, seen, i, d, f, first);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
}

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

int D[100];
int a[100][100];

int main() {
  for (int i = 0; i < 100; i++){
    for (int j = 0; j < 100; j++){
	  a[i][j] = 0;
	  }
	 }
	int n,u,k,v;
	cin >>n;
	for (int i = 0; i < n; i++) {
	  cin >> u >> k;
	  for (int j = 0; j < k; j++) {
	    cin >> v;
		a[u][v] = 1;
		}
	  }
queue<int> Q; //整数を管理するキューの定義
  for (int i = 1; i < n+1; i++){
   D[i] = -1;
   }
  int src = 1;
  Q.push(src);
  D[src] = 0; //出発点
  while (! Q.empty()) {
    int cur = Q.front(); //先頭要素を取り出す
	Q.pop();
	for (int dst = 1; dst <= n; dst++) {
    if((a[cur][dst] == 1 && D[dst] == -1)) { //curからdstに辺があり、dstが未訪問なら
	  D[dst] = D[cur] +1;
	  Q.push(dst);
	  }
	}
}

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

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

int n, t=1;
vector<int> d, f;
vector<vector<int>> graph;
vector<int> flg;
void dfs(int v){
    flg[v]=1;
    d[v]=t;
    t++;

    for(int i : graph[v]){
        if(!flg[i]) dfs(i);
    }

    f[v]=t;
    t++;
}

int main() {

    cin >> n;
    d.assign(n+1, 0);
    f.assign(n+1, 0);
    graph.assign(n+1, {});
    flg.assign(n+1, 0);
    int u, k, tmp;
    for(int i=1; i<=n; i++){
        cin >> u >> k;
        for(int j=0; j<k; j++){
            cin >> tmp;
            graph[i].push_back(tmp);
        }
    }
    
    for(int i=1; i<=n; i++){
        if(!flg[i]) dfs(i);
    }

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