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)
	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 <vector>
using namespace std;
vector<vector<int>> adjlist;
int time=1;
vector<int> d;
vector<int> f;
void input(int n){
	vector<int> f={0,0};
	adjlist.push_back(f);
  for(int i=0;i<n;i++){
    vector<int> list;
    int ln;
    cin>>ln;
    list.push_back(ln);
    cin>>ln;
    list.push_back(ln);
    for(int j=0;j<ln;j++){
      int an;
      cin>>an;
      list.push_back(an);
    }
    adjlist.push_back(list);
  }
}

void depth_search(int id){
	vector<int> list=adjlist[id];
	for(int j=0;j<list[1];j++){
		if(d[list[2+j]]<0){
			d[list[2+j]]=++time;
			depth_search(list[2+j]);
		}
	}
	f[id]=++time;
}
 
void print(int n){
  for(int i=1;i<n+1;i++){
    cout<<i<<' '<<d[i]<<' '<<f[i]<<endl;
  }
}
int main(){
  int n;
  cin>>n;
	d=vector<int> (n+1,-1);
	f=vector<int> (n+1,-1);
	d[1]=1;
	f[1]=1;
  input(n);
  depth_search(1);
  print(n);
  return 0;
}

C++: #include <iostream>

using namespace std;
int n,u,k,v,**M,flag[100],s_time[100],f_time[100];
void creat()
{
    cin>>n;
  M=new int*[n];
  for(int i=0;i<n;i++)
    {
      M[i]=new int[n];
      flag[i]=0;
      for(int j=0;j<n;j++)
	M[i][j]=0;
    }
  int count=0;
  while(count<n)
    {
      count++;
      cin>>u>>k;
      for(int i=0;i<k;i++)
	{
	  cin>>v;
	  M[u-1][v-1]=1;
	}
    }
    /*for(int i=0;i<n;i++){
    for(int j=0;j<n;j++)
      cout<<M[i][j]<<' ';
    cout<<endl;
  }*/
}
int time = 0;
void dfs(int cur) {
    time += 1;
    s_time[cur]=time;
    //cout << "visiting " << cur+1 << ' ' << time << endl;
    flag[cur]=1;
    for (int dst=0;dst<n;dst++) {
            if (M[cur][dst]&&!flag[dst]) {
                dfs(dst);
            }
    }
    time += 1;
    f_time[cur]=time;
}
int main()
{
    creat();
    for(int i=0;i<n;i++)
    {
        if(!flag[i])
            dfs(i);
    }
    for(int i=0;i<n;i++)
    {
        cout<<i+1<<' '<<s_time[i]<<' '<<f_time[i]<<endl;
    }
    delete M;
    return 0;
}

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

typedef long long llint;
typedef long double ld;
typedef pair<int,int> P;

#define inf 1e18
#define mod 1000000007
#define sort(v) sort(v.begin(),v.end())
#define reverse(v) reverse(v.begin(),v.end())
#define rep(i,a,n) for(int i=a;i<n;i++)


priority_queue<llint,vector<llint>,greater<llint> > que;
priority_queue<llint> Que;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }


#define N 100

int g[N][N];
int d[N];
int f[N];
int t=0;


bool flag[N];
int n;

void dfs(int i){
    flag[i]=true;
    d[i]=++t;
    rep(j,0,n){
        if(g[i][j]==1 && !flag[j]){
            dfs(j);
        }
    }
    f[i]=++t;
}

void solve(){
    cin >> n;
    int u,k;
    rep(i,0,n){
        cin >> u >> k;
        u--;
        rep(j,0,k){
            int v;
            cin >> v;
            v--;
            g[u][v]=1;
        }
    }
    rep(i,0,n){
        if(!flag[i]){
            dfs(i);
        }
    }
    rep(i,0,n){
        cout << i+1 << " " << d[i] << " " << f[i] << endl;
    }
}

int main(){
    solve();
    return 0;
}

C++: 
#include <iostream>

using namespace std;

int d[100]={0},f[100]={0};
int k[101],v[101][100],n;
int c;
void solve();
void dfs(int point);

int main()
{
	cin>>n;
	for (int i=0; i<n; i++) {
		int t;
		cin>>t;
		cin>>k[t];
		for (int j=0; j<k[t]; j++) {
			cin>>v[t][j];
		}
	}
	solve();
}

void solve() {
	d[1]=1,c=2;
	for (int i=0; i<k[1]; i++) {
		if (d[v[1][i]]==0) {
			dfs(v[1][i]);
		}
	}
	c++;
	f[1]=c;
	for (int i=0; i<n; i++) {
		cout<<i+1<<' '<<d[i+1]<<' '<<f[i+1]<<endl;
	}
}
void dfs(int point)
{
	d[point]=c;
	int i=0;
	c++;
	while (i<k[point]) {
		if (d[v[point][i]]==0) {
			dfs(v[point][i]);
			c++;
		}
		i++;
	}
	if (f[point]==0) {
		f[point]=c;
	}
}

C++: #include<iostream>
#include<stack>

using namespace std;
int d[100],f[100];
int M[100][100];
int n,t=0;

void dfs(int s){
    stack<int> S;
    int u;
    bool found=0;
    
    S.push(s);
    d[s]=++t;
    while( !S.empty() ){
	u=S.top();
	found=0;
	for(int v=0;v<n;v++){
	    if(M[u][v]==1 && d[v]==0){
		S.push(v);
		d[v]=++t;
		found=1;
		break;
	    }
	}
	if(found==0){
	    S.pop();
	    f[u]=++t;
	}
    }
}
    
int main(){
    int u,k,v;

    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(d[i]==0) dfs(i);
    }

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

    return 0;
}