Go: package main

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

func main() {
	scn := bufio.NewScanner(os.Stdin)
	scn.Split(bufio.ScanWords)
	nextInt := func() int { scn.Scan(); r, _ := strconv.Atoi(scn.Text()); return r }
	w := bufio.NewWriter(os.Stdout)

	n := nextInt()
	vecs := make([][]int, n)
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			vecs[u-1] = append(vecs[u-1], nextInt()-1)
		}
	}

	ds := make([]int, n)
	fs := make([]int, n)
	founds := make([]bool, n)
	t := 0
	for i := range founds {
		if !founds[i] {
			t = dfs(vecs, ds, fs, founds, i, t)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(w, i+1, ds[i], fs[i])
	}

	w.Flush()
}

func dfs(vecs [][]int, ds, fs []int, founds []bool, i, t int) (time int) {
	t++
	ds[i] = t
	founds[i] = true
	for _, v := range vecs[i] {
		if !founds[v] {
			t = dfs(vecs, ds, fs, founds, v, t)
		}
	}
	t++
	fs[i] = t

	return t
}

C++: // dfs(stack)
#include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
using namespace std;

const int N = 100;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;

int n, M[N][N];
int color[N], d[N], f[N], tt;
int nt[N];

// uに隣接するvを番号順に取得
int next(int u) {
    for (int v = nt[u]; v < n; v++) {
        nt[u] = v + 1;
        if (M[u][v]) return v;
    }
    return -1;
}

// スタックを用いた深さ優先探索
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[v] = BLACK;
            f[u] = ++tt;
        }
    }
}

void dfs() {
    // 初期化
    for (int i = 0; i < n; i++) {
        color[i] = WHITE;
        nt[i] = 0;
    }
    tt = 0;

    // 未訪問のuを始点として深さ優先探索
    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;

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

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>

using namespace std;

int n;
vector<vector<int>> g; 
int timeT = 0;
vector<int> d, f;
 
void dfs(int node){
    timeT++;

    if(d[node] == 0){
        d[node] = timeT;
    }

    for(auto next : g[node]){
        if(d[next] == 0){
            dfs(next);
        }
    }
    
    timeT++;
    if(f[node] == 0){
        f[node] = timeT;
    }
    return;
}
    
int main(){
    
    cin >> n;

    d.assign(n + 1, 0);
    f.assign(n + 1, 0);

    g.assign(n + 1, vector<int>());

    for(int i = 0; i < n; i++)
    {
        int nod, numOut;
        cin  >> nod >> numOut;
        for(int j = 0; j < numOut; j++)
        {
            int temp;
            cin >> temp;
            g[nod].push_back(temp);
        }
    }
    
    for(int i = 1; i <= n; i++)
    {
        if(d[i] == 0){
            dfs(i);
        }
    }

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

    return 0;
}

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

// http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_B

vector<int> map[100];
int found[100];
int finish[100];
bool visit[100];

int dfs(int x, int t) {
	found[x] = t;
	visit[x] = true;
	for (int i = 0; i < map[x].size(); i++) {
		if (visit[map[x][i]]) continue;
		t = dfs(map[x][i], t + 1);
	}
	finish[x] = ++t;
	return t;
}

int main() {
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		int a, b, c;
		cin >> a >> c;
		for (int j = 0; j < c; j++) {
			cin >> b;
			map[a - 1].push_back(b - 1);
		}
	}
	
	int t = 1;
	for (int i = 0; i < n; i++) 
		if (!visit[i]) t = dfs(i, t) + 1;
	
	for (int i = 0; i < n; i++)
		cout << (i + 1) << " " << found[i] << " " << finish[i] << endl;
	return 0;
}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
typedef int long long ll;

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];//グラフの隣接行列
int color[N],d[N],f[N],tt;//状態
int nt[N];

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;
    
    for(int u=0;u<n;u++){
        if(color[u]==WHITE){
            cout<<"a"<<endl;
            dfs_visit(u);
        }
    }
        for(int i=0;i<n;i++){
            cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
        }
}






int main(){

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

return 0;
}

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

static const int MAX=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

using namespace std;

int adj[MAX+1][MAX+1];
int color[MAX+1],d[MAX+1],f[MAX+1];
int n;
int t=0;

void dfs(int u){
  color[u]=GRAY;
  d[u]=++t;
  for(int i=1;i<=n;i++){
    if(adj[u][i]==1 && color[i]==WHITE) dfs(i);
  }
  color[u]=BLACK;
  f[u]=++t;
}

void dfs_init(){
  for(int i=1;i<=n;i++) color[i]=WHITE;
  for(int i=1;i<=n;i++){
    if(color[i]==WHITE) dfs(i);
  }
}

int main(){
  cin >> n;
  for(int i=1;i<=n;i++){
    int u,k; cin >> u >> k;
    for(int i=1;i<=n;i++) adj[u][i]=0;
    for(int i=0;i<k;i++){
      int v; cin >> v;
      adj[u][v]=1;
    }
  }
  dfs_init();
  for(int id=1;id<=n;id++){
    printf("%d %d %d\n",id,d[id],f[id]);
  }
}