Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	// TODO: always start with 1?
	timer := 1
	visit(1, &timer, childrenMap, timeRecordMap)
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include<iostream>
using namespace std;
int M[100][100] = {};
int color[100] = {};
int d[100] = {}, f[100] = {};
int cot=0;
int n;

void dps(int u) {
	if (color[u] == 0) {
		cot++;
		d[u] = cot;
		color[u]++;
	}

	for (int t = 0;t < n;t++) {
		if (M[u][t] == 1) {
			if(color[t]==0){
			    dps(t);
			}
			
			
		}
	}
	if (color[u] == 1) {
        cot++;
	    f[u] = cot;
		color[u]++;
	}
	
	return;

}
int main(){
	int k,m,j;
	cin >> n;
	for (int i = 0;i < n;i++) {
		cin >> m>>k;
		for (int l = 0;l < k;l++) {
			cin >> j;
			M[m - 1][j - 1] = 1;
		}
	}
	for (int i = 0;i < n;i++) {
		if (color[i] == 0) {
			dps(i);
		}
	}


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

	return 0;
}

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

enum Status {WHITE, GRAY, BLACK};

stack<int> stc;
Status *status;
int *discovered, *finished;
vector<vector<int> > a;
int n, timer;

void dfs(int i){
        if(status[i]==BLACK) return;
        if(status[i]==WHITE){
                discovered[i] = ++timer;
                status[i] = GRAY;
        }
        stc.push(i);

        for(int j=0;j<a[i].size();j++) dfs(a[i][j]);

        if(status[i]==GRAY){
                finished[i] = ++timer;
                status[i] = BLACK;
        }
        stc.pop();
}

int main(){

        cin>>n;
        a = vector<vector<int> >(n, vector<int>());
        status = new Status[n];
        discovered = new int[n];
        finished = new int[n];

        int m, k, r;
        for(int i=0;i<n;i++){
                cin>>r;
                cin>>m;
                for(int j=0;j<m;j++){
                        cin>>k;
                        a[r-1].emplace_back(k-1);
                }
        }
        for(int i=0;i<n;i++) status[i] = WHITE;

        timer = 0;
        dfs(0);


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

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
int n, t, d[101], f[101];
vector< vector<int> >m(101);


void dfs(int u){
    d[u] = ++t;
    int v;
    for(int i=0; i<m[u].size(); i++){
        v = m[u][i];
        if(d[v]==-1){
            dfs(v);
        }
    }
    f[u] = ++t;
    return;
}

int main(){
    //freopen("in.txt", "r", stdin);
    scanf("%d", &n);
    for(int i=0; i<n; i++){
        int id, d, to;
        scanf("%d %d", &id, &d);
        for(int j=0; j<d; j++){
            scanf("%d", &to);
            m[id].push_back(to);
        }
    }
    memset(d, 255, sizeof(d));
    t = -0;

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

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

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

using namespace std;

const int MAX_N = 100;

int n;
int d[MAX_N];
int f[MAX_N];
vector<int> adjlist[MAX_N];

int dfs(const int id, int timestamp) {
    if (d[id - 1] > 0) {
        return timestamp;
    }

    timestamp++;
    d[id - 1] = timestamp;
    for (int i = 0; i < (int) adjlist[id - 1].size(); i++) {
        timestamp = dfs(adjlist[id - 1][i], timestamp);
    }
    timestamp++;
    f[id - 1] = timestamp;

    return timestamp;
}

int main(void) {
    cin >> n;

    for (int i = 0; i < n; i++) {
        int id, m;
        cin >> id >> m;
        for (int j = 0; j < m; j++) {
            int x;
            cin >> x;
            adjlist[id - 1].push_back(x);
        }
    }

    int timestamp = 0;
    for (int i = 0; i < n; i++) {
        int id = i + 1;
        timestamp = dfs(id, timestamp);
    }

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

    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <functional>
#include <iomanip>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <typeinfo>
#define PI 3.14159265359
#define INF 99999999;
#define rep(i, n) for(int i=0; i<n; i++)
#define REP(n) rep(i, n)
#define EPS 1e-10
typedef long long ll;
using namespace std;
typedef pair<int, int> P;

double distanceAB(double xa, double ya, double xb, double yb);
//void trace(int A[], int N);

/*
class Target
{
public:
	vector <string> draw(int n)
	{

	}
};
*/


#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;
	rep(v, n)
	{
		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 u, v, k, i, j;
	
	scanf("%d", &n);
	rep(i, n) rep(j, n) M[i][j] = 0;
	
	rep(i, n)
	{
		scanf("%d %d", &u, &k);
		u--;
		rep(j, k)
		{
			scanf("%d", &v);
			v--;
			M[u][v] = 1;
		}
	}
	
	dfs();
	
	return 0;
}

/*
void trace(int A[], int N)
{
	REP(N)
	{
		if (i > 0) cout << " ";
		cout << A[i];
	}
	cout << endl;
}
*/


double distanceAB(double xa, double ya, double xb, double yb)
{
	return sqrt((xb-xa)*(xb-xa) + (yb-ya)*(yb-ya));
}