Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	ans := make([][2]int, N)
	time := 0
	found := make(map[int]bool)
	var dfs func(cur int)
	dfs = func(cur int) {
		time++
		ans[cur][0] = time
		found[cur] = true
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if !found[next] {
				dfs(G[cur][i])
			}
		}
		time++
		ans[cur][1] = time
	}
	for i := 0; i < N; i++ {
		if !found[i] {
			dfs(i)
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprint(wtr, i+1)
		for j := 0; j < 2; j++ {
			fmt.Fprint(wtr, " ")
			fmt.Fprint(wtr, ans[i][j])
		}
		fmt.Fprintln(wtr)
	}
	wtr.Flush()
}

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

int n, G[MAX][MAX], d[MAX], f[MAX], Mytime;

void dfs(int r) {
	int nt[n + 1], st[n + 1], i;
	for (i = 1; i <= n; i++) {
		nt[i] = 1;
		st[i] = 0;
	}
	stack<int> S;
	S.push(r);
	d[r] = ++Mytime;
	st[r] = 1;
	while (!S.empty()) {
		int u = S.top();
		int v;
		for (v = nt[u]; v <= n; v++) {
			nt[u] = v + 1;
			if (G[u][v] && st[v] == 0) 
				break;
		}
		if (v <= n) {
			d[v] = ++Mytime;
			st[v] = 1;
			S.push(v);
		} else {
			S.pop();
			f[u] = ++Mytime;
		}
	}
}

int main(void) {
	int i, j, u, k, v;
	for (i = 0; i < MAX; i++) {
		d[i] = 0;
		f[i] = 0;
		for (j = 0; j < MAX; j++) {
			G[i][j] = 0;
		}
	}
	Mytime = 0;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u >> k;
		for (j = 0; j < k; j++) {
			cin >> v;
			G[u][v] = 1;
		}
	}
	dfs(1);
	for (i = 1; i <= n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}
}

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

int n;
int time_count = 0;
std::vector<std::pair<int, int>> times;
std::vector<std::vector<int>> vec;

void dfs(int id) {
    if (times[id-1].first != -1) {
        return;
    }
    times[id-1].first = ++time_count; 
    auto l = vec[id];
    for (int i = 1; i <= n; i++) {
        if (id == i)
            continue;
        if (l[i] == 1)
            dfs(i);
    }
    times[id-1].second = ++time_count;
}

int main() {
    std::cin >> n;
    vec.assign(n+1, std::vector<int>(n+1, 0));
    for (int i = 0; i < n; i++) {
        times.push_back(std::make_pair(-1, -1));
    }
    for (int i = 0; i < n; i++) {
        int id, num, d;
        std::cin >> id >> num;
        for (int p = 0; p < num; p++) {
            std::cin >> d;
            vec[id][d] = 1;
        }
    }
    dfs(1);
    
    for (int i = 0; i < n; i++) {
        std::cout << i+1 << " " << times[i].first << " " << times[i].second << std::endl;
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <functional>
#include <map>
#include <cmath>
#include <stack>

using namespace std;

#define MAX 102

int main() {

    int d[MAX]={};
    int f[MAX]={};
    int graph[MAX][MAX]={};

    int n;scanf("%d",&n);

    for(int i=0;i<n;i++){
        int u;scanf("%d",&u);
        int k;scanf("%d",&k);
        for(int j=0;j<k;j++){
            int v;scanf("%d",&v);
            graph[u-1][v-1]=1;
        }
    }

    stack<int> sta;
    int time=1;
    d[0]=time;
    sta.push(0);

    while(sta.size()>=1){
        time++;
        int v=sta.top();
        int nextV;
        bool isNothingConnect=true;
        for(int i=0;i<n;i++){
            if(graph[v][i]==1&&d[i]==0) {
                isNothingConnect = false;
                d[i] = time;
                nextV = i;
                break;
            }
        }

        if(isNothingConnect){
            f[v]=time;
            sta.pop();
        }else{
            sta.push(nextV);
        }

    }

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

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()
#define NIL -1

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

bool adj[105][105];
bool vis[105];
struct node{
	int ft;
	int rt;
};
node v[105];

int n;
int cnt;

void dfs (int cur )
{
	cnt++;
	vis[cur] = true;	
	v[cur].ft = cnt;
	for (int u = 1; u <= n; u++ ){
		if (!vis[u] && adj[cur][u] )
			dfs (u );
	} // end for
	cnt++;
	v[cur].rt = cnt;
}

int main()
{
	memset (adj, false, sizeof (adj ) );
	memset (vis, false, sizeof (vis ) );

	ios_base::sync_with_stdio(0);
	cin >> n;

	rep (i, n ) v[i].ft = NIL, v[i].rt = NIL;

	rep (i, n ){
		int v, k;
		cin >> v >> k;
		while (k-- ){
			int u; cin >> u;
			adj[v][u] = true;
		} // end rep
	} // end rep
	cnt = 0;
	while (true ){
		bool ok = true;
		for (int i = 1; i <= n; i++ ){
			if (v[i].ft == NIL ){
				dfs(i);
				ok = false;
				break;
			} // end if
		} // end for
		if (ok ) break;
	} // end while

	for (int i = 1; i <= n; i++ ){
		cout << i << ' ' << v[i].ft << ' ' << v[i].rt << endl;
	} // end for
	
	return 0;
}