Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #include <iostream>
#include <vector>
#include <stack>
using namespace std;
static const int MAX=101;
bool Visited[MAX]; //??\?????????????¢??????????
vector<int> Adjacency[MAX];
int dTime[MAX]; int fTime[MAX]; //?¢??????°??¶??´????¢?????????¶??´
void dfs(int j,int clock)
{

    stack<int> S;
    S.push(j);dTime[j]=++clock;
    Visited[j]=true;
    while(!S.empty())
    {
        int p=S.top(); //???????????¶??????
        if(Adjacency[p].size()==0)
        {
            S.pop();
            fTime[p]=++clock;
            continue;
        }
        int i=0;
        if(Adjacency[p].size())
          while(Visited[Adjacency[p][i]]==true)
          {
            i++;
            if(i==Adjacency[p].size()) //???????°??????????????±?????????????
            {
                S.pop();
                fTime[p]=++clock;
                break;
            }
          }
        if(i==Adjacency[p].size()) continue;
        //if founded
        S.push(Adjacency[p][i]); dTime[Adjacency[p][i]]=++clock;
        Visited[Adjacency[p][i]]=true;
    }
}
int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++) Visited[i]=false;

    for(int i=1;i<=n;i++)
    {
        int p;cin>>p;
        int num;
        cin>>num;

        for(int j=0;j<num;j++)
        {
            int t;
            cin>>t;
            Adjacency[p].push_back(t);
        }
    }
    int clock=0;
    for(int i=1;i<=n;i++)  //???????????????????????°DFS?£?????????????
    {
        if(Visited[i]==false) dfs(i,clock);
    }
    for(int i=1;i<=n;i++)
        cout<<i<<' '<<dTime[i]<<' '<<fTime[i]<<endl;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
#define rep2(i,x,n) for(int i=x; i<(n); i++)
#define ALL(n) begin(n),end(n)
using namespace std;
using P = pair<int, int>;
using ll = long long;
using Graph = vector<vector<int>>;

// 難しいね
int main()
{
    // input
    int n;
    cin >> n;
    vector<queue<int>> q(n+1);
    rep2(i,1,n+1){
        int id, num;
        cin >> id >> num;
        rep(j,num){
            int temp;
            cin >> temp;
            q[i].push(temp);
        }
    }


    // solve
    vector<int> d(n+1), f(n+1);
    stack<int> place;
    place.push(1);
    int time = 0;
    while(place.size()){
        int now = place.top();
        if(!d[now]) d[now] = ++time;

        while(q[now].size()){
            if(!d[q[now].front()]){
                place.push(q[now].front());
                q[now].pop();
                break;
            }else{
                q[now].pop();
            }
        }
        if(now == place.top()){
            place.pop();
            f[now] = ++time;
        }
        if(place.size() == 0){
            rep2(i,1,n+1){
                if(d[i]==0){place.push(i); break;}
            }
        }
    }

    // output
    rep2(i,1,n+1) cout << i << " " << d[i] << " " << f[i] << endl;
    return 0;
}

C++: #include <iostream>

using namespace std;

#define N_MAX 100

int Adj[N_MAX][N_MAX] = {};
int Chk[N_MAX][2] = {};
int search_time = 1;

void dfs(int v, int num_node);

int main()
{
    int n, i, u, k, v, j;

    cin >> n;

    //??£??\???????????????
    for (i = 0; i < n; i++) {
        cin >> u >> k;
        while (k-- > 0) {
            cin >> v;
            Adj[u-1][v-1] = 1;
        }
    }
/*
    cout << "show Adjacency matrix" << endl;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n ; j++) {
            if (j == n - 1)
                cout << Adj[i][j] << endl;
            else
                cout << Adj[i][j] << ' ';
        }
    }
*/
    //??¢?´¢??????
//    dfs(1, n);
    for (i = 1; i <= n; i++) {
        if (Chk[i-1][0] == 0)
            dfs(i, n);
    }

    for(i = 0; i < n; i++) {
        cout << i+1 << ' ' << Chk[i][0] << ' ' << Chk[i][1] << ' ' <<  endl;
    }

    return 0;
}

void dfs(int v, int num_node) {

//    cout << "dfs node : " << v << " time : " << search_time << endl;

    int i;
    //v???????????????????¨????
    if (Chk[v-1][0] == 0) //????????????node?????´???
        Chk[v-1][0] = search_time++;
    else {                //??¢??\???node?????´???
    //    search_time++;
        return;
    }

    //v???????????¢?´¢
    for (i = 1; i <= num_node; i++) {
        if (Adj[v-1][i -1] == 1) {
            dfs(i, num_node);
        }
    }

    //?????±??¨?????§??¢?´¢??????????????????
    //v???????????????????¨????
    Chk[v-1][1] = search_time++;
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
#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;
    for (v = 0; v < n; v++) {
        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;
    cin >> n;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n; j++) {
            m[i][j] = 0;
        }
    }
    for (i = 0; i < n; i++) {
        cin >> u >> k;
        u--;
        for (j = 0; j < k; j++) {
            cin >> v;
            v--;
            m[u][v] = 1;
        }
    }
    dfs();
    return 0;
}