Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

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

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve

const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 最初にiを訪問した時刻。発見時刻
//f[i]: iの隣接リストを訪問し終えた時刻。完了時刻
var color, d, f [MAX]int

func dfs_visit(u int) {
	color[u] = GRAY
	time++
	d[u] = time
	//隣接を調べる
	for v := 0; v < n; v++ {
		if M[u][v] == 0 {
			continue
		}
		//隣接するvが、未訪問だった場合
		if color[v] == WHITE {
			dfs_visit(v)
		}
	}
	//訪問完了処理
	color[u] = BLACK
	time++
	f[u] = time
	//訪問完了
}

func dfs() {
	//初期化
	for u := 0; u < n; u++ {
		color[u] = WHITE
	}
	time = 0

	//未訪問のuを始点として、深さ優先探索
	for u := 0; u < n; u++ {

		if color[u] == WHITE {
			dfs_visit(u)
		}
	}

	for u := 0; u < n; u++ {
		fmt.Println(u+1, d[u], f[u])
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	dfs()

}

C++: #include <bits/stdc++.h>

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;

int n;
int u, k, v;
int hour = 1;
int d[101] = {}, f[101] = {};
int gra[101][101] = {};
int color[101] = {};


void dfs(int u) {
	color[u] = 1;
	d[u] = hour;
	hour++;
	FOR(i, 1, n) {
		if (gra[u][i] == 1 && color[i] == 0) {
			dfs(i);
		}
	}
	color[u] = 2;
	f[u] = hour;
	hour++;
}


int main(void) {
	cin >> n;
	
	FOR(i, 1, n) {
		cin >> u >> k;
		FOR(t, 1, k) {
			cin >> v;
			gra[u][v] = 1;
		}
	}
	d[1] = hour;

	dfs(1);

	FOR(i, 1, n) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}

	return 0;
}

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

using namespace std;

static const int N = 100;

static const int WHITE = 0;

static const int GRAY = 1;

static const int BLACK = 2;




//用递归的方式实现图深度优先搜索


/**
 * color 标记访问状态的数组，
 * M[N][N] 邻接矩阵 如果存在定点i到顶点j的边，则M[i][j]=trul
**/
int n, M[N][N];
int color[N], d[N], f[N], tt;

void dfs(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(v);
        }
    }
    color[u] = BLACK;
    f[u] = ++tt;
}

void dfs() {
    int u;
    for (u = 0; u < n; u++) {
        if (color[u] == WHITE) {
            dfs(u);
        }
    }

    for (u = 0; u < n; u++) {
        cout << u + 1 << " " << d[u] << " " << f[u] << 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 i = 0; i < k; i++) {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }
    dfs();
    return 0;
}

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

using namespace std;

#define MAX 110
int num;
int matrix[MAX][MAX];
int dst[MAX];

void input(){
    cin >> num;
    for(int i=0;i<MAX;i++){
        dst[i] = -1;
        for(int j=0;j<MAX;j++){
            matrix[i][j] = 0;
        }
    }
    for(int i=1;i<=num;i++){
        int v; cin >> v;
        int tmp; cin >>tmp;
        for(int j=0;j<tmp;j++){
            int vi; cin >> vi;
            matrix[v-1][vi-1] = 1;
        }
    }
}

void dfs(){
    stack<int> S;
    S.push(0);
    dst[0] = 0;
    while(S.size() != 0){
        int cur = S.top();
        S.pop();
        if(dst[cur]==-1 || dst[cur]== 0){
            for(int i=0;i<num;i++){
                if(matrix[cur][i]==1){
                    S.push(i);
                }
            }
        }
    }
    for(int i=0;i<num;i++){
        cout << i+1 << " " <<  dst[i] << endl;
    }
}

int main(){
    input();
    dfs();
}

C++: //
// Created by 李青坪 on 2018/11/2.
//

#include <cstdio>
#define MAXN 101
using namespace std;

int graph[MAXN][MAXN];
int nodeTime[MAXN][2];
int countTime = 0;
int n;

void dfs(int i){
    if (nodeTime[i][0] != 0){
        return;
    }
    countTime++;
    nodeTime[i][0] = countTime;
    for (int j = 1; j <= n; ++j) {
        if (graph[i][j] != 0 && nodeTime[j][0] == 0){
            dfs(j);
        }
    }
    countTime++;
    nodeTime[i][1] = countTime;
}

int main(){
    scanf("%d", &n);
    int u, k;
    for (int i = 0; i < n; ++i) {
        scanf("%d %d", &u, &k);
        int node;
        for (int j = 0; j < k; ++j) {
            scanf("%d", &node);
            graph[u][node] = 1;
        }
    }
    for (int m = 1; m <= n; ++m) {
        dfs(m);
    };
    for (int l = 1; l <= n; ++l) {
        printf("%d %d %d\n", l, nodeTime[l][0], nodeTime[l][1]);
    }
}
/*
6
1 2 2 3
2 2 3 4
3 1 5
4 1 6
5 1 6
6 0
 */

C++: #include<queue>
#include<stack>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;

int n, dd[100], f[100], tmap[100][100];
int color[100], t = 1;
stack<int> S;

int a(){
	int d = S.top();
	dd[d] = t;
	t++;
	color[d] = 1;
	for (int i = 1; i <= n; i++){
		if (color[i] == 0 && tmap[d][i] == 1){
			S.push(i);
			a();
		}
	}
	f[d] = t;
	t++;
	return 0;
}


int main(){
	cin >> n;
	for (int i = 0; i < 100; i++){
		dd[i] = f[i] = color[i] = 0;
		for (int j = 0; j < 100; j++){
			tmap[i][j] = 0;
		}
	}

	int u, k, v;

	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			tmap[u][v] = 1;
		}
	}
	S.push(1);
	a();
	for (int i = 1; i <= n; i++){
		cout << i << " " << dd[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);
		}
	}
	
	dfs(0, 1);
	for (int i = 0; i < n; i++)
		cout << (i + 1) << " " << found[i] << " " << finish[i] << endl;
	return 0;
}

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

using namespace std;

int tim = 0;
vector<vector<int>> to;
vector<bool> reached;
vector<int> d;
vector<int> f;



void dfs(int point);

int main()
{
    int n;
    cin >> n;
    to.resize(n+1);
    for(int i = 1; i <= n; i++){
        int m;
        cin >> m;
        cin >> m;
        to[i].resize(m);
        for(int j = 0; j < m; j++){
            cin >> to[i][j];
        }
    }
    
    reached.resize(n+1);
    d.resize(n+1);
    f.resize(n+1);

    dfs(1);

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

    return 0;
}

void dfs(int point)
{
    tim++;
    reached[point] = true;
    d[point] = tim;
    for(int i = 0; i < to[point].size(); i++){
        if(!reached[to[point][i]]){
            dfs(to[point][i]);
        }
    }
    tim++;
    f[point] = tim;
}