Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <iostream>
#include <utility>
#include <string>
#include <algorithm>
#include <set>
#include <queue>
#include <vector>
#define MAX 10010
#define rep(i,p) for(int i=0;i<p;i++)
#define pb push_back
using namespace std;
int n,hoge,foo,visit_time=1;
int graph[MAX][MAX] = {0};
int d[MAX]; // ????????????
int f[MAX]; // ??£??\????????????????????????

void dfs (int cur) {
  // visiting cur
  d[cur] = visit_time;
  visit_time++;

  rep(dst,n) {
    if (graph[cur][dst] == 1 && d[dst] == -1) dfs(dst);
  }
  f[cur] = visit_time;
  visit_time++;
}

int main(){
  cin >> n;
  rep(i,n) {
    d[i] = -1;
    f[i] = -1;
  }
  rep(i,n) {
    cin >> hoge >> foo;
    rep(j,foo) {
      cin >> hoge;
      graph[i][hoge-1] = 1;
    }
  }
  rep(i,n) if (d[i] == -1) dfs(i);
  rep(i,n) cout << i+1 << " " << d[i] << " " << f[i] << endl;
  return 0;
}

C++: #include <iostream>
#include <stack>
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;
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) {
            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++: #if 0
time: 15min
using e[] as a indicator to find whether a node has been searched.						
#endif
#include <iostream>
#include <queue>

using namespace std;

int p[100+10][100+10];
int D[100+10],e[100+10],f[100+10];
int n,a,b,c,t;

void dfs(int cur){
	D[cur] = 1;
	t += 1;
	for (int i=1; i<=n; i++){
		if (p[cur][i]>0 && !D[i]){
			f[i] = t+1;
			dfs(i);
		}
	}
	t += 1;
	e[cur] = t;
}

int main(){
	cin >> n;
	for (int i=1; i<=n; i++){
		cin >> a >> b;
		for (int j=1; j<=b; j++){
			cin >> c;
			p[a][c] = 1;
		}
	}
	f[1] = 1;
	for (int i=1; i<=n; i++){
		if (!D[i]){
			f[i] = !f[i] ? t+1 : f[i];
			dfs(i);
		} 	
	}
	

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