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))
}

Python: 
def dfs(node_id):
    global current_time #書かないとローカル変数扱いされる
    go_time[node_id] = current_time
    current_time += 1

    for next_node in G[node_id]:

        if visited[next_node] == True:
            continue
        visited[next_node] = True
        dfs(next_node)

    back_time[node_id] = current_time
    current_time += 1


V = int(input())

G = [[] for i in range(V)]

visited = [False]*V

go_time = [0]*V
back_time = [0]*V

for loop in range(V):
    node_id,num,*tmp_adj = list(map(int,input().split()))
    node_id -= 1
    for i in range(num):
        G[node_id].append(tmp_adj[i]-1)

current_time = 1

for i in range(V):
    if visited[i] == True:
        continue
    visited[i] = True
    dfs(i)

for i in range(V):
    print("%d %d %d"%(i+1,go_time[i],back_time[i]))

Python: n = int(input())
G = []
checked = [False for i in range(n + 1)]
d = [0 for i in range(n + 1)]
f = [0 for i in range(n + 1)]
G.append([])
for i in range(n):
    u, k, *v = map(int, input().split())
    G.append(v)

timestamp = 1

def dfs(id):
    global timestamp

    checked[id] = True
    d[id] = timestamp
    timestamp += 1
    for v in G[id]:
        if not checked[v]:
            dfs(v)
    f[id] = timestamp
    timestamp += 1

for id in range(1, n + 1):
    if not checked[id]:
        dfs(id)

for i in range(1, n + 1):
    print("{0} {1} {2}".format(i, d[i], f[i]))

Python: n = int(input())
A = [[0 for i in range(n)] for j in range(n)]

for i in range(n):
    u, k, *v = list(map(int, input().split()))
    for j in v:
        A[int(u)-1][int(j)-1] = 1
        # A[int(j)-1][int(u)-1] = 1

for row in A:
    msg = ' '.join(map(str, row))
    # print(msg)

d = [-1] * n
f = [-1] * n

t = 0

# # recursive
# def dfs(u):
#     global t
#     # print('visit:', str(u), str(t))
#     t += 1
#     d[u] = t
#     for i in range(len(A[u])):
#         if A[u][i] == 1 and d[i] == -1:
#             dfs(i)
#     t += 1
#     f[u] = t
            

def get_next(u):
    for i in range(len(A[u])):
        if A[u][i] == 1 and d[i] == -1:
            return i
    return None



def dfs(u):
    t = 1
    s = []
    s.append(u)
    d[u] = t
    while len(s) > 0:
        p = s[-1]
        v = get_next(p)
        # t += 1
        # d[p] = t
        # print('poped:', p)
        t += 1
        if v is None:
            # print('complete:', p)
            s.pop()
            f[p] = t
        else:
            # print('append:', v)

            d[v] = t
            s.append(v)

# def dfs(u):
#     s = []
#     t = 0
#     s.append(u)
    
#     while len(s) > 0:
#         p = s.pop()
#         print('init', str(p), d[p], t)
#         if d[p] > -1:
#             print('完了')
#             t += 1
#             f[p] = t
#         else:
#             t += 1
#             d[p] = t
#             print('---visit:', str(p), str(t), 'at', t)
#             has_node = False
#             for i in range(len(A[p])):
#                 if A[p][i] == 1 and d[i] == -1:
#                     print('reserve:', str(i))
#                     has_node = True
#                     s.append(i)
#                     break
#             if not has_node:
#                 t += 1
#                 f[p] = t
#         # print('H_complete:', str(p), str(t))
            


for i in range(n):
    if d[i] == -1:
        # print('start from:', str(i))
        dfs(i)


for i in range(n):
    print(str(i+1), str(d[i]), str(f[i]))

Python: def d(u):
 global t
 C[u]=1;D[u]=t;t+=1
 for v in M[u]:v=int(v)-1;C[v]or d(v)
 F[u]=t;t+=1
N=int(input());R=range(N)
M=[input().split()[2:]for _ in R]
C,D,F=[0]*N,[0]*N,[0]*N
t=1
for i in R:C[i]or d(i)
for i in R:print(i+1,D[i],F[i])

Python: from enum import Enum, auto

class Color(Enum):
    WHITE = auto() # 未訪問の頂点
    GRAY = auto() # 訪問済みだが, 全ての接点の調査は済んでいない状態の接点
    BLACK = auto() # 訪問, 調査済みの接点

n = int(input())
d = [0 for i in range(n)]
f = [0 for i in range(n)]

colors = [] # 頂点の訪問状態
A = [[0 for j in range(n)] for i in range(n)] # 隣接行列
# stack = [] ## スタックによる実装では頂点の保持が必要 => 再帰によって実装

# 隣接行列の初期化
for i in range(n):
    arr = list(map(int, input().split(' ')))
    u, k, v = arr[0], arr[1], arr[2:]
    for j in range(k):
        A[u-1][v[j]-1] = 1

time = 0
def dfs_init():
    global colors
    colors = [Color.WHITE for i in range(n)]
    dfs(0)

def dfs(u):
    global time
    colors[u] = Color.GRAY
    time += 1
    d[u] = time
    for v in range(n):
        if A[u][v] == 1 and colors[v] == Color.WHITE:
            dfs(v)
    colors[u] = Color.BLACK
    time += 1
    f[u] = time

dfs_init()
for u in range(n):
    if colors[u] == Color.WHITE:
        dfs(u)

# 出力
for i in range(n):
    print(i+1, d[i], f[i])

Python: def dfs_recursive(u):
    global time
    color[u] = 'gray'
    arrive[u] = time
    time += 1
    for v in range(n):
        if adjMat[u][v] == 1 and color[v] == 'white':
            dfs_recursive(v)
    color[u] = 'black'
    finish[u] = time
    time += 1


n = int(input())

adjMat = [[0] * n for _ in range(n)]
color = ['white'] * n
arrive = [0] * n
finish = [0] * n
time = 1

for _ in range(n):
    adj = list(map(int, input().split()))
    i = adj[0]
    v = adj[2:]
    for j in v:
        adjMat[i - 1][j - 1] = 1

dfs_recursive(0)

for i in range(n):
    out = ''
    out += '{} {} {}'.format(i + 1, arrive[i], finish[i])
    print(out)

Python: #!/usr/bin/env python3
import sys
sys.setrecursionlimit(15000)
n = int(sys.stdin.readline())

ret = []
inp = sys.stdin.readlines()
G = [None]*(n)
d = [0]*(n)
f = [0]*(n)
def dfs(i,t):
  if d[i] != 0:
    return t
  t = t+1
  d[i] = t
  for j in G[i]:
    t = dfs(j,t)
  f[i] = t+1
  return f[i]
for i in range(n):
  v = list(map(int,inp[i].split()))
  G[v[0]-1] = list(map(lambda x: int(x-1),v[2:]))
#print(G)
t = 0
for j in range(n):
  t = dfs(j,t)

for i in range(n):
  print(i+1,d[i],f[i])