Go: package main

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

var N int
var A [][]int
var t int
var color, d, f []int

const (
	WHITE = iota
	GRAY
	BLACK
)

func dfsVisit(u int) {
	color[u] = GRAY
	t ++
	d[u] = t
	for v:=0; v<N; v++ {
		if A[u][v] == 0 {
			continue
		}
		if color[v] == WHITE {
			dfsVisit(v)
		}
	}
	color[u] = BLACK
	t++
	f[u] = t
}

func dfs() {
	for u:=0; u<N; u++ {
		if color[u] == WHITE {
			dfsVisit(u)
		}
	}
	for u:=0; u<N; u++{
		fmt.Printf("%d %d %d\n", u+1, d[u], f[u])
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	color = make([]int, N)
	d = make([]int, N)
	f = make([]int, N)
	A = make([][]int, N)
	for i:=0; i<N; i++{
		A[i] = make([]int, N)
	}
	for i:=0; i<N; i++{
		index := nextInt(scanner) - 1
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			v := nextInt(scanner) - 1
			A[index][v] = 1
		}
	}
	dfs()
}

Python: def dfs(v, u=0):
    global n, t, d, f, reached
    if len(reached) == n:
        return

    d[u] = t
    t += 1

    reached.add(u + 1)
    for ui in range(v[u][1]):
        next = v[u][2 + ui]
        if next in reached:
            continue
        dfs(v, next - 1)

    f[u] = t
    t += 1


n = int(input())
v = []
for _ in range(n):
    v.append(list(map(int, input().split())))

t = 1
d = [0] * n
f = [0] * n
reached = set()


for ui in range(n):
    if ui + 1 not in reached:
        dfs(v, ui)

for ui in range(n):
    print('%d %d %d' % (ui + 1, d[ui], f[ui]))

Python: import sys

n = int(input())
G = [None]*(n+1)
for i in range(n):
    u, k, *vs = map(int, input().split())
    G[u] = vs

d = [-1]*(n+1)
f = [-1]*(n+1)
lb = iter(range(1, 2*n+1)).__next__
def dfs(v):
    d[v] = lb()
    for w in G[v]:
        if d[w] != -1: #already visited
            continue
        dfs(w)
    f[v] = lb()

for v in range(1, n+1):
    if d[v] != -1:
        continue
    dfs(v)

for v in range(1, n+1):
    print(f"{v} {d[v]} {f[v]}")

Python: 
d = None
f = None


def dfs(g, cur, time):
    global d, f
    d[cur] = time
    for next in g[cur]:
        if d[next] == 0:
            time = dfs(g, next, time+1)
    f[cur] = time + 1
    return time + 1


def main():
    global d, f
    n = int(input())
    g = [[] for _ in range(n)]
    d = [0 for _ in range(n)]
    f = [0 for _ in range(n)]
    for _ in range(n):
        inp = list(map(int, input().split()))
        m = inp[0] - 1
        k = inp[1]
        for i in range(k):
            g[m].append(inp[i+2] - 1)
    time = 1
    for i in range(n):
        if d[i] == 0:
            time = dfs(g, i, time) + 1
    for i in range(n):
        print(i+1, d[i], f[i])


if __name__ == '__main__':
    main()

Python: n = int(input())
trees = [[]]
for i in range(n):
    edges = []
    s = list(map(int, input().split()))
    num = s[1]
    if s[1] != 0:
        edges = s[2:2+num]
    trees.append(edges)

d = [0] * (n+1)
f = [0] * (n+1)


def dfs(x, i=0):
    for y in trees[x]:
        if d[y] != 0:
            continue
        d[y] = i
        i += 1
        i = dfs(y, i)
    f[x] = i
    i += 1
    return i


i = 1
for j in range(1, n+1):
    if d[j] != 0:
        continue
    else:
        d[j] = i
        i += 1
    i = dfs(j, i)
for i in range(1, n+1):
    print(i, d[i], f[i])

Python: def dfs(v, cnt):
    D[v] = cnt
    cnt += 1
    for c in edge[v]:
        if D[c] == -1:
            cnt = dfs(c, cnt)
    F[v] = cnt
    cnt += 1
    return cnt


V = int(input())
edge = [[] for _ in range(V)]
for _ in range(V):
    u, _, *v = map(lambda x: int(x)-1, input().split())
    edge[u] = sorted(v)
D, F = [-1] * V, [-1] * V
c = 1
for i in range(V):
    if D[i] == -1:
        c = dfs(i, c)
for i, (d, f) in enumerate(zip(D, F)):
    print(i, d, f)

Python: import sys
input = sys.stdin.readline
d = []
f = []
time = 0
def search(r):
    global d,f,time,s
    if d[r] == 0:
        time += 1
        d[r] = time
    else:
        return
    for x in s[r]:
        search(x)
    time += 1
    f[r] = time


n = int(input())
s = [[] for i in range(n+1)]
for _ in range(n):
    d = list(map(int,input().split()))
    s[d[0]] = d[2:]

d = [0 for _ in range(n+1)]
f = [0 for _ in range(n+1)]

for i in range(1,n+1):
    if d[i] == 0:
        search(i)

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

Python: n = int(input()) # 点の総数
path = list() # path[p] : 点pから行ける点のリスト
path.append([])
for _ in range(n):
    tmp = list(map(int, input().split())) # tmp[0]から行ける点はtmp[1]個あり、それはtmp[2:]
    path.append(tmp[2:])

d = [0]*(n+1) # 最初に発見した時刻
f = [0]*(n+1) # 隣接リストを調べ終えた時刻

TIME = 0

def dfs(p, d, f):
    global TIME
    TIME += 1
    d[p] = TIME # 来訪時刻の記録

    for nxt in path[p]: #繋がってる点の内
        if d[nxt] == 0: # 未探索の場合には
            dfs(nxt, d, f) # 先に進む
    
    TIME += 1
    f[p] = TIME # 繋がってる全ての点を探索し終えたらその点でやることは終わり

    
    return     
    
for start in range(1, n+1):
    if d[start] == 0:
        dfs(start, d, f)

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

Python: N = int(input())

from collections import deque,defaultdict
G = defaultdict(deque)
for i in range(1,N+1):
    t = [int(i) for i in input().split(' ')]
    for j in range(t[1]):
        G[t[0]].append(t[j+2])

time = 1
arrive_time = [-1] * (N + 1) # 到着時刻
finish_time = [-1] * (N + 1) # 到着時刻

def dfs(G,s):
    global time
    stack = deque([s])
    arrive_time[s] = time
    while stack:
        t = stack[-1]
        if G[t]:
            w = G[t].popleft()
            if arrive_time[w] >= 0:
                continue
            elif w in stack:
                continue
            else:
                time += 1
                arrive_time[w] = time
                stack.append(w)
        else:
            time += 1
            finish_time[t] = time
            stack.pop()
            
    return arrive_time,finish_time

for i in range(1,N+1):
    if arrive_time[i] < 0:
        arrive,finish = dfs(G,i)
        time += 1

for i, (a, f) in enumerate(zip(arrive,finish)):
    if not i == 0:
        print(i,a,f)

Python: import heapq
from collections import deque
from enum import Enum
import sys
import math
from _heapq import heappush, heappop

BIG_NUM = 2000000000
MOD = 1000000007
EPS = 0.000000001

global current_time
global visited,go_time,back_time
global G


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 = []
for i in range(n):
    a = list(map(int,input().split()))
    g.append(a[2:])
d = [0]*n
f = [0]*n
global t
t = 1
d[0] = 1
x = 1
def find(x):
    global t
    if len(g[x-1]) == 0:
        t += 1
        f[x-1] = t
    else:
        for i in g[x-1]:
            if d[i-1] == 0:
                t += 1
                d[i-1] = t
                find(i)
        t += 1
        f[x-1] = t

find(x)
for i in range(n):
    if d[i] == 0:
        t += 1
        d[i] = t
        find(i+1)
for i in range(n):
    print(i+1, d[i], f[i])