Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

Python: # -*- coding: utf-8 -*-
# 標準入力を取得
n = int(input())
G = {}
for _ in range(n):
    g = list(map(int, input().split()))
    G[g[0]] = g[2:]

# 求解処理
seen = [False for _ in range(n)]
ans = []


def dfs(v: int) -> None:
    seen[v - 1] = True
    ans.append(v)

    for w in G[v]:
        if not seen[w - 1]:
            dfs(w)

    ans.append(v)


while sum(seen) != n:
    v = seen.index(False)
    dfs(v + 1)

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

for i, a in enumerate(ans):
    if d[a - 1] == -1:
        d[a - 1] = i + 1
    else:
        f[a - 1] = i + 1

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

Python: # coding=utf-8

n = int(input())
first_v = 0
time = 0
L = []
d = [None for _ in range(n)]
f = [None for _ in range(n)]
stuck = []
for _ in range(n):
    u, k, *v = map(int, input().split())
    L.append(list(map(lambda x: x-1, v)))

v = first_v #??¢?´¢????????????
while True:
    """print("------------------------------")
    print("stuck:", *stuck)
    print("L:", L)
    print("d:", *d)
    print("f:", *f)
    print("time:", time)
    print("v:", v)"""
    if len(L[v]) > 0:
        stuck.append(v)
        if not d[v]:
            time += 1
            d[v] = time
        v = L[v].pop(0)
    elif len(stuck) > 0:
        if not d[v]:
            time += 1
            d[v] = time
        if not f[v]:
            time += 1
            f[v] = time
        v = stuck.pop(-1)
    else:
        time += 1
        f[first_v] = time
        if None in d:
            first_v = d.index(None)
            v = first_v
        else:
            break

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

Python: # coding: UTF-8
from collections import deque
n = int(input())
arrow = {}
visited = set()
d = {}
f = {}


for i in range(n):
  raw = list(map(int,input().split()))
  #print(raw)
  u = raw.pop(0)
  k = raw.pop(0)
  raw.sort()
  q = deque(raw)
  arrow[u] = q
  d[u] = -1
  f[u] = -1

def dfslocal(v,t,arrow,f,d):
  t += 1
  d[v] = t
  visited.add(v)
  #print("First visit to " + str(v) + " at " + str(t) + "!")
  while arrow[v]:
    k = arrow[v].popleft()
    if k not in visited:
      
      t = dfslocal(k,t,arrow,f,d)
  f[v] = t+1
  return t+1

def dfsglobal(arrow,f,d):
  t = 0
  for u in range(n):
    if u+1 not in visited:
      t = dfslocal(u+1,t,arrow,f,d)
  return t

t = dfsglobal(arrow,f,d)

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

Python: def dfs(n):
    global t
    S[n] = t
    DP[n]=1
    for i in A[n][2:]:
        if not DP[i]:
            t += 1
            dfs(i)
    t += 1
    F[n] = t
n = int(input())
d = deque()
A = [0]*(n+1)
S = [0]*(n+1)
F = [0]*(n+1)
DP = [0]*(n+1)
for i in range(n):
    A[i+1] = [int(i) for i in input().split()]
t = 1
dfs(1)
for i in range(1,n+1):
    tmp = "{} {} {}".format(i,S[i],F[i])
    print(tmp)

Python: import sys
sys.setrecursionlimit(10**6)
input = sys.stdin.readline

global time
time = 0

def dfs(u: int, visited: list, d: list, f: list, M: list, n: int):
    global time
    visited[u] = True
    time += 1
    d[u] = time
    for j in range(n):
        if M[u][j] == 1 and not visited[j]:
            dfs(j, visited, d, f, M, n)
    time += 1
    f[u] += time

def main():
    n = int(input())
    visited = [False] * n
    M = [[0]*n for _ in range(n)]
    for _ in range(n):
        a = list(map(int, input().split()))
        for i in range(a[1]):
            M[a[0]-1][a[i+2]-1] = 1
    d = [0] * n
    f = [0] * n
    for i in range(n):
        if not visited[i]:
            dfs(i, visited, d, f, M, n)
    for i in range(n):
        print(i+1, d[i], f[i])

if __name__ == '__main__': main()

Python: n = int(input())
a = [[0]*n for i in range(n)]
  
for i in range(n):
    v = list(map(int, input().split()))
    u = v[0]
    k = v[1]
    for j in range(k):
        a[u - 1][v[2 + j] - 1] = 1

d = [0] * n
f = [0] * n
isDiscovered = [False] * n
time_stamp = 0

def dfs(x):
    global time_stamp
    isDiscovered [x] = True
    time_stamp = time_stamp + 1
    d[x] = time_stamp
    for i in range(n):
        if a[x][i] == 1 and isDiscovered[i] == False:
            dfs(i)
    time_stamp = time_stamp + 1
    f[x] = time_stamp

for i in range(n):
    if isDiscovered[i] == False:
        dfs(i)

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

Python: #連結グラフではない
n = int(input())
V = [[] for _ in range(n+1)]
for _ in range(n):
    inpt = list(map(int,input().split( )))
    if len(inpt)>2:
        V[inpt[0]] = inpt[2:]


D = [0]*(n+1)
F = [0]*(n+1)

time = 1
Q = [1]
D[0] = -1
D[1] = 1
while len(Q) > 0 or 0 in D[1:]:
    v = Q[-1]
    remains = False
    for i in V[v]:
        if D[i] == 0:
            D[i] = time+1
            Q.append(i)
            remains = True
            break
    if not remains:
        F[v] = time+1
        Q.pop()
        
    time += 1
    if len(Q) == 0:
        if 0 in D:
            time += 1
            nxt = D.index(0)
            Q.append(nxt)
            D[nxt] = time
        else:
            pass
        

for i in range(1,n+1):
    print(i,D[i],F[i])