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: def DPS(graph,vertex,dis_time,fin_time,tmp_time):
    dis_time[vertex]=tmp_time[0]
    for i in range(len(graph[0])):
        if(graph[vertex][i] !=0 and dis_time[i]==0):#枝先の頂点が探索済みでなかったら、
            tmp_time[0]+=1
            DPS(graph,i,dis_time,fin_time,tmp_time)
    
    if(dis_time[vertex]==tmp_time[0]):#vertexから、どの頂点に対しても調査が進まなかったら
        tmp_time[0]+=1
    fin_time[vertex]=tmp_time[0]
    tmp_time[0]+=1



#グラフの作成
n=int(input())
graph=[[0]*n for loop in range(n)]
for loop in range(n):
    tmp_ope=list(map(int,input().split()))
    for j in range(tmp_ope[1]):
        graph[tmp_ope[0]-1][tmp_ope[j+2]-1]=1


dis_time=[0]*n
fin_time=[0]*n
tmp_time=[1]
for i in range(n):
    if(dis_time[i]==0):
        DPS(graph,i,dis_time,fin_time,tmp_time)

for i in range(n):
    print(f"{i+1} {dis_time[i]} {fin_time[i]}")

Python: cnt = 1
def dep(G,s_cnt,f_cnt,np):
    global cnt
    s_cnt[np] = cnt
    cnt += 1
    for i in range(n):
        if G[np][i] == 1 and s_cnt[i] == 0:
            dep(G,s_cnt,f_cnt,i)
    f_cnt[np] = cnt
    cnt += 1
    

n = int(input())
G = [[0 for i in range(n)] for j in range(n)]
s_cnt = [0 for i in range(n)]
f_cnt = [0 for i in range(n)]

for i in range(n):
    S = list(map(int, input().split()))
    tmp_n = S[1]
    for j in range(tmp_n):
        G[i][S[j+2]-1] = 1
        
for i in range(n):
    if s_cnt[i]==0:
        dep(G,s_cnt,f_cnt,i)

for i in range(n):
    print(i+1,s_cnt[i],f_cnt[i])

Python: n = int(input())
graph = [[] for _ in range(n)]
for i in range(n):
    in_list = list(map(int, input().split()))
    u = in_list[0]
    graph[u - 1] = in_list[2:]

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


def dfs(now, prev, graph, d, f):
    global time
    time += 1
    d[now] = time
    if not graph[now]:
        f[now] = time + 1
        time += 1
        return
    for k in graph[now]:
        if k - 1 == prev or d[k-1] !=0:
            continue
        dfs(k - 1, now, graph, d, f)
    else:
        time += 1
        f[now] = time
    return d, f


d, f = dfs(0, 0, graph, d, f)
for i in range(1, n + 1):
    print(i, d[i - 1], f[i - 1])

Python: from collections import defaultdict as dd

N = int(input())
graph = dd(list)
seen = dd(int)
u = []
d, f = dd(int), dd(int)
ts = 1
for _ in range(N):
  info = list(map(int, input().split()))
  u.append(info[0])
  graph[info[0]] = info[2:]

def dfs(v):
  global ts
  d[v] = ts
  ts += 1
  
  seen[v] = 1
  for next_v in graph[v]:
    if seen[next_v]:
      continue
    dfs(next_v)
  
  f[v] = ts
  ts += 1

for key in u:
  if seen[key]:
    continue
  dfs(key)

for id in u:
  print("{} {} {}".format(id, d[id], f[id]))

Python: def dfs(v, time_, d, f, dp):
    if d[v] == 0:
        d[v] = time_
    for i in range(len(dp[v])):
        if d[dp[v][i]] == 0:
            time_ = dfs(dp[v][i], time_ + 1, d, f, dp)
    f[v] = time_ + 1
    return time_ +  1


def main():
    N = int(input())
    dp = [[] for i in range(N)]
    for i in range(N):
        line = [int(k) for k in input().split()]
        for j in range(len(line)):
            if j == 0 or j == 1:
                continue
            dp[line[0] - 1].append(line[j] - 1)

    d = [0] * N
    f = [0] * N
    time_ = 1
    for i in range(N):
        if d[i] == 0:
            time_ = dfs(i, time_, d, f, dp)
            time_ += 1
    for i in range(N):
        print(i + 1, d[i], f[i])

if __name__ == '__main__':
    main()

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

Python: # 隣接リスト
n = int(input())

graph = []
for _ in range(n):
    tmp = list(map(int, input().split()))
    if tmp[1] == 0:
        graph.append([])
    else:
        graph.append(tmp[2:])

#print(graph)
check = [0]*n
count = 0
go = [0]*n
back = [0]*n

def dfs(v):
    #print(v)
    global count
    if check[v] == 0:
        check[v] = 1
        count += 1
        go[v] = count
        tolist = graph[v]
        if len(tolist) > 0:
            for i in tolist:
                dfs(i-1)
        count += 1
        back[v] = count

while True:
    if 0 in check:
        k = check.index(0)
        dfs(k)
    else:
        break

#print("check\t:{}".format(check))
#print("go\t:{}".format(go))
#print("back\t:{}".format(back))

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

Python: n = int(input())
g = [[] for _ in range(n+1)] #1-index
for i in range(n):
    u, k, *v = map(int, input().split())
    for j in v:
        g[u].append(j)

#-------------------------------------------
def dfs(v): #未訪問の点vから潜っていく
    global time
    seen[v] = 1 #訪問済にする
    time += 1
    d[v] = time
    if g[v]:
        for next_v in g[v]:
            if seen[next_v] == 1: continue
            dfs(next_v) #再帰
    
    time += 1
    f[v] = time
    
#-------------------------------------------
seen = [0]*(n+1) #1-index
seen[0] = 1
seen[1] = 1 
d = [0]*(n+1)
f = [0]*(n+1)
time = 0

dfs(1) #深堀り

for i in range(1,n+1): #孤立点対応
    if seen[i] == 0:
        dfs(i)

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