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: n=int(input())
g=[]
for i in range(n):
    u,k,*varray= map(int,input().split())
    g.append(varray)

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

def dfs(src):
    global time
    d[src]= time
    time+=1
    for i in g[src]:
        if d[i-1]== -1:
            dfs(i-1)
    f[src]= time
    time+=1

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

Python: N = int(input())
adj_list = [ [] for _ in range(N+1) ]
for _ in range(N):
  lst = list(map(int,input().split()))
  node = lst[0]
  if lst[1] != 0:
    adj_list[node] = lst[2:]


visited = [False] * (N+1)
arrived = [-1] * (N+1)
left = [-1] * (N+1)

time = 0
def dfs(node):
  global time

  arrived[node] = time
  visited[node] = True

  for nei in adj_list[node]:
    if not visited[nei]:
      time += 1
      dfs(nei)
  else:
    time += 1
    left[node] = time

for i in range(1, N+1):
  if not visited[i]:
    time += 1
    dfs(i)

for i in range(1, N+1):
  print(i, arrived[i], left[i])

Python: # coding: utf-8
def depth(i, adj, Dep, Arr, times):
    if Dep[i-1]:
        return times
    Dep[i-1]=times
    times+=1
    # t=[depth(j, adj, Dep, f, times) j in adj[i-1]]
    for j in adj[i-1]:
        times=depth(j, adj, Dep, Arr, times)
    Arr[i - 1]=times
    times+=1
    return times


n=int(input())
adj=[list(map(int, input().split()))[2:] for i in range(n)]

d,f=[0]*n,[0]*n

t=1

dlist=[i for i in range(n) if d[i]==0]

for i in dlist:
    t = depth(i + 1, adj, d, f, t)

for i, df in enumerate(zip(d, f)):
    print(i + 1, *df)

Python: def main():

    inf = 1000000007
    n = int(input())
    e = [[] for _ in range(n)]
    d = [inf]*n
    f = [inf]*n
    step = 1

    def dfs(v):
        nonlocal step
        d[v] = step
        step+=1
        for u in e[v]:
            if d[u] == inf:dfs(u)
        f[v] = step
        step +=1

    e = [[] for _ in range(n)]
    for i in range(n):
        m = list(map(int,input().split()))
        for j in range(2,len(m)):
            e[m[0]-1].append(m[j]-1)
    for i in range(n):
        if d[i]==inf:dfs(i)
    for i in range(n):
        print (i+1,d[i],f[i])

if __name__ == '__main__':
    main()

Python: import collections,sys
def I(): return int(sys.stdin.readline().rstrip())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
n = I()
ukv = [LI() for _ in range(n)]
graph = {i:collections.deque() for i in range(1,n+1)} #1_indexed
for x in ukv:
    u,k,*v = x
    for y in v:
        graph[u].append(y)
seen = [0]*(n+1) #1_indexed
stack = []
time = 0
seentime = [0]*(n+1) #1_indexed
donetime = [0]*(n+1) #1_indexed
def dfs(j):
    global time
    seen[j] = 1
    stack.append(j)
    time += 1
    seentime[j] = time
    while stack:
        s = stack[-1]
        if not graph[s]:
            stack.pop()
            time += 1
            donetime[s] = time
            continue
        g_NO = graph[s].popleft()
        if seen[g_NO]:
            continue
        seen[g_NO] = 1
        stack.append(g_NO)
        time += 1
        seentime[g_NO] = time
for j in range(1,n+1):
    if seen[j]:
        continue
    dfs(j)
for k,a,b in zip(range(1,n+1),seentime[1:],donetime[1:]):
    print(k,a,b)

Python: 
#graphの頂点vertex(インデックス、0オリジン)を深さ優先探索。dis_time:最初に訪れた時のtimeを管理するリスト
#fin_time:その頂点に対して、探索が終わった時のtimeを管理するリスト　tmp_time:現在のtime(関数内で変更できるようにリスト)
def DPS(graph,vertex,dis_time,fin_time,tmp_time):
    tmp_time[0]+=1
    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、
            DPS(graph,i,dis_time,fin_time,tmp_time)
    
    tmp_time[0]+=1
    fin_time[vertex]=tmp_time[0]



#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=[0]
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: def main():
    num = int(input())
    Dst = [None for i in range(num + 1)]
    Fst = [0] * (num + 1)
    Lst = Fst[:]
    S = []

    for n in range(1, num+1):
        a = list(map(int,input().split()))
        u = a[0]
        if a[1] > 0:
            Dst[u] = a[2:]
            Dst[u].reverse()

    cnt = 1
    S.append(1)
    Fst[1] = 1
    while(len(S) > 0):
        cnt += 1
        u = S.pop()
        if Dst[u] is not None and len(Dst[u]) > 0:
            u1 = Dst[u].pop()
            if Fst[u1] == 0:
                S.append(u)
                S.append(u1)
                Fst[u1] = cnt
            else:
                Lst[u] = cnt
        else:
            Lst[u] = cnt

    for n in range(1, num+1):
        print("{} {} {}".format(n,Fst[n],Lst[n]))

if __name__ == '__main__':
    main()