Go: package main

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

// repr state of visited node
// WHITE yet visit
// GEAY  visiting
// BLACK visited
const (
	WHITE int = iota
	GRAY
	BLACK
)

type dfsGraph struct {
	g      [][]int
	colors []int
	stime  []int // Start time of visiting node
	ftime  []int // Finish time of visiting node
}

var time int

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func (dg dfsGraph) dfsVisit(u int) {
	// 頂点uを訪問中に設定
	dg.colors[u] = GRAY
	time++
	dg.stime[u] = time

	// uの隣接nodeを訪問
	for v := 0; v < len(dg.g); v++ {
		if dg.g[u][v] == 0 {
			continue // 辺がなければスキップ
		}

		// vが未訪問なら訪問
		if dg.colors[v] == WHITE {
			dg.dfsVisit(v)
		}
	}

	// 頂点uを訪問済みに設定
	dg.colors[u] = BLACK
	time++
	dg.ftime[u] = time
}

func (dg dfsGraph) dfs() {
	for i := 0; i < len(dg.g); i++ {
		if dg.colors[i] == WHITE {
			dg.dfsVisit(i)
		}
	}
}

func (dg dfsGraph) printDfsTime() {
	for i := 0; i < len(dg.g); i++ {
		fmt.Printf("%d %d %d\n", i+1, dg.stime[i], dg.ftime[i])
	}
}

func main() {
	adj := makeAdjList()
	colors := make([]int, len(adj))
	stime := make([]int, len(adj))
	ftime := make([]int, len(adj))
	graph := dfsGraph{adj, colors, stime, ftime}
	graph.dfs()
	graph.printDfsTime()
}

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])

Python: d_num = int(input())

graph = [[] for _ in range(d_num+1)]
for _ in range(d_num):
    u, k, *neighbors = map(int, input().split())
    graph[u] = neighbors

visited = set()
timestamps = [None for _ in range(d_num+1)]

def dfs(u, stmp):
    visited.add(u)
    entry = stmp

    stmp += 1
    for v in graph[u]:
        if v not in visited:
            stmp = dfs(v, stmp)

    timestamps[u] = entry, stmp
    return stmp+1

stmp = 1
for v in range(1, d_num+1):
    if v not in visited:
        stmp = dfs(v, stmp)

for num, (entry, leave) in enumerate(timestamps[1:], 1):
    print(num, entry, leave)

Python: import sys, math
from itertools import permutations, combinations, accumulate
from collections import defaultdict, Counter, deque
from math import factorial#, gcd
from bisect import bisect_left #bisect_left(list, value)
sys.setrecursionlimit(10**7)
enu = enumerate
MOD = 10**9+7
def input(): return sys.stdin.readline()[:-1]
def pri(x): print('\n'.join(map(str, x)))

N = int(input())
G = [list(map(int, input().split())) for _ in range(N)]
c = [0]*N # 0:not found, 1:found, 2:finished
res = [[0]*2 for _ in range(N)]

time = 1
def dfs(index):
#    print('index:', index)
    global time
    if c[index]==0:
        c[index]=1
        res[index][0] = time # found
        time += 1
    elif c[index]==1:
        return
    elif c[index]==2:
        return

    u, k, *v = G[index]
    for node in v:
        dfs(node-1) # 1-index -> 0-index

    c[index] = 2
    res[index][1] = time # finished
    time += 1
    return

for i in range(N):
    dfs(i)
res = [[val1]+val2 for val1, val2 in zip(list(range(1, N+1)), res)]
for val in res:
    print(*val)

Python: n=int(input())
t=1
a=[[0 for i in range(n)]for j in range(n)]
t1=[0 for i in range(n)]
t2=[0 for i in range(n)]
s=[]
c=[]
s.append(0)
t1[0]=t
t+=1
for i in range(n):
    p=[int(x) for x in input().split()]
    for j in range(n):
        if j+1 in p[2:]:
            a[i][j]=1

i=0
while len(c)!=n:
    if 1 not in a[i][0:]:
        if i not in c:
            t2[i]=t
            t+=1
            c.append(i)
            del s[-1]
            if len(s)>0:
                i=s[-1]
    for j in range(n):
        if a[i][j]==1:
            a[i][j]=0
            if j not in c:
                s.append(j)
                i=j
                t1[i]=t
                t+=1
            break

for i in range(n):
    print(i+1,t1[i],t2[i])

Python: def dfs(v):
    global t, d, f, visited
    d[v] = t
    visited[v] = True
    t += 1
    for u in AL[v]:
        if not visited[u]:
            dfs(u)
    f[v] = t
    t += 1

# 入力
n = int(input())
AL = [[] for _ in range(n + 1)]
for v in range(1, n + 1):
    AL[v] = [int(x) for x in input().split()][2:]

# 計算
d = [0] * (n + 1)
f = [0] * (n + 1)
t = 1
visited = [False] * (n + 1)
for v in range(1, n + 1):
    if not visited[v]:
        dfs(v)

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