Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve(parseProblem())
}

type graph struct {
	size  int
	edges [][]int
}

func parseProblem() *graph {
	n := scanInt(sc)
	g := &graph{
		size:  n,
		edges: make([][]int, n),
	}
	for i := 0; i < g.size; i++ {
		_ = scanInt(sc)
		k := scanInt(sc)
		g.edges[i] = make([]int, k)
		for j := 0; j < k; j++ {
			g.edges[i][j] = scanInt(sc) - 1
		}
	}
	return g
}

func resolve(g *graph) {
	ds := make([]int, g.size)
	fs := make([]int, g.size)
	time := 0
	for i := 0; i < len(ds); i++ {
		if ds[i] == 0 {
			time++
			time = _dfs(ds, fs, time, g, i)
		}
	}
	for i := 0; i < len(ds); i++ {
		fmt.Println(i+1, ds[i], fs[i])
	}
	return
}

func _dfs(ds, fs []int, time int, g *graph, idx int) int {
	ds[idx] = time
	for _, next := range g.edges[idx] {
		if ds[next] > 0 {
			continue
		}
		time++
		time = _dfs(ds, fs, time, g, next)
	}
	time++
	fs[idx] = time
	return time
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

Python: j = 1
def dfs(graph, start, result, visited=None):
    global j
    if visited == None:
        visited = []
    visited.append(start)
    result[start][1]  = j
    for next in graph[start][2:]:
        if next in visited:
            continue
        j += 1
        dfs(graph, next, result, visited)
    else:
        j += 1
        result[start][2] = j

n = int(input())
g = [[]]
r = [[i,0,0] for i in range(n + 1)]

for i in range(n):
    g.append(list(map(int, input().split())))
dfs(g,1,r)
for i in range(1,n+1):
    print(*r[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+1, d, f)

Python: n = int(input())
Adj = [[0]]
for _ in range(n):
    Adj.append(list(map(int, input().split()))[2:])

visited = [False]*(n+1)
s = [0]*(n+1)
f = [0]*(n+1)
time = 0

def dfs(i):
    global time
    time += 1
    s[i] = time
    visited[i] = True
    for j in Adj[i]:
        if not visited[j]:
            dfs(j)
    time += 1
    f[i] = time

while not all(visited[1:]):
    i = visited[1:].index(False) + 1
    dfs(i)

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

Python: # -*- coding:utf-8 -*-

def solve():
    from collections import deque

    N = int(input())
    Us = [[] for _ in range(N)]

    for i in range(N):
        _in = list(map(int, input().split()))
        if len(_in) == 2:
            continue
        u, k, Vs = _in[0], _in[1], _in[2:]
        Vs.sort()
        for v in Vs:
            Us[u-1].append(v-1)
        Us[u-1] = deque(Us[u-1])

    find = [0 for _ in range(N)]  # 発見時刻
    terminated = [0 for _ in range(N)]  # 終了時刻
    tim = [0]  # 経過時間

    def dfs(now):
        while Us[now]:
            nxt = Us[now].popleft()

            if find[nxt] != 0:
                continue

            tim[0] += 1
            find[nxt] = tim[0]

            dfs(nxt)

        if terminated[now] == 0:
            tim[0] += 1
            terminated[now] = tim[0]

    for i in range(N):
        if find[i] == 0:
            tim[0] += 1
            find[i] = tim[0]
            dfs(i)

    for i in range(N):
        print(i+1, find[i], terminated[i])


if __name__ == "__main__":
    solve()

Python: # -*- coding: utf-8 -*-


class Graph:
    def __init__(self, n, adj_matrix):
        self.n = n
        self.adj_matrix = adj_matrix

    def show(self):
        for _ in self.adj_matrix:
            print(*_)

    def dfs(self):
        self.states = [2] * self.n
        self.d = [None] * self.n
        self.f = [None] * self.n
        self.time = 0

        for u in range(self.n):
            if self.states[u] == 2:
                self.dfs_visit(u)

    def dfs_visit(self, u):
        self.states[u] = 1
        self.time += 1
        self.d[u] = self.time

        for v, edge in enumerate(self.adj_matrix[u]):
            if edge and self.states[v] == 2:
                self.dfs_visit(v)

        self.states[u] = 0
        self.time += 1
        self.f[u] = self.time

    def show_dfs(self, start=0):
        self.dfs()
        for i, (d, f) in enumerate(zip(self.d, self.f)):
            print(i + 1, d, f)


if __name__ == '__main__':
    n = int(input())
    adj_matrix = [[0] * n for i in range(n)]
    for i in range(n):
        for v in input().split()[2:]:
            adj_matrix[i][int(v) - 1] = 1

    g = Graph(n, adj_matrix)
    g.show_dfs()

Python: def dfs():
    tt = 0
    for u in range(N):
        if colors[u] == WHITE:
            tt = dfs_visit(u, tt)

def dfs_visit(u, tt):
    tt += 1
    colors[u] = GLAY
    d[u] = tt
    for v in range(N):
        if adjacency_list[u][v] == 1 and colors[v] == WHITE:
            tt = dfs_visit(v, tt)
    tt += 1
    colors[u] = BLACK
    f[u] = tt
    return tt


N = int(input())
adjacency_list = [[0 for j in range(N)] for i in range(N)]
for _ in range(N):
    u, k, *v = map(int, input().split())
    for i in v:
        adjacency_list[u-1][i-1] = 1

WHITE = 0
GLAY = 1
BLACK = 2
colors = [WHITE for _ in range(N)]
d = [0 for _ in range(N)]
f = [0 for _ in range(N)]

dfs()

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

Python: n=int(input())

l=[[0 for i in range(n)] for j in range(n)]##静的確保 隣接行列
d=[0 for i in range(n)]##発見
f=[0 for i in range(n)]##完了
stack=[]##スタック
check=[]

for i in range(n):
    p=[int(x) for x in input().split()]
    
    for j in range(n):
        if j+1 in p[2:]:
            l[i][j]=1
##print("---隣接行列---")
##print(l)

time=1


while len(check)<n:
    for i in range(n):
        if i+1 not in check:
            stack+=[i+1]
            d[i]=time
            break
        else: pass

    while len(stack)!=0:
        ##print("----------while---------")
        for i in range(n):
            if l[stack[-1]-1][i]==1 and not i+1 in check and stack[-1]-1!=i:
                time+=1
                d[i]=time
                stack+=[i+1]

               ## print("stack:",stack)
               ## print("check:",check)
               ## print("d[",i,"]:",d[i])
                break
            elif i==n-1:
##最深    
                check+=[stack[-1]]
                time+=1
                f[stack.pop()-1]=time

               ## print("f[",i,"]:",f[i])
               ## print("check:",check)
    time+=1


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

Python: import sys
sys.setrecursionlimit(10**9)
from collections import deque

n = int(input())
u = [[] for i in range(n+1)] #隣接リスト
for i in range(n):
    v = list(map(int, input().split()))
    u[v[0]] = v[1:] #v = [次数, 頂点...]

d = [-1] * (n+1)
f = [-1] * (n+1)
visited = [False] * (n+1)
visited[0] = True
time = 1

#再帰
def dfs(c):
    global time
    d[c] = time
    time += 1
    visited[c] = True
    for i in range(1, u[c][0]+1):
        if not visited[u[c][i]]:
            dfs(u[c][i])
    f[c] = time
    time += 1
"""
探索は元の始点から到達可能なすべての頂点を発見するまで続き、
未発見の頂点が残っていれば、
その中の番号が一番小さい１つを新たな始点として探索を続けます。
"""
while False in visited:
    dfs(visited.index(False))

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