Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

Python: N = int(input())
DG={}  # それぞれのnodeが持つ隣接リストを、キーをnodeにして管理
node_ls=[]
is_visited={}  # 訪れたかどうかを、nodeをキーに辞書で管理


# 有向グラフをディクトで管理することにする
for _ in range(N):
    tmp = input().split()
    node_id = tmp[0]
    node_ls.append(node_id)      # 1~n の順番
    is_visited[node_id] = False  # 訪れた時にTrueにする
    adj_num = int(tmp[1])    # 次数（隣接リストの数）
    if adj_num != 0:
        DG[node_id] = tmp[2:]  # 隣接リストを入れる
    else:
        DG[node_id] = []


d = {} # 発見した時刻を、nodeをキーにして保存する
f = {} # 隣接リストを調べ終えた時刻を、nodeをキーにして保存する
t = 1

def dfs(node):
    global t
    if is_visited[node]:  # 既に訪れていた場合
        return
    is_visited[node] = True
    d[node] = t # 訪れた時刻を入れる
    t += 1
    
    for no in DG[node]:
        dfs(no)
        
    f[node]=t # 隣接リストを全て調べ終えた時刻を入れる
    t += 1
    
for node in node_ls:  # 1~n の順番
    dfs(node)
    
for node in node_ls:
    print(node, d[node], f[node])

Python: import sys

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

time = 0

def dfs(u, adj, d, f, sumi):
    global time
    time += 1
    d[u] = time

    for v in adj[u]:
        if v not in sumi:
            dfs(v, adj, d, f, sumi)
        sumi.add(v)

    time += 1

    f[u] = time


def solve():
    n = int(input())
    adj = [None] * n

    for i in range(n):
        u, k, *vs = [int(j) - 1 for j in input().split()]
        # debug(vs, locals())
        adj[u] = vs

    # debug(adj, locals())
    
    d = [0] * n
    f = [0] * n
    sumi = {0}

    dfs(0, adj, d, f, sumi)

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

    pass

if __name__ == '__main__':
    solve()

Python: #coding: utf-8

n = int(input())
color = ["white" for i in range(n)]
d = [[] for i in range(n)]
global t
t = 0
M = [[False for i in range(n)] for j in range(n)]
for i in range(n):
    data = list(map(int,input().split()))
    u = data[0]
    k = data[1]
    if i == 0:
        start = u
    for v in data[2:2+k]:
        M[u-1][v-1] = True


def search(u,t):
    t += 1
    color[u-1] = "gray"
    d[u-1].append(t)
    for v in range(n):
        if M[u-1][v-1] and color[v-1] == "white":
            t = search(v,t)
    color[u-1] = "black"
    t += 1
    d[u-1].append(t)
    return t

t = search(start, t)
for i in range(1,n+1):
    if color[i-1] == "white":
        t = search(i, t)

for i in range(n):
    print(i+1, d[i][0], d[i][1])

Python: 
# ??±???????????¢?´¢(Depth First Search)

def DFS(n = 1, A = [0], i = 0, d = [0], f = [0], time = 1):
    for j in range(n):
        if A[i][j] == 1 and d[j] == 0:
            time = time + 1
            d[j] = time
            DFS(n, A, j, d, f, time)
    time = time + 1
    f[i] = time

n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = [0] * n

for i in range(n):
    value = map(int, raw_input().split())
    u = value[0] - 1
    k = value[1]
    nodes = value[2:]
    for i in range(k):
        v = nodes[i] - 1
        A[u][v] = 1

d = [0] * n
f = [0] * n
time = 1
d[0] = time
DFS(n, A, 0, d, f, time)

for i in range(n):
    print(str(i + 1) + " " + str(d[0]) + " " + str(f[0]))

Python: def dfs(v,t):
    d[v]=t
    t+=1
    for i in edge[v]:
        if d[i]==-1:
            t=dfs(i,t)
    f[v]=t
    t+=1
    return t

n=int(input())
edge=[[] for _ in range(n)]
for _ in range(n):
    u,_,*v=map(lambda x:int(x)-1,input().split())
    edge[u]=sorted(v)
d,f=[-1]*n,[-1]*n
k=1
for i in range(n):
    if d[i]==-1:
        k=dfs(i,k)
for i in range(n):
    print(i+1,d[i],f[i])

Python: from sys import stdin

d_num = int(stdin.readline().strip())

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

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: N = int(input())

E = [None] * (N+1)
for _ in range(N):
    u, k, *vs = list(map(int, input().split()))
    E[u] = vs

d = [0] * (N+1)
f = [0] * (N+1)
t = 0

def dfs(v):
    global t, d, f
    if d[v]:
        return
    t += 1
    d[v] = t
    for u in E[v]:
        dfs(u)
    t += 1
    f[v] = t

for v in range(1, N+1):
    dfs(v)

for v in range(1, N+1):
    print(v, d[v], f[v])

Python: import sys

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

time = 0

def dfs(u, adj, d, f, sumi):
    global time
    sumi.add(u)
    time += 1
    d[u] = time

    for v in adj[u]:
        if v not in sumi:
            dfs(v, adj, d, f, sumi)
            
    time += 1

    f[u] = time


def solve():
    n = int(input())
    adj = [None] * n

    for i in range(n):
        u, k, *vs = [int(j) - 1 for j in input().split()]
        # debug(vs, locals())
        adj[u] = vs

    # debug(adj, locals())
    
    d = [0] * n
    f = [0] * n
    sumi = {0}
    mitan = set(range(1, n))

    dfs(0, adj, d, f, sumi)
    mitan -= sumi
    # debug(mitan, locals())

    
    while mitan:
        u = min(mitan)
        dfs(u, adj, d, f, sumi)
        mitan -= sumi
        # debug(mitan, locals())
        

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

    pass

if __name__ == '__main__':
    solve()

Python: n = int(input())
graph = [[0 for i in range(n)] for j in range(n)]
d = [0] * n
f = [0] * n
g = [0] * n

time = 0

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

def search(i):
    global time
    time = time + 1
    d[i] = time
    g[i] = 1
    for j in range(i, n):
        if (graph[i][j] == 1) & (g[j] == 0):
            search(j)
    time = time + 1
    f[i] = time


search(0)
[print(i+1, d[i], f[i]) for i in range(n)]