Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}
	}

	d := make([]int, n+1)
	f := make([]int, n+1)
	t := 1
	for i := 1; i <= n; i++ {
		t = dfs(&g, &d, &f, i, t)
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, d[i], f[i])
	}
}

func dfs(g *[][]int, d *[]int, f *[]int, id int, t int) int {
	if (*d)[id] > 0 {
		return t
	}
	(*d)[id] = t
	t += 1
	for i := 0; i < len((*g)[id]); i++ {
		t = dfs(g, d, f, (*g)[id][i], t)
	}
	(*f)[id] = t
	return t+1
}

Python: n = int(input())
graph = {}
ans = []
np = set(range(1,n+1))
for i in range(n):
    t = list(map(int, input().split()))
    v = t[0]
    k = t[1]
    graph[v] = [t[i+2] for i in range(k)]
    np=np - set(graph[v])
    ans.append([v,None,None])

class Time:
    def __init__(self):
        self.time = 0
    def getTime(self):
        self.time += 1
        return self.time

t = Time()

visited = set()
def dfs(graph, target):
    visited.add(target)
    # ???????????????????¨????
    if ans[target - 1][1] is None:
        ans[target - 1][1] = t.getTime()
    if graph[target] == []:
        if ans[target - 1][2] is None:
            ans[target - 1][2] = t.getTime()        
        return
    for v in sorted(graph[target]):
        # # ???????????????????¨????
        if v not in visited:        
            if ans[v - 1][1] is None:
                ans[v - 1][1] = t.getTime()        
            visited.add(target)
            dfs(graph,v)
    if ans[target - 1][2] is None:
        ans[target - 1][2] = t.getTime()

if np == set():
    np = [1]
for v in np:
    dfs(graph,v)
for row in ans:
    print(*row)

Python: n = int(input())
m = [[0 for j in range(n)] for i in range(n)]
color = [0 for i in range(n)]
d = [0 for i in range(n)]
f = [0 for i in range(n)]
time = [0]


def dfs(u):
    color[u] = 1
    time[0] += 1
    d[u] = time[0]
    for i in range(n):
        if m[u][i] == 1 and color[i] == 0:
            dfs(i)

    color[u] = 2
    time[0] += 1
    f[u] = time[0]


def main():
    for i in range(n):
        data = list(map(int, input().split()))
        for j in range(2, len(data)):
            m[data[0]-1][data[j]-1] = 1

    for i in range(n):
        if color[i] == 0:
            dfs(i)

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


if __name__ == '__main__':
    main()

Python: 
n = int(input())
g_list = {}
for _ in range(n):
    n1, num, *cl = map(int, input().split())
    g_list[n1] = cl


# 深さ優先探索: クラス使って書く？
class Graph():
    def __init__(self, g_list):
        self.time = 0
        self.nodes = {}
        self.d = {}
        self.f = {}
        self.g_list = g_list

    def dfs(self, node):
        self.time += 1
        self.d[node] = self.time
        for node_ in self.g_list[node]:
            if node_ not in self.d:
                self.dfs(node_)
        self.time += 1
        self.f[node] = self.time


g = Graph(g_list)
for i in range(1, n+1):
    if i not in g.d:
        g.dfs(i)

for g, f in zip(sorted(g.d.items()), sorted(g.f.items())):
    print(g[0], g[1], f[1])

Python: from sys import stdin

X = [ 0 for i in range(100) ]
d = [ 0 for i in range(100) ]
f = [ 0 for i in range(100) ]
G = [[ 0 for i in range(100) ] for i in range(100)]

t = 0

def DFS(i) :
	global t
	t += 1
	d[i] = t
	for j in range(n) :
		if G[i][j] != 0 and d[j] == 0 : DFS(j)
	t += 1
	f[i] = t


n = int(input())
for i in range(n) :
	X[i] = stdin.readline().strip().split()


for i in range(n) :
	for j in range(int(X[i][1])) :
		G[int(X[i][0])-1][int(X[i][j+2])-1] = 1

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

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

Python: # -*- coding: utf_8 -*-

level = False
def debug(v):
    if level:
        print(v)

n = int(input())
a = [0]

for i in range(n):
    v = input().split()
    v.pop(0)
    v.pop(0)
    a.append([int(x) for x in v])

debug(a)
stack = [1]
results = [[0 for i in range(2)] for j in range(n + 1)]
results[0][0] = 0
time = 0

def depth_first_search(a, stack):
    debug(a)
    debug(results)
    debug(stack)
    global time
    if len(stack) == 0:
        return

    v = stack.pop()
    if results[v][0] == 0:
        time += 1
        results[v][0] = time

    es = a[v]
    if len(es) == 0 and results[v][1] == 0:
        time += 1
        results[v][1] = time

    if len(es) != 0:
        stack.append(v)
        next_vert = es.pop(0)
        if results[next_vert][0] == 0:
            stack.append(next_vert)

    depth_first_search(a, stack)

for i in range(n):
    stack = [i + 1]
    depth_first_search(a, stack)

debug(results)

results.pop(0)

i = 1
for row in results:
    print(str(i) + " " + str(row[0]) + " " + str(row[1]))
    i += 1

Python: n=int(input())
E=[0]*n
for _ in range(n):
    u,k,*V=map(int,input().split())
    E[u-1]=sorted(V)[::-1]
todo=[1]
seen=[0]*n
d=[0]*n
f=[0]*n
t=0
while 0 in f:
    if not todo:
        todo.append(seen.index(0)+1)    
    if seen[todo[-1]-1]==0:
        seen[todo[-1]-1]=1
        t+=1
        d[todo[-1]-1]=t
        for v in E[todo[-1]-1]:
            if d[v-1]==0:
                todo.append(v)
    elif f[todo[-1]-1]==0:
        t+=1
        f[todo.pop()-1]=t
    else:
        todo.pop()
for i in range(n):
    print(i+1,d[i],f[i])

Python: n = int(input())
G = [[] for _ in range(n)]
u1 = 0
for _ in range(n):
    u, k, *v = [int(i) for i in input().split()]
    G[u - 1] = v
    if k != 0 and u1 == 0:
        u1 = u

time = 1
u = u1
D = []
F = []
out = [[i+1, 0, 0] for i in range(n)]
T = []
while True:
    if u not in D:
        out[u - 1][1] = time
        D.append(u)
        T.append(u)
    if G[u - 1] == [] or G[u - 1][0] in F:
        time += 1
        out[T.pop() - 1][2] = time
        F.append(u)
        if T == []:
            if len(D) == n:
                break
            else:
                for ni in range(n):
                    if ni + 1 not in D:
                        u = ni + 1
                        break
        else:
            u = T[-1]
    else:
        u = G[u - 1].pop(0)
        time += 1

for ni in range(n):
    print(*out[ni])