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)
	}
}

C++: #include<iostream>
#include<stack>
using namespace std;

#define S 100
#define BLACK 2
#define WHITE 0
#define GRAY 1

int n,a[S][S];
int cnd[S],d[S],f[S],T=0;
int nt[S];

int next(int u){
    for(int v=nt[u];v<n;v++){
        nt[u]=v+1;
        if(a[u][v])return v;
    }
    return -1;
}

void visit(int r){
    for(int i=0;i<n;i++)nt[i]=0;
    stack<int>st;
    st.push(r);
    cnd[r]=GRAY;
    d[r]=++T;

    while(!st.empty()){
        int u=st.top();
        int v=next(u);
        if(v!=-1){
            if(cnd[v]==WHITE){
                cnd[v]=GRAY;
                d[v]=++T;
                st.push(v);
            }
        }else{
            st.pop();
            cnd[u]=BLACK;
            f[u]=++T;
        }
    }
}

void outp(){
    for(int i=0;i<n;i++){
        cnd[i]=WHITE;
        //nt[i]=0;
    }

    for(int j=0;j<n;j++){
        if(cnd[j]==WHITE)visit(j);
    }
    for(int k=0;k<n;k++){
        cout<<k+1<<" "<<d[k]<<" "<<f[k]<<endl;
    }
}

int main(){
    int u,k,J,i,j;
    cin>>n;
    for(i=0;i<n;i++){
        for(j=0;j<n;j++)a[i][j]=0;
    }
    for(i=0;i<n;i++){
        cin>>u>>k;
        for(j=0;j<k;j++){
            cin>>J;
            a[u-1][J-1]=1;
        }
    }
    outp();
    return 0;
}

C++: #include <algorithm>
#include <iostream>
using namespace std;

int t=0,k,n;
int gone[100+10]={},before[100+10]={},a[100+10][100+10]={};

void dfs(int cur){
    if(gone[cur]!=1){
        t+=1;
        cerr << "visiting " << cur << " at " << t << endl;
        gone[cur]=1;
    }
    for(int m=1;m<=n;m++){
        if(a[cur][m]==1){
            if(gone[m]==0){
                dfs(m);
            }
        }
    }
    t+=1;
    cerr << "complete " << cur << " at " << t << endl;
}

int main(){
    cin >> n;
    for(int i=1;i<=n;i++){
        int u,p;
        cin >> u >> k;
        for(int j=0;j<k;j++){
            cin >> p;
            a[i][p]=1;
        }
    }
    for(int q=1;q<=n;q++){
        if(gone[q]!=1) dfs(q);
    }
}

C++: #include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for(int i = int(a); i < int(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
const long long INFLL = 1LL << 60;
const int INFINT = 1 << 30;
const long long MOD = 1e9 + 7;

vector<vector<int>> G(101, vector<int>(0));
vector<int> c(101, 0);
vector<int> d(101, 0);
vector<int> f(101, 0);

template <class T> void vecout(T V) {
    auto t = V.begin();
    *t++;
    while(t != V.end()) {
        cout << " " << *t++;
        // if(t != V.end()) cout << " ";
    }
    cout << endl;
};

int t = 0;
void dfs(int i) {
    if(c[i]) return;
    c[i] = 1;
    d[i] = ++t;
    for(auto e : G[i])
        dfs(e);
    f[i] = ++t;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, a, b, c;
    cin >> n;
    rep(i, n) {
        cin >> a >> b;
        rep(j, b) {
            cin >> c;
            G[a].push_back(c);
        }
    }
    rep(i, 1, n + 1) dfs(i);

    rep(i, 1, n + 1) cout << i << " " << d[i] << " " << f[i] << "\n";
}

C++: 	#include<stdio.h>
	int k[101]={0},d[101]={},f[101]={};
	int v[101][101]={0};
	int cur;
	void dfs(int id){
		if(d[id]!=0){
			return;
			}
			cur++;
			if(d[id]==0){
				d[id]=cur;
			}
			for(int i=0;i<k[id];i++){
				dfs(v[id][i]);
			}
			cur++;
			f[id]=cur;
			return;
		}
		int main(void){
		int n=0,u=0;
		scanf("%d",&n);
		for(int i=0;i<n;i++){
			scanf("%d",&u);
			scanf("%d",&k[u]);
			for(int j=0;j<k[u];j++){
				scanf("%d",&v[u][j]);//uからいけるj個目のノードがv[u][j]
			}
		}
		for(int i=1;i<n;i++){
		if(d[i]==0){
		dfs(i);
		}
		}
		for(int i=1;i<=n;i++){
			printf("%d %d %d\n",i,d[i],f[i]);
		}
	return(0);
}