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 <vector>
#include <algorithm>
#include <numeric>
#include <queue>
#include <stack>
#include <map>
#define FOR(i,b,e) for(int i=b;i<e;i++)
#define REP(i,n) FOR(i,0,n)
using namespace std;

const int N = 100;
int n;
int d[N+1], f[N+1], state[N+1], ns[N+1][N+1];
stack<int> s;

int next(int u) {
  FOR(i, 1, n+1) {
    if (ns[u][i] == 1 && state[i] == 0) return i;
  }
  return -1;
}
int main() {
	cin.tie(0);
 	ios::sync_with_stdio(false);

  cin >> n;

  FOR(i, 1, n+1) state[i] = 0;
  FOR(i, 1, n+1) {
    FOR(j, 1, n+1) {
      ns[i][j] = 0;
    }
  }

  REP(i, n) {
    int p, m;
    cin >> p; cin >> m;

    REP(j, m) {
      int pp; cin >> pp;
      ns[p][pp] = 1;
    }
  }

  int t = 1;

  s.push(1);
  state[1] = 1;
  d[1] = 1;
  while (!s.empty()) {
    t++;

    int p, np;
    p = s.top();
    if ((np = next(p)) != -1) {
      s.push(np);
      state[np] = 1;
      d[np] = t;
    } else {
      s.pop();
      state[p] = 2;
      f[p] = t;
    }
  }

  FOR(i, 1, n+1) {
    cout << i << " " << d[i] << " " << f[i] << endl;
  }
}

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

#define N 101

void DepthFirstSearch();

class stack{
public:
    int array[100];
    int top = -1;
    
    void push(int v) {
        top++;
        array[top] = v;
        return;
    }
    
    int pop() {
        top--;
        return array[top+1];
    }
    
    int show() {
        return array[top];
    }
};

typedef struct {
    int d;
    int f;
} P;

int n;
int t = 0;
int a[N][N] = {};
stack s;
P list[N];

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    cin>>n;
    
    int u, k, v;
    for(int i = 0; i < n; i++) {
        cin>>u>>k;
        
        for(int j = 0; j < k; j++) {
            cin>>v;
            a[u][v] = 1;
        }
    }
    
    for(int i = 1; i <= n; i++) {
        if(list[i].d == 0) {
            s.push(i);
            for(int j = 1; j <= n; j++) a[j][i] = 0;
            DepthFirstSearch();
            s.pop();
        }
    }
    
    for(int i = 1; i <= n; i++) {
        cout<<i<<' '<<list[i].d<<' '<<list[i].f<<endl;
    }
    
    return 0;
}

void DepthFirstSearch() {
    t++;
    int u = s.show();
    list[u].d = t;
    for(int i = 1; i <= n; i++) {
        if( a[u][i] == 1 ) {
            s.push(i);
            a[u][i] = 0;
            for(int j = 1; j <= n; j++) a[j][i] = 0;
            DepthFirstSearch();
            s.pop();
        }
    }
    t++;
    list[u].f = t;
}

C++: #include<bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;
using msi = map<string, int>;
using mii = map<int, int>;
using psi = pair<string, int>;
using pii = pair<int, int>;
using vlai = valarray<int>;
#define rep(i,n) for(int i=0;i<n;i++)
#define range(i,s,n) for(int i=s;i<n;i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define fs first
#define sc second
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define INF 1E9
#define EPS 1E-9
#define MOD (ll)(1E9+7)
#define PI 3.1415926535897932384

template <class T>ostream &operator<<(std::ostream &o, const vector<T> &v)
{
	rep(i, v.size()) {
		o << (i > 0 ? " " : "") << v[i];
	}
	return o;
}
int n,t=0;
vvi a;
vi d;
vi f;

void Depth(int pos) {
	if (d[pos] == 0) {
		d[pos] = ++t;
	}
	rep(i, n) {
		if (a[pos][i] == 1) {
			Depth(i);
		}
	}
	if (f[pos] == 0) {
		f[pos] = ++t;
	}
}


int main() {
	cin >> n;
	a.resize(n, vi(n, 0));
	d.resize(n, 0);
	f.resize(n, 0);
	rep(i, n) {
		int num,m;
		cin >>num >>m;
		rep(i, m) {
			int tmp;
			cin >> tmp;
			a[num - 1][tmp - 1] = 1;
		}
	}
	Depth(0);
	rep(i, n) {
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
	}
}

C++: #include <iostream>
#include <vector>

using namespace std;

void dfs(int v,vector<vector<int>>& vertex, int d[], int f[]);

int cnt = 1;

int main(){
    int n;
    cin >> n;
    int num;
    int tmp2;
    int d[n] = {};
    int f[n] = {};
    vector<vector<int>> vertex;
    vector<int> tmp;
    for(int i=0;i<n;i++){
        cin >> num;
        cin >> num;
        for(int j=0;j<num;j++){
            cin >> tmp2;
            tmp.push_back(tmp2-1);
        }
        vertex.push_back(tmp);
        tmp.clear();
    }
    dfs(0, vertex, d, f);
    for(int i=0;i<n;i++){
        if(d[i]==0){
            dfs(i, vertex, d, f);
        }
    }
    for(int i=0;i<n;i++){
        cout << i+1 << " " <<  d[i] << " " << f[i] << endl;
    }
    return 0;
}

void dfs(int v, vector<vector<int>>& vertex, int d[], int f[]){
    d[v] = cnt++;
    for(int i : vertex[v]){
        if(d[i]==0){
            dfs(i, vertex, d, f);
        }
    }
    f[v] = cnt++;
}