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 <bits/stdc++.h>
using namespace std;
using ll = long long;
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define SORT(c) sort((c).begin(),(c).end())
#define MEMSET(v, h) memset((v), h, sizeof(v))
#define sqr(x) ((x) * (x))
#define bit(n) (1LL<<(n))
#define pcnt(x) __builtin_popcountll(x)
#define PB push_back
#define MP make_pair
#define endl "\n"
using Edge = pair<int,int>;
using Graph = vector<vector<Edge>>;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
// ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

int d[110],f[110];
int t;
bool visit[110];
vector<vector<int>> vec(110);

void dfs(int a) {
  if(!visit[a]){
    visit[a] = true;
    d[a] = ++t;
    for(auto x: vec[a]) dfs(x);
    f[a] = ++t;
  }
}

int main() {
  int n; cin >> n;
  FOR(i,0,n-1){
    int u,k,v; cin >> u >> k;
    --u;
    FOR(j,1,k){
      cin >> v;
      --v;
      vec[u].PB(v);
    }
  }
  FOR(i,0,n-1) dfs(i);
  FOR(i,0,n-1) cout << i+1 << " " << d[i] << " " << f[i] << "\n";




}

C++: #include <iostream>
#include "memory.h"
#include <stack>

using namespace std;

bool matrix[100][100];
int n;

int next(int k){
	for(int i = 0; i < n; i++){
		if(matrix[k][i] == true)
			return i + 1;
	}
	return false;
}

int main(){
	int index, temp, num, current, count = 1;
	int start_end[100][2];
	stack<int> back;

	memset(matrix, 0, sizeof(matrix));
	memset(start_end, 0, sizeof(start_end));

	cin >> n;

	for(int i = 0; i < n; i++){
		cin >> index >> num;
		while(num--){
			cin >> temp;
			matrix[index-1][temp-1] = true;
		}
	}
	back.push(0);
	current = 0;
	while(!back.empty()){
		int r;
		r = next(current);
		if(start_end[current][0] == 0){
			start_end[current][0] = count;
			count++;
		}
		if(r){
			matrix[current][r-1] = false;
			back.push(current);
			current = r - 1;
		}
		else{
			if(start_end[current][1] == 0){
				start_end[current][1] = count;
				count++;
			}
			current = back.top();
			back.pop();
		}
		
	}
	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << start_end[i][0] << " " << start_end[i][1] << endl;
	}


}

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

const int white = 0, gray = 1, black = 2, N = 101;
bool G[N][N];
int n, color[N], d[N], f[N], t;

void init(){
    for (int i = 1; i <= n; i++)
    {
        color[i] = white;
    }
    t = 0;
}
void dfs(int v){
    color[v] = gray;
    t++;
    d[v] = t;
    for (int i = 1; i <= n; i++)
    {
        if (G[v][i] && color[i] == white)
        {
            dfs(i);
        }
    }
    color[v] = black;
    t++;
    f[v] = t;
}

int main(){
    int u, k, v;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> u >> k;
        for (int j = 0; j < k; j++)
        {
            cin >> v;
            G[u][v] = 1;
        }
    }
    init();
    for (int i = 1; i <= n; i++)
    {
        if (color[i] == white)
        {
            dfs(i);
        }
    }
    for (int i = 1; i <= n; i++)
    {
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
    
}

C++: //Shunji Lin 08-144505

#include <iostream>

using namespace std;

bool adjmatrix[101][101]; //adjmatrix
int discover[101];
int processed[101];
int cur_time = 0;


void DFS(int vertex, int N) {
  cur_time++;
  discover[vertex] = cur_time; // set cost
  
  for (int i =1; i<= N; i++) {
    if(adjmatrix[vertex][i] && discover[i] == -1) {
      DFS(i, N);
    }
  }
  
  cur_time++;
  processed[vertex] = cur_time;
}


  
int main() {
  const int cur_time = 0;
  
  for (int i = 0; i < 101; i++) {
    discover[i] = -1; // upper limit
    processed[i] = -1;
  }
  int N;
  cin >> N;

  for (int i = 1; i <= N; i++) {
    int vertex, degree;
    cin >> vertex >> degree;

    for (int j = 0; j < degree; j++) {
      int outvertex;
      cin >> outvertex;
      adjmatrix[i][outvertex] = true;
    }
  }

  
  //function to print adjmatrix
  for (int i = 1; i <= N; i++) {
    for (int j= 1; j <= N; j++) {
      if (adjmatrix[i][j]) {
	cout << "1 ";
      } else {
	cout << "0 ";
      }
    }
    cout << endl;
    }

  DFS(1,N);


  for (int i = 1; i <=N; i++) {
    if (discover[i] != -1) {
      cout << i << " " << discover[i] << " "<< processed[i] << endl;
    }
  }
}