Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

/***************************************************************
stackによる深さ優先探索を実装する。
***************************************************************/

const (
	N     = 100
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var (
	n            int
	Adj          [N][N]int
	statusColor  [N]int
	discoverTime [N]int
	finishTime   [N]int
	clock        int
	nt           [N]int
)

/***************************************************************
Stackの定義:
- field
	container: ノードの格納されたスライス
	sp: スタックポインタ
- method
	size(): スタックに積まれているノードの個数を返す
	top(): スタックの一番上に積まれているノードを返す
	isEmpty(): スタックが空かどうかを返す
	pop(): スタックの要素をポップし削除する
	push(): スタックに要素を積む
***************************************************************/

type Stack struct {
	container []int
	sp        int
}

func (s *Stack) size() int {
	return len(s.container)
}

func (s *Stack) top() int {
	return s.container[s.sp]
}

func (s *Stack) isEmpty() bool {
	return s.sp == 0
}

func (s *Stack) pop() int {
	_pop := func() {
		s.container = s.container[:len(s.container)-1]
	}
	defer _pop()
	if s.isEmpty() {
		panic("There is no elements in stack!")
	}
	s.sp--
	return s.container[s.sp]
}

func (s *Stack) push(n int) {
	s.sp++
	s.container[s.sp] = n
}

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

func _DFS(target int) {
	for i := 0; i < n; i++ {
		nt[i] = 0
	}
	stack := new(Stack)
	stack.container = make([]int, N+1)
	stack.push(target)
	statusColor[target] = GRAY
	clock++
	discoverTime[target] = clock
	for !stack.isEmpty() {
		u := stack.top()
		v := next(u)
		if v != -1 {
			if statusColor[v] == WHITE {
				statusColor[v] = GRAY
				clock++
				discoverTime[v] = clock
				stack.push(v)
			}
		} else {
			stack.pop()
			statusColor[u] = BLACK
			clock++
			finishTime[u] = clock
		}
	}
}

func DFS() {
	for i := 0; i < n; i++ {
		statusColor[i] = WHITE
		nt[i] = 0
	}
	clock = 0
	for i := 0; i < n; i++ {
		if statusColor[i] == WHITE {
			_DFS(i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, discoverTime[i], finishTime[i])
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			Adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ := strconv.Atoi(scanner.Text())
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		u--
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ := strconv.Atoi(scanner.Text())
			v--
			Adj[u][v] = 1
		}
	}

	DFS()
}

C++: 
 // C
 #ifndef _GLIBCXX_NO_ASSERT
 #include <cassert>
 #endif
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
 #include <ciso646>
 #include <climits>
 #include <clocale>
 #include <cmath>
 #include <csetjmp>
 #include <csignal>
 #include <cstdarg>
 #include <cstddef>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <ctime> 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 #include <ccomplex>
 #include <cfenv>
 #include <cinttypes>
 #include <cstdbool>
 #include <cstdint>
 #include <ctgmath>
 #include <cwchar>
 #include <cwctype>
 #endif
 
 // C++
 #include <algorithm>
 #include <bitset>
 #include <complex>
 #include <deque>
 #include <exception>
 #include <fstream>
 #include <functional>
 #include <iomanip>
 #include <ios>
 #include <iosfwd>
 #include <iostream>
 #include <istream>
 #include <iterator>
 #include <limits>
 #include <list>
 #include <locale>
 #include <map>
 #include <memory>
 #include <new>
 #include <numeric>
 #include <ostream>
 #include <queue>
 #include <set>
 #include <sstream>
 #include <stack>
 #include <stdexcept>
 #include <streambuf>
 #include <string>
 #include <typeinfo>
 #include <utility>
 #include <valarray>
 #include <vector> 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 #include <array>
 #include <atomic>
 #include <chrono>
 #include <condition_variable>
 #include <forward_list>
 #include <future>
 #include <initializer_list>
 #include <mutex>
 #include <random>
 #include <ratio>
 #include <regex>
 #include <system_error>
 #include <thread>
 #include <tuple>
 #include <typeindex>
 #include <type_traits>
 #include <unordered_map>
 #include <unordered_set>
 #endif 
using namespace std;
using Graph = vector< vector<int> >;
bool seen[110];
int d[110];
int f[110];

void dfs(Graph &G,int v,int &time){
    seen[v] = true;
    d[v] = time++;
    for(auto nv : G[v]){
        if(seen[nv]) continue;
        dfs(G,nv,time);
    }
    f[v] = time++;
}

int main(){
    int n; cin >> n;
    Graph G(n);
    for(int i=0;i<n;++i){
        int u,k; cin >> u >> k;
        --u;
        if(k==0) continue;
        for(int j=0;j<k;++j){
            int v;
            cin >> v;
            --v;
            G[u].push_back(v);
        }
    }
    int time = 1;
    for(int v=0;v<n;++v){
        if(seen[v]) continue;
        dfs(G,v,time);
    }
    
   
    for(int v=0;v<n;++v){
        cout << v+1 << ' ' << d[v] << ' ' << f[v] << endl;
    }
    return 0;
}

C++: /*
 * ALDS1_11_B.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<iostream>
#include<vector>

using namespace std;

int d[101];
int f[101];
int nowTime;

void dfsRec(vector<int>* a, int n, int v) {
	if(d[v] > 0) return;
	nowTime++;
	d[v] = nowTime;
	for(int &x:a[v]) {
		dfsRec(a, n, x);
	}
	nowTime++;
	f[v] = nowTime;
}

int main() {
	int n;
	vector<int> adj[101];

	cin >> n;
	for(int i=0; i<n; i++) {
		int v;
		int k;
		cin >> v >> k;
		for(int j=0; j<k; j++) {
			int u;
			cin >> u;
			adj[v].push_back(u);
		}
	}

	for(int i=1; i<=n; i++) {
		if(d[i] ==0) dfsRec(adj, n, i);
	}

	for(int i=1; i<=n; i++) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}
}

C++: /**
 * Depth first search.
 * start from node 1
 * 1) increment time 
 * 2) find non visited adjacent node
 * 3) if found move to that node.  d[v'] = time
 * 4) if not found. f[v] = time
 * 5) else end.
 * 5) go to 2.
 */

#include <iostream>
using namespace std;
const int N = 101;
int adj[N][N] = {0};
int d[N]={0};
int f[N]={0};
int t = 0;

void dfs(int n) {
	if (d[n]) return;
	d[n]=++t;
	int k = adj[n][0];
	for (int j=1;j<=k;j++) {
		dfs(adj[n][j]);
	}
	f[n]=++t;
}

int main()
{
	int n;
	cin >> n;
	for (int i=1;i<=n;i++){
		int j, k;
		cin >> j >> k;
		adj[j][0]=k;
		for (int m=1;m<=k;m++) {
			int a;
			cin >> a;
			adj[j][m]=a;
		}
	}

	for (int i=1;i<=n;i++){
		dfs(i);
	}

	for (int i=1;i<=n;i++){
		cout << i << ' ' << d[i] << ' ' << f[i] << endl;
	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

void Main()
{
  set<int> visited;
  stack<int> s;
  int n; cin >> n;
  vector<int> stt(n+1), end(n+1), K(n+1);
  vector<vector<int> > A(n+1, vector<int>(n+1));
  for(int i = 0; i < n; i++) {
    int u; cin >> u;
    cin >> K[u];
    for (int j = 0; j < K[u]; j++) cin >> A[u][j];
  }
  s.push(1);
  int time = 1;
  bool popped = false;
  while (true) {
    //if (!popped) time++;
    //popped = false;
    if (s.size() == 0) {
      for (int i = 1; i <= n; i++) {
        if (visited.find(i) == visited.end()) {
          s.push(i);
          break;
        }
      }
      if (s.size() == 0) break;
      else {time++; continue;}
    }
    int cur = s.top();
    //cout << time << ' ' <<  cur << endl;
    if (visited.find(cur) == visited.end()) {
      visited.insert(cur);
      stt[cur] = time;
    }
    bool done = true;
    for(int i = 0; i < K[cur]; i++) {
      int nxt = A[cur][i];
      if (visited.find(nxt) == visited.end()) {
      	s.push(nxt);
        time++;
        done = false;
        break;
      }
    }
    if (done) {
      time++;
      end[cur] = time;
      s.pop();
      popped = true;
    }
  }
  for(int i = 0; i < n+1; i++) {
    if (i==0) continue;
    cout << i << ' ' << 
      stt[i] << ' ' << end[i] << endl;
  }
}

int main()
{
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  Main();
  return 0;
}