Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve

const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 最初にiを訪問した時刻。発見時刻
//f[i]: iの隣接リストを訪問し終えた時刻。完了時刻
var color, d, f [MAX]int

func dfs_visit(u int) {
	color[u] = GRAY
	time++
	d[u] = time
	//隣接を調べる
	for v := 0; v < n; v++ {
		if M[u][v] == 0 {
			continue
		}
		//隣接するvが、未訪問だった場合
		if color[v] == WHITE {
			dfs_visit(v)
		}
	}
	//訪問完了処理
	color[u] = BLACK
	time++
	f[u] = time
	//訪問完了
}

func dfs() {
	//初期化
	for u := 0; u < n; u++ {
		color[u] = WHITE
	}
	time = 0

	//未訪問のuを始点として、深さ優先探索
	for u := 0; u < n; u++ {

		if color[u] == WHITE {
			dfs_visit(u)
		}
	}

	for u := 0; u < n; u++ {
		fmt.Println(u+1, d[u], f[u])
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	dfs()

}

C++: #include<iostream>
#include<stack>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

int n,M[N][N];
int color[N],d[N],f[N],tt;
int nt[N];

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

void dfs_visit(int r)
{
    for(int i=0;i<n;i++)
    {
        nt[i]=0;
    }

    stack<int> s;
    s.push(r);
    color[r]=GRAY;
    d[r]=++tt;

    while(!s.empty())
    {
        int u=s.top();
        //cout << "s.top=" << u << endl;
        int v=next(u);
        //cout << "u.next=" << v << endl;
        if(v!=-1)
        {
            if(color[v]==WHITE)
            {
                color[v]=GRAY;
                d[v]=++tt;
                s.push(v);
            }
        }
        else
        {
            s.pop();
            color[u]=BLACK;
            f[u]=++tt;
        }
    }
}

void dfs()
{
    for(int i=0;i<n;i++)
    {
        color[i]=WHITE;
        nt[i]=0;
    }


    tt=0;

    for(int u=0;u<n;u++)
    {
        if(color[u]==WHITE)
        {
            //cout << "visit " << u << endl;
            dfs_visit(u);
        }
    }

    for(int i=0;i<n;i++)
    {
        cout << i+1 << " " << d[i] << " " << f[i] << endl;
    }
}

int main()
{
    int u,k,v,node;
    cin >> n;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            M[i][j]=0;
        }
    }

    for(int i=0;i<n;i++)
    {
        cin >> u;//row
        if(i==u-1)
        {
            cin >> node;//number of node
            for(int j=0;j<node;j++)
            {
                cin >> v;
                M[i][v-1]=1;
            }
        }
    }

    /*
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            cout << M[i][j] << " " ;
        }
        cout << endl;
    }*/

    dfs();
    return 0;
}

C++: #ifdef LOCAL_BUILD
#include "pch.h"
#define DLOG(msg) cout << "#" << __LINE__ << ":" << msg << endl;
#define DLOG_V(var) \
  cout << "#" << __LINE__ << ":" << #var << " : " << var << endl;
#else
#include <bits/stdc++.h>
#define DLOG(msg)
#define DLOG_V(var)
#endif
using namespace std;

constexpr auto no_value = numeric_limits<uint64_t>::max();

struct GraphParser {
  GraphParser(vector<vector<int>>& edges_)
      : edges(edges_), start(edges.size(), 0), end(edges.size(), 0) {
    //
  }

  void run() {
    t = 0;
    for (size_t i = 0; i < edges.size(); ++i) {
      if (!start[i]) {
        recur(i);
      }
    }
  }

  vector<vector<int>>& edges;
  vector<int> start;
  vector<int> end;
  int t;

 private:
  void recur(int cur) {
    if (start[cur]) {
      return;
    }
    start[cur] = ++t;
    for (auto&& e : edges[cur]) {
      recur(e);
    }
    end[cur] = ++t;
  }
};

int main() {
  int n;
  cin >> n;
  vector<vector<int>> edges(n, vector<int>());
  for (int i = 0; i < n; ++i) {
    int u;
    int k;
    cin >> u >> k;
    edges[u - 1].reserve(k);
    for (int j = 0; j < k; ++j) {
      int v;
      cin >> v;
      edges[u - 1].push_back(v - 1);
    }
  }

  GraphParser p(edges);
  p.run();
  for (int i = 0; i < n; ++i) {
    cout << (i + 1) << " " << p.start[i] << " " << p.end[i] << endl;
  }
}

C++: // 2015/01/05 Tazoe

#include <iostream>
#include <stack>
using namespace std;

int main()
{
	int n;
	cin >> n;

	int G[100][100] = {0};

	for(int i=0; i<n; i++){
		int u, k;
		cin >> u >> k;

		for(int j=0; j<k; j++){
			int v;
			cin >> v;

			G[u-1][v-1] = 1;
		}
	}

//	for(int i=0; i<n; i++){
//		for(int j=0; j<n; j++){
//			cout << G[i][j] << ' ';
//		}
//		cout << endl;
//	}

	int d[100] = {0};
	int f[100] = {0};

	stack<int> S;
	int T = 0;

	S.push(0);
	d[0] = ++T;

	while(!S.empty()){
		int u = S.top();

		int v = -1;
		for(int j=0; j<n; j++){
			if(G[u][j]==1 && d[j]==0){
				v = j;
				break;
			}
		}

		if(v!=-1){
			S.push(v);
			d[v] = ++T;
		}
		else{
			S.pop();
			f[u] = ++T;
		}
	}

	for(int i=0; i<n; i++){
		cout << i+1 << ' ' << d[i] << ' ' << f[i] << endl;
	}

	return 0;
}

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

void get_network(int N,vector<vector<int>>& array){
    int u,k,x;

    for(int i=0;i<N;i++){
        cin>>u>>k;
        for(int j=0;j<k;j++){
            cin>>x;
            array[u-1][x-1]=1;
        }
    }

}

int dfs_rec(vector<int>& flag,int n,vector<vector<int>>& A,int v,vector<int>& f,vector<int>& d,int t){
        flag[v]=1;
        d[v]=t;
        for(int i=0;i<n;i++){
                if(A[v][i]==1 && flag[i]!=1){
                        t=dfs_rec(flag,n,A,i,f,d,t+1);

                }
        }
        f[v]=t+1;
        t++;
        return t;
}


int main(){
        cin.tie(0);
        ios::sync_with_stdio(false);

        int n;
        cin>>n;
        vector<vector<int>> array(n,vector<int>(n,0));
        get_network(n,array);

        //
        vector<int> flag(n,-1);
        vector<int> d(n,0);
        vector<int> f(n,0);
        //
        int t=0;
        t=dfs_rec(flag,n,array,0,f,d,t);
        for(int i=0;i<n;i++){
                if(flag[i]==-1){
                        t=dfs_rec(flag,n,array,i,f,d,t+1);
                }
        }
        //

        for(int i=0;i<n;i++){
                cout<<i+1<<" "<<d[i]+1<<" "<<f[i]+1<<"\n";
        }

        return 0;
}