Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #include<bits/stdc++.h>
#include<limits.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)

#define MAX 200

vector<vector<int>> adj_mat(MAX, vector<int>(MAX, 0));
vector<int> d(MAX, -1); //頂点を訪問したステップを記録
vector<int> f(MAX, -1); //頂点の隣接リストを探索し終えたステップを記録

int n;
int step = 1;

void dfs(int init_node){
    stack<int> s;
    int node = init_node;
    s.push(node);
    d.at(node) = step;

    int next_node = -1;
    while(1){
        step++;

        next_node = -1;
        rep(i, n){
            if(adj_mat.at(node).at(i) == 1 && d.at(i) == -1){
                next_node = i;
                break;
            }
        }

        if(next_node == -1){        //新たなノードがない場合
            s.pop();            //次のノードが存在しないノードをスタックから削除
            if(s.size() == 0){
                f.at(node) = step;
                step++;
                break;
            }
            next_node = s.top();

            f.at(node) = step;   // 新たなノードがないので訪問ずみ
            // cout << "node not found " << node+1 << "    " << next_node+1 << endl;
        }else{                      //新たなノードがある場合
            s.push(next_node);
            d.at(next_node) = step; // 初めて見つけたノードとして記録
            // cout << "node found " << node+1 << " --> " << next_node+1 << endl;
        }
        
        node = next_node;
    }
}

int main(){
    cin >> n;

    // 隣接行列の作成
    rep(i, n){
        int u, k; cin >> u >> k;
        rep(j, k){
            int v; cin >> v;
            adj_mat.at(u-1).at(v-1) = 1;
        }
    }


    rep(i, n){
        if(d.at(i) == -1){
            dfs(i);
        }
    }

    rep(i, n){
        cout << i + 1 << " " << d.at(i) << " " << f.at(i) << endl;
    }


}

C++: #include <iostream>
#include <vector>
using namespace std;
vector<vector<int>> adjlist;
int t=0;
vector<int> d;
vector<int> f;
void input(int n){
	vector<int> f={0,0};
	adjlist.push_back(f);
  for(int i=0;i<n;i++){
    vector<int> list;
    int ln;
    cin>>ln;
    list.push_back(ln);
    cin>>ln;
    list.push_back(ln);
    for(int j=0;j<ln;j++){
      int an;
      cin>>an;
      list.push_back(an);
    }
    adjlist.push_back(list);
  }
}

void depth_search(int id){
	vector<int> list=adjlist[id];
	for(int j=0;j<list[1];j++){
		if(d[list[2+j]]<0){
			d[list[2+j]]=++t;
			depth_search(list[2+j]);
		}
	}
	f[id]=++t;
}
 
void print(int n){
  for(int i=1;i<n+1;i++){
    cout<<i<<' '<<d[i]<<' '<<f[i]<<endl;
  }
}
int main(){
  int n;
  cin>>n;
	d=vector<int> (n+1,-1);
	f=vector<int> (n+1,-1);
  input(n);
	for(int i=1;i<n+1;i++){
		if(f[i]<0){
			d[i]=++t;
			f[i]=t;
			depth_search(i);
		}
	}
  print(n);
  return 0;
}

C++: #include <iostream>
#include <iomanip> // << fixed << setprecision(xxx)
#include <algorithm> // do { } while ( next_permutation(A, A+xxx) ) ;
#include <vector>
#include <string> // to_string(nnn) // substr(m, n) // stoi(nnn)
#include <complex>
#include <tuple> // get<n>(xxx)
#include <queue>
#include <stack>
#include <map> // if (M.find(key) != M.end()) { }
#include <set> // S.insert(M);
// if (S.find(key) != S.end()) { }
// for (auto it=S.begin(); it != S.end(); it++) { }
// auto it = S.lower_bound(M);
#include <random> // random_device rd; mt19937 mt(rd());
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib> // atoi(xxx)
using namespace std;

#define DEBUG 0 // change 0 -> 1 if we need debug.
// insert #if<tab> by my emacs. #if DEBUG == 1 ... #end

typedef long long ll;

// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

// const int C = 1e6+10;
// const ll M = 1000000007;

class Edge {
public:
  int src, dst, cost;
  Edge(int s, int d, int c)
    : src(s), dst(d), cost(c) {}
  friend bool operator<(const Edge& x, const Edge& y) {
    return x.cost < y.cost;
  }
};

typedef Edge State;

class Graph {
public:
  int N;
  vector<Edge>* V;
  int* visited;
  int* from;
  int time;
  int* time_d;
  int* time_f;

  Graph(int n)
    : N(n), time(0) {
    V = new vector<Edge>[N];
    from = new int[N];
    time_d = new int[N];
    time_f = new int[N];
    visited = new int[N];
    fill(visited, visited+N, 0);
  }
  ~Graph() {
    delete[] V;
    delete[] from;
    delete[] time_d;
    delete[] time_f;
    delete[] visited;
  }

  void add_edge(int src, int dst, int cost = 1) {
    V[src].push_back(Edge(src, dst, cost));
  }

  void dfs(int start) {
    stack<State> S;
    S.push(State(-1, start, 0));
    while (!S.empty()) {
      State s = S.top();
      S.pop();
      if (visited[s.dst] == 0) {
        visited[s.dst] = 1;
        time_d[s.dst] = time++;
        from[s.dst] = s.src;
        S.push(s);
        for (auto x : V[s.dst]) {
          if (visited[x.dst] == 0) {
            S.push(State(s.dst, x.dst, s.cost + x.cost));
          }
        }
      } else if (visited[s.dst] == 1) {
        visited[s.dst] = 2;
        time_f[s.dst] = time++;
      }
    }
  }
};

int main () {
  int n;
  cin >> n;
  Graph graph(n);
  for (auto i = 0; i < graph.N; ++i) {
    int u, k;
    cin >> u >> k;
    --u;
    for (auto j = 0; j < k; ++j) {
      int v;
      cin >> v;
      --v;
      graph.add_edge(u, v);
    }
  }
  for (auto i = 0; i < graph.N; ++i) {
    sort(graph.V[i].begin(), graph.V[i].end());
    reverse(graph.V[i].begin(), graph.V[i].end());
  }
  while (true) {
    bool used = false;
    for (auto i = 0; i < graph.N; ++i) {
      if (graph.visited[i] == 0) {
        graph.dfs(i);
        used = true;
        break;
      }
    }
    if (!used) break;
  }
  for (auto i = 0; i < graph.N; ++i) {
    cout << i+1
         << " " << graph.time_d[i]+1
         << " " << graph.time_f[i]+1 << endl;
  }
}