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<iostream>
#include<cmath>
#include<algorithm>
#include<string>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<iomanip>
#include<bitset>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
typedef pair<ll,P> P1;
typedef pair<P,P> P2;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define fi first
#define sc second
#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())

const int MAX = 510000;
const int MOD = 1000000007;
using Graph = vector<vector<ll> >;

vector<bool> seen;
vector<ll> first_order;
vector<ll> last_order;

void dfs(const Graph &G, ll v, ll& ptr) {
    // 行きがけ順をインクリメントしながらメモ
    first_order[v] = ptr++;

    seen[v] = true;
    for (auto next_v : G[v]) {
        if (seen[next_v]) continue;
        dfs(G, next_v, ptr);
    }

    // 帰りがけ順をインクリメントしながらメモ
    last_order[v] = ptr++;
}

int main(){
  ll N; cin >> N;
  Graph G(N);

  rep(i,N){
    ll a; cin >> a;
    ll k; cin >> k;
    rep(j,k){
      ll to; cin >> to; to--;
      G[i].pb(to);
    }
  }

  seen.assign(N, false);
  first_order.resize(N);
  last_order.resize(N);

  ll ptr = 1;

  rep(i, N){
    if(!seen[i]) dfs(G, i, ptr);
  }

  rep(i , N){
    cout << i + 1 << " " << first_order[i] << " " << last_order[i] << endl;
  }
}

C++: #include<iostream>
#include<stack>
using namespace std;
static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int 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();
    int v = next(u);
    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 ) dfs_visit(u);
  }
  for ( int i = 0; i < n; i++ ) {
    cout << i+1 << " " << d[i] << " " << f[i] << endl;
  }
}

int main() {
  int u, k, v;

  cint >> 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 >> k;
    u--;
    for ( int j = 0; j < k; j++ ) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();

  return 0;
}

C++: #include <iostream>

using namespace std;

int V[101][101];
int n;

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

int t = 1;
void dfs(int src){
  t++;
  for(int i=1;i<=n;i++){
    if(V[src][i] != 0 && !d[i]){
      d[i] = t;
      dfs(i);
      t++;
    }
  }
  f[src] = t;
}
int main(){
  int  src, dst, num, non_visited;
  cin >> n;
  for(int i=1;i<=n;i++){
    d[i] = 0; f[i] = 0;
  }
  for(int i=1;i<=n;i++){
    cin >> src >> num;
    for(int j=0;j<num;j++){
      cin >> dst;
      V[src][dst] = 1;
    }
  }
  non_visited = 1;
  do{
    d[non_visited] = t;
    dfs(non_visited);
    non_visited = 0;
    for(int i=1;i<=n;i++){
      if(!d[i]){
        non_visited = i;
        break;
      }
    }
    t++;
  }while(non_visited);

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

C++: #include <cstdio>
#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;

void dfs_visit(int u) {
	int v;
	color[u] = GRAY;
	d[u] = ++tt;
	for (v = 0; v < n; ++v) {
		if (!M[u][v]) continue;
		if (color[v] == WHITE) {
			dfs_visit(v);
		}
	}
	color[u] = BLACK;
	f[u] = ++tt;
}

void dfs() {
	for (int u = 0; u < n; ++u) color[u] = WHITE;
	tt = 0;

	for (int u = 0; u < n; ++u) {
		if (color[u] == WHITE) dfs_visit(u);
	}
	for (int u = 0; u < n; ++u) {
		printf("%d %d %d\n", u + 1, d[u], f[u]);
	}
}

int main() {
	int u, v, k;

	scanf("%d", &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) {
		scanf("%d %d", &u, &k);
		u--;
		for (int j = 0; j < k; ++j) {
			scanf("%d", &v);
			v--;
			M[u][v] = 1;
		}
	}

	dfs();
}