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<cstdio>
#include<cstring>
#include<vector>
#include<queue>
#include<algorithm>
#include<cmath>
#include<climits>
#include<string>
#include<set>
#include<numeric>
#include<map>
#include<iostream>
using namespace std;
#define rep(i,n) for(int i = 0;i<((int)(n));i++)
#define reg(i,a,b) for(int i = ((int)(a));i<=((int)(b));i++)
#define irep(i,n) for(int i = ((int)(n)-1);i>=0;i--)
#define ireg(i,a,b) for(int i = ((int)(b));i>=((int)(a));i--)
typedef long long ll;
typedef pair<ll, ll> mp;


int visitTime = 1;
int d[101],f[101],n[101],v[101][101],id;


void dfs(int cur) { // cur????¨????
	d[cur] = visitTime;// cur????¨??????????????¨????
	visitTime += 1;
	rep(i,n[cur]){ // ??¨????????? v[cur][i] ????????????
		if(d[v[cur][i]]==0){ // v[cur][i] ???????¨??????????
			dfs(v[cur][i]);
		}
	}
	f[cur] = visitTime;// cur ????¨????????????????????¨????
	visitTime += 1;
	// ??¢??°??????????????§???????????? (?????¢??°)
}

int main(void){
	int N;
	cin>>N;
	rep(i,N){
		cin>>id;
		cin>>n[id];
		rep(j,n[id])cin>>v[id][j];
	}
	dfs(1);
	reg(i,1,N)cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
	return 0;
}

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

const int MAX_N = 100;
vector<int> G[MAX_N];
int d[MAX_N], f[MAX_N];
bool used[MAX_N];

int stamp;

void dfs(const int v) {
    d[v] = stamp++;
    used[v] = true;
    for(int i = 0; i < (int)G[v].size(); i++) {
        int u = G[v][i];
        if(used[u] == false) dfs(u);
    }
    f[v] = stamp++;
}

int main() {
    int N; cin >> N;
    for(int i = 0; i < N; i++) {
        int u, k; cin >> u >> k; u--;
        while(k--) {
            int v; cin >> v; v--;
            G[u].push_back(v);
        }
        sort(G[u].begin(), G[u].end());
    }

    fill(used, used + N, false);
    stamp = 1;
    for(int i = 0; i < N; i++) {
        dfs(i);
    }

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

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

vector<int> G[100];
pair<int, int> T[100];
const int Inf = 10000*100000+100;
int timer = 1;

int main() {
  void dfs(int cur);
  int n;
  cin >> n;
  for (int i = 0; i < n; i++)
  {
    int u, k;
    cin >> u >> k;
    for (int l = 0; l < k; l++) {
      int v;
      cin >> v;
      G[i].push_back(v - 1);
    }
    T[i] = make_pair(Inf, Inf);
  }
  for (int i = 0; i < n; i++) {
    if (T[i].first == Inf) {
      dfs(i);
    }
  }
  for (int i = 0; i < n; i++)
  {
    cout << i + 1 << " " << T[i].first << " " << T[i].second << endl;
  }
}

void dfs(int cur) { // cur を訪問
  // cur の訪問時刻を記録
  T[cur].first = timer;
  timer += 1;
  // 動作確認用表示
  for (int dst : G[cur]) { // 全ての節点 dst について
    if (T[dst].first == Inf)
    { // cur から dst に辺があり，dst を未訪問なら
      dfs(dst);
    }
  }
  T[cur].second = timer;
  timer += 1;
}

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

int n;
bool G[110][110];
int d[110], f[110], timer;
bool seen[110];

void dfs(int now){
    d[now] = timer;

    seen[now] = true;

    for(int to=1; to<=n; ++to){
        if(G[now][to] == true && seen[to] == false){
            ++timer;
            dfs(to);
        }
    }

    ++timer;
    f[now] = timer;

}

int main(){
    cin >> n;
    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][v] = true;
        }
    }

    timer = 0;
    for(int i=1; i<=n; ++i){
        if(seen[i] == false){
            ++timer;
            dfs(i);
        }
    }

    for(int i=1; i<=n; ++i){
        printf("%d %d %d\n", i, d[i], f[i]);
    }
}

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

int t=1;
int n;
int d[101],f[101];
int v[101];
vector<int> edges[101];

void dfs(int cur)
{
    if(d[cur]==-1)
    {
        d[cur]=t;
        v[cur]=1;
        t+=1;
    }
    int dst;
    for(dst=1;dst<=n;dst++)
    {
        int flag=0;
        for(int i=0;i<edges[cur].size();i++)
        {
            if(edges[cur][i]==dst)
				{
					flag=1;
					break;
				}
        }
        if(v[dst]==-1&&flag)
		  dfs(dst);
    }
    if(f[cur]==-1)
    {
        f[cur]=t;
        t+=1;
    }
}

int main()
{
	cin >> n;
	for(int i=0;i<n;i++)
	{
		int u,k,y;
		cin >> u >> k;
		for(int j=0;j<k;j++)
        {
            cin >> y;
            edges[u].push_back(y);
        }
	}
	for(int i=1;i<=n;i++)
	{
        d[i]=-1;
        f[i]=-1;
        v[i]=-1;
    }
	for(int dst=1;dst<=n;dst++)
        dfs(dst);
	for(int i=1;i<=n;i++)
	   cout << i << ' ' << d[i] <<  ' ' <<  f[i] <<  endl;
}

C++: #include <bits/stdc++.h> 

#define int long long
#define double long double

#define REP(i, b) for(int i = 0; i < (b); i++)
#define REPS(i, b) for(int i = 1; i <= (b); i++)
#define ALL(v) (v).begin(), (v).end()

#define fi first
#define se second
#define pb push_back
#define mp make_pair

using namespace std;

using pi = pair<int, int>;
using vi = vector<int>;
using vd = vector<double>;
using vs = vector<string>;
using vb = vector<bool>;
using vpi = vector<pi>;
using vvi = vector<vi>;
using vvb = vector<vb>;

const int INF = 1e16;
const int MOD = 1e9+7;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

int n;
vi d, f;
vvi G;
int t = 0;

void dfs(int n)
{
    t++;
    d[n] = t;
    for(int i : G[n]) if(d[i] == 0) dfs(i);
    t++;
    f[n] = t;
}

signed main()
{
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    cin >> n;
    G.resize(n+1);
    d.resize(n+1, 0);
    f.resize(n+1, 0);
    REP(i, n)
    {
        int u, k; cin >> u >> k;
        REP(j, k)
        {
            int v; cin >> v;
            G[u].pb(v);
        }
    }

    REPS(i, n)
    {
        if(d[i] == 0) dfs(i);
    }

    REPS(i, n) cout << i << " " << d[i] << " " << f[i] << endl;
}