Go: package main

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

const MAX = 101

var f [MAX]int
var d [MAX]int
var list [][]int
var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

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

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(u, cnt int) int {
	if d[u] != 0 {
		return cnt
	}

	cnt++
	d[u] = cnt
	for _, next := range list[u] {
		cnt = dfs(next, cnt)
	}
	cnt++
	f[u] = cnt
	return cnt
}

func main() {
	n := scanInt()
	list = make([][]int, n+1)
	for i := 1; i <= n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			n := scanInt()
			list[u] = append(list[u], n)
		}
	}

	cnt := 0
	for i := 1; i <= n; i++ {
		cnt = dfs(i, cnt)
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, d[i])
		fmt.Fprint(w, " ")
		fmt.Fprint(w, f[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

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

int n;
vector<vector<int> > A;
vector<vector<int> > T;
int t = 0;

void dfs(int cur){ // cur????¨????
    // cur ????¨??????????????¨????
    t += 1;
    T[cur][0] = t;
    // ???????¢??????¨??¨???
    cerr << "visiting " << cur << " " << t << endl;

    for(int dst = 0; dst < n; ++dst){ // ??¨???????????? dst ????????????
        if(A[cur][dst] == 1 && T[dst][0] == -1){ // cur??????dst??????????????????,dst???????¨??????????
            dfs(dst);
        }
    }
    // cur ????¨????????????????????¨????
    t += 1;
    T[cur][1] = t;
    // ??¢??°?????????????????????????????? (?????¢??°)
    return; // ?????\???
}

int main(){
    cin >> n;
    vector<vector<int> > A(n, vector<int>(n, 0));
    vector<vector<int> > T(n, vector<int>(2, -1));
    for(int i=0; i<n; ++i){
        int k;
        cin >> k;
        // 1~n???index?????¨????????????????????????????????????1????????????0~n-1????????????
        k -= 1;
        int u;
        cin >> u;
        for(int j=0; j<u; ++j){
            int v;
            cin >> v;
            v -= 1;
            A[k][v] = 1;
        }
    }
    for(int i=0; i<n; ++i){
        if(T[i][0] == -1){
          dfs(i);
        }
    }
    for(int i=0; i<n; ++i){
        cout << i+1 << T[i][0] << T[i][1] << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   FOR(i,0,n)
#define pb emplace_back
typedef long long ll;
typedef pair<int,int> pint;

vector<int> g[101];
bool used[101];
pint ans[101];
int cnt;
void dfs(int v){
    used[v]=true;
    ans[v].first=cnt++;
    rep(i,g[v].size()){
        if(!used[g[v][i]]){
            dfs(g[v][i]);
        }
    }
    ans[v].second=cnt++;
}
int main(){
    int n,u,k,v;
    cin>>n;
    rep(i,n){
        cin>>u>>k;
        --u;
        rep(j,k){
            cin>>v;
            --v;
            g[u].pb(v);
        }
    }
    cnt=1;
    rep(i,n){
        if(!used[i]) dfs(i);
    }
    rep(i,n) cout<<i+1<<" "<<ans[i].first<<" "<<ans[i].second<<endl;
    return 0;
}

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

int a[101][101];
int n=0;
int found[101];
int ended[101];
int aaa(int i, int time);

int main(){
  for(int i=0; i<101; i++)
    for(int j=0; j<101; j++)
      a[i][j]=0;
  int u, k, v;
  cin>>n;
  for(int i=0; i<n; i++){
    cin>>u>>k;
    for(int j=0; j<k; j++){
      cin>>v;
      a[u][v]=1;
    }
  }

  int time=0;
  for(int i=0; i<101; i++){
    found[i]=0;
    ended[i]=0;
  }

  for(int i=1; i<n+1; i++){
    if(found[i]>0)
      continue;
    time++;
    found[i]=time;
    time=aaa(i, time);
    ended[i]=time;
  } 

  for(int i=1; i<n+1; i++)
    cout<<i<<' '<<found[i]<<' '<<ended[i]<<endl;
}

int aaa(int i, int time){
  for(int k=1; k<n+1; k++){
    if(a[i][k]==1&&found[k]==0){
      time++;
      found[k]=time;
      time=aaa(k, time);
      ended[k]=time;
    } 
  }
  time++;
  return time;
}

C++: #include "bits/stdc++.h"
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];

//u?????£??\??????v?????????????????????
int next(int u){
	for (int v = 0; 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;
	//????¨???????u????§??????¨????????±???????????¢?´¢
	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;
	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>>k;
		u--;
		for (int j = 0; j < k; ++j) {
			cin>>v;
			v--;
			M[u][v]=1;
		}
	}
	dfs();
	return 0;
}

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() {

  cin >> n;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      M[i][j] = 0;
    }
  }

  int u, k, v;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    u--; // to 0 origin
    for (int j = 0; j < n; j++) {
      cin >> v;
      v--; // to 0 origin
      M[u][v] = 1;
    }
  }

  dfs();

  return 0;
}