Go: package main

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

var N int
var A [][]int
var t int
var color, d, f []int

const (
	WHITE = iota
	GRAY
	BLACK
)

func dfsVisit(u int) {
	color[u] = GRAY
	t ++
	d[u] = t
	for v:=0; v<N; v++ {
		if A[u][v] == 0 {
			continue
		}
		if color[v] == WHITE {
			dfsVisit(v)
		}
	}
	color[u] = BLACK
	t++
	f[u] = t
}

func dfs() {
	for u:=0; u<N; u++ {
		if color[u] == WHITE {
			dfsVisit(u)
		}
	}
	for u:=0; u<N; u++{
		fmt.Printf("%d %d %d\n", u+1, d[u], f[u])
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	color = make([]int, N)
	d = make([]int, N)
	f = make([]int, N)
	A = make([][]int, N)
	for i:=0; i<N; i++{
		A[i] = make([]int, N)
	}
	for i:=0; i<N; i++{
		index := nextInt(scanner) - 1
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			v := nextInt(scanner) - 1
			A[index][v] = 1
		}
	}
	dfs()
}

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;
//?????\??????
int M[N][N];
//??°?????¶???????¢????
int color[N];
//??\??¶????????°??¶???
int d[N];
//??\??¶???????????¶???
int f[N];
//??¶???
int tt;
//???????????????????????????????????????
//?????¨?????????????????¨????????\??????????????????
int nt[N];

//????????????????????????u?????????v
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&&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++)
        nt[i]=0,color[i]=WHITE;
    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();
}

C++: #include<iostream>

int main(){

  int n,a;
  std::cin>>n;

  int Adj[100][100],adj[100][100]={0},find[100][2],back[100],depth[100]={0},endflag[100]={0},flag;
  int u[n],k[n],kcou=0,timenow=0,v,pred,prev,firstv;
  for(int i=0;i<n;i++){
    std::cin>>u[i];
    std::cin>>k[i];
    for(int j=0;j<k[i];j++){
      std::cin>>Adj[i][j];
    }
  }
	
	/*
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
    	std::cout<<Adj[i][j]<<" ";
    }
  	std::cout<<"\n";
  }*/
	
	v=0;
	firstv=0;
	while(timenow<n*2){
		flag=0;
		if(find[firstv][0]!=NULL&&find[firstv][1]!=NULL){
			for(int i=0;i<n;i++){
				if(find[i][0]==NULL){
					//std::cout<<i<<"\n";
					firstv=i;
					v=i;
					break;
				}
			}
		}
		//std::cout<<v;
		///std::cout<<find[v][0]<<" "<<find[v][1];
		if(find[v][0]==NULL){
			timenow++;
			find[v][0]=timenow;
			flag=1;
			//std::cout<<flag<<" 1";
		}else if(find[v][1]==NULL){
			if(endflag[v]==1){
				timenow++;
				find[v][1]=timenow;
				flag=2;
			}
			//std::cout<<flag<<" 2";
		}else{
			v=back[v];
			flag=3;
			//std::cout<<flag<<" 0";
		}

		if(flag==0){
			pred=depth[v];
			depth[v]++;
			prev=v;
			v=Adj[v][pred]-1;
			back[v]=prev;
			//std::cout<<flag<<"\n";
		}else if(flag==1){
			if(endflag[v]==0){
				if(Adj[v][depth[v]]-1!=v){
					pred=depth[v];
					depth[v]++;
					prev=v;
					v=Adj[v][pred]-1;
					back[v]=prev;
					//std::cout<<v<<"\n";
				}else{
					pred=depth[v];
					depth[v]++;
				}
			}
		}else if(flag==2){
			v=back[v];
			//std::cout<<flag<<"\n";
		}
		if(depth[v]>k[v]-1){
			endflag[v]=1;
		}
		
	}
	
	
	
	
  for(int i=0;i<n;i++){
     std::cout<<i+1<<" "<<find[i][0]<<" ";
     std::cout<<find[i][1]<<"\n";
    //std::cout<<"\n";
  }

  return 0;
}

C++: #include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i,n) for(int i=0, i##_len=(int)(n); i<i##_len; i++)
#define reps(i,n) for(int i=1 , i##_len=(int)(n);i<=i##_len;i++)
#define rrep(i,n) for(int i=((int)(n)-1);i>=0;i--)
#define rreps(i,n) for(int i=((int)(n));i>0;i--)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define solve(a) ((a)?"Yes":"No")
typedef vector<long long> V;
typedef vector<V> VV;
typedef pair<long long , long long> P;
typedef vector<P> VP;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1;} return 0;}
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1;} return 0;}
const long long INFLL = 1LL<<62;
const int INF = 1<<30;
const double PI=acos(-1);
int func(int serching,vector<vector<int>>&path,vector<pair<int,int>>&data,int no,vector<bool>&has){
    has[serching]=true;
    chmin(data[serching].F,no);
  
  // clog<<serching<<" in : "<<no<<endl;
    no++;
    for(auto itr=path[serching].begin();itr!=path[serching].end();itr++){
        if(has[*itr]==false){
       no= func(*itr,path,data,no,has);
        }
    }
    chmax(data[serching].S, no);
  //  clog << serching <<  " out : " << no << endl;
    return no+1;
}
int main(){
    int n;
    cin >>n;
    vector<vector<int>>path(n);
    vector<bool>has(n,false);
    vector<pair<int,int>>data(n,mp(INF,0));
    queue<int>q;
    q.push(0);
    int at;
    int u,k;
    int bef;
    rep(i,n){
        cin>>u>>k;
        u--;
        rep(j,k){
            cin>>bef;
            bef--;
            path[u].push_back(bef);
         //   clog<<u<< " -> "<<bef<<endl;
        }
    }
    rep(i,u){
        sort(all(path[i]));
    }
    int no=1;
    rep(i,n){
        if(has[i]==false){
       no= func(i,path,data,no,has);
        }
    }
    rep(i,n){
        printf("%d %d %d\n",i+1,data[i].F,data[i].S);
    }
}

C++: /*
 * ALDS1_11_B.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<iostream>
#include<vector>

using namespace std;

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

void dfsRec(vector<int>* a, int n, int v) {
	if(d[v] > 0) return;
	time++;
	d[v] = time;
	for(int &x:a[v]) {
		dfsRec(a, n, x);
	}
	time++;
	f[v] = time;
}

int main() {
	int n;
	vector<int> adj[101];

	cin >> n;
	for(int i=0; i<n; i++) {
		int v;
		int k;
		cin >> v >> k;
		for(int j=0; j<k; j++) {
			int u;
			cin >> u;
			adj[v].push_back(u);
		}
	}

	dfsRec(adj, n, 1);

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