Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

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

const int Max = 100;
const int white = 0;
const int gray = 1;
const int black = 2;

int n, M[Max][Max];
int color[Max], d[Max], f[Max], tt;
int nt[Max];

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=00; 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;

int main(){
	int n;
	cin >> n;

	int G[100][100]={0};

	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-1][v-1] = 1;
		}
	}

	int d[100] = {0};
	int f[100] = {0};

	stack<int> S;
	int T=0;

	for(int i=0; i<n; i++){
		if(d[i]!=0)
			continue;
		S.push(i);
		d[i] = ++T;

		while(!S.empty()){
			int u = S.top();
			int v = -1;
			for(int j=0; j<n; j++){
				if(G[u][j]==1 && d[j]==0){
					v = j;
					break;
				}
			}

			if(v!=-1){
				S.push(v);
				d[v] = ++T;
			}else{
				S.pop();
				f[u] = ++T;
			}
		}
	}
	
	for(int i=0; i<n; i++){
		cout << i+1 << ' ' << d[i] << ' ' << f[i] << endl;
	}
	return 0;
}

C++: #include<stdio.h>
#define N 100
#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] == 0)
     continue;
  if(color[v] == 0)
    {
      dfs_visit(v);
    }
}
  color[u] = BLACK;
  f[u] == ++tt;
}
void dfs()
{
  int u;
  for(u = 0;u<n;u++)
     color[u] = 0;
  tt = 0;
  for(u = 0;u<n;u++)
  {
    if(color[u] == 0) dfs_visit(u);
  }
  for(u = 0;u<n;u++)
  {
    printf("%d %d %d\n",u+1,d[u],f[u]);
  }
}
int main ()
{
  int u,v,k,i,j;
  scanf("%d",&n);
  for( i = 0;i<n;i++)
  {  for( j = 0;j<n;j++)
        M[i][j] = 0; }
  for( i =0;i<n;i++)
   {
     scanf("%d %d",&u,&k);
     u--;
     for( j = 0;j<k;j++)
       {
         scanf("%d",&v);
         v--;
         M[u][v] = 1;
       }
   }
   dfs();
  return  0 ;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<utility>
#include<vector>
#include<map>
#include<set>
#include<tuple>
#include<stack>
#include<queue>
#include<functional>
#include<iterator>
#include<cmath>

using namespace std;

typedef pair<int,int> P;

vector<int> g[100];
int ans[100][2]; //[i][0] 到着　　[i][1] 終了
bool used[100];

int dfs(int v,int t){
	used[v] = true;
	ans[v][0] = t++;
	for(int i=0;i<g[v].size();i++){
		if(!used[g[v][i]]) t = dfs(g[v][i],t);
	}
	ans[v][1] = t;
	return t + 1;
}

int main(){
	//ios::sync_with_stdio(false);
	//cin.tie(0);

	int n;
	cin >> n;
	
	for(int i=0;i<n;i++){
		int u, nume;
		cin >> u >> nume;

		int v;
		for(int j=0;j<nume;j++){ //jは回数数えるだけ
			cin >> v;
			g[u-1].push_back(v-1);
		}
	}

	int t=1;
	for(int i=0;i<n;i++){
		if(!used[i]){
			t = dfs(i,t);
		}
	}

	for(int i=0;i<n;i++){
		cout << i+1 << " " << ans[i][0] << " " << ans[i][1] << "\n";
	}

	return 0;
}

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

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;

int n;
int u, k, v;
int hour = 1;
int d[101] = {}, f[101] = {};
int gra[101][101] = {};
int color[101] = {};


void dfs(int u) {
	color[u] = 1;
	d[u] = hour;
	hour++;
	FOR(i, 1, n) {
		if (gra[u][i] == 1 && color[i] == 0) {
			dfs(i);
		}
	}
	color[u] = 2;
	f[u] = hour;
	hour++;
}


int main(void) {
	cin >> n;
	
	FOR(i, 1, n) {
		cin >> u >> k;
		FOR(t, 1, k) {
			cin >> v;
			gra[u][v] = 1;
		}
	}
	d[1] = hour;

	dfs(1);

	FOR(i, 1, n) {
		cout << i << " " << d[i] << " " << f[i] << endl;
	}

	return 0;
}

C++: #include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
#include<stack>

int main(){
    int n;
    scanf("%d",&n);
    int a[n+1][n+1];
    int i,j;
    for(i=1;i<=n;i++)for(j=1;j<=n;j++)a[i][j]=0;
    for(i=1;i<=n;i++){
        int q,k;
        scanf("%d %d",&q,&k);
        for(j=1;j<=k;j++) {
            int p;
            scanf("%d",&p);
            a[q][p]=1;
        }
    }
    int time=0;
    std::stack<int>S;
    int ans[n+1][3];
    
    
    
    S.push(1);
    time++;
    ans[1][1]=time;
    
    int color[n+1];
    color[1]=1;
    for(i=2;i<=n;i++)color[i]=0;//0??????????¨????
    int lastcheck=0;
    
    while(lastcheck==0){
    while(S.size()>=1){
        int flag=0;//flag=0??????pop
        for(i=1;i<=n;i++){
            if(i!=S.top()&& a[S.top()][i]==1 &&color[i]==0){
                S.push(i);
                color[i]=1;
                time++;
                ans[i][1]=time;
                flag=1;
                break;
            }
        }
        if(flag==0){
            time++;
            ans[S.top()][2]=time;
            S.pop();
        }
    }
        lastcheck=1;
        for(i=1;i<=n;i++)if(color[i]==0){
            lastcheck=0;
            break;
        }
        S.push(i);
        time++;
        ans[i][1]=time;
        
    }
    for(i=1;i<=n;i++){
        printf("%d %d %d\n",i,ans[i][1],ans[i][2]);
    }
    return 0;
}