Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}
	}

	d := make([]int, n+1)
	f := make([]int, n+1)
	t := 1
	for i := 1; i <= n; i++ {
		t = dfs(&g, &d, &f, i, t)
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, d[i], f[i])
	}
}

func dfs(g *[][]int, d *[]int, f *[]int, id int, t int) int {
	if (*d)[id] > 0 {
		return t
	}
	(*d)[id] = t
	t += 1
	for i := 0; i < len((*g)[id]); i++ {
		t = dfs(g, d, f, (*g)[id][i], t)
	}
	(*f)[id] = t
	return t+1
}

C++: #include <iostream>
#include <map>
#include <vector>

using namespace std;
struct node {
    node() {};
    node(int i, int n, int* xs) : id {i}, ns {vector<int>(xs, xs+n)} {
        delete xs;
    };
    int id;
    vector<int> ns;
    int in_time;
    int out_time;
};

int dfs(map<int, node*> graph, int time, int id){
    node* n = graph[id];
    if(n->in_time > 0){
        return time;
    }
    n->in_time = ++time;
    vector<int> ns = n->ns;
    for(auto it = ns.begin(); it != ns.end(); ++it){
        time = dfs(graph, time, *it);
    }
    n->out_time = ++time;
    return time;
}

int main(){
    int n;
    cin >> n;
    map<int, node*> graph {};
    int st = 1000000000;
    for(int i = 0; i < n; ++i){
        int id;
        cin >> id;
        st = min(st, id);
        int k;
        cin >> k;
        int* ns = new int[k];
        for(int j = 0; j < k; ++j){
            cin >> ns[j];
        }
        graph[id] = new node(id, k, ns);
    }
    for(auto it = graph.begin(); it != graph.end(); ++it){
        pair<int, node*> p = *it;
        if(p.second->in_time){
            continue;
        }
        dfs(graph, 0, p.first);
    }
    for(auto it = graph.begin(); it != graph.end(); ++it){
        pair<int, node*> p = *it;
        cout << p.first << ' ' << p.second->in_time << ' ' << p.second->out_time << endl;
    }
}

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

int n, t = 0;
int A[101][101];
int d[101], f[101];

void dfs(int r) {
	d[r] = ++t;
	for (int i = 1; i <= n; i++) {
		if (A[r][i] == 1 && d[i] == 0) dfs(i);
	}
	f[r] = ++t;
	return;
}

int main() {
	int u, v, l;
	cin >> n;

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

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			A[i][j] = 0;
		}
	}

	for (int i = 1; i <= n; i++) {
		cin >> u >> l;
		for (int j = 0; j < l; j++) {
			cin >> v;
			A[u][v] = 1;
		}
	}

	dfs(1);

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

	return 0;
}

C++: #include<iostream>
#include<cstdio>
#define Lens 105
using namespace std;
int N;
int A[Lens][Lens];
int S[Lens], E[Lens];
int sum = 0;
char c[Lens];

void dns(int i)
{
	sum++;
	S[i] = sum;
	c[i] = 'g';
	for (int j = 1; j <= N; j++)
	{
		if (A[i][j] == 1 && c[j] == 'w')
			dns(j);
	}
	sum++;
	E[i] = sum;
	c[i] = 'b';
}

int main()
{
	cin >> N;
	for (int i = 1; i <= N; i++)
	{
		int k, n;
		cin >> k >> n;
		c[i] = 'w';
		for (int i = 0; i < n; i++)
		{
			int j;
			cin >> j;
			A[k][j] = 1;
		}
	}
	/*
	for (int i = 1; i <= N; i++)
	{
		for (int j = 1; j <= N; j++)
		{
			if (j > 1)
				cout << ' ';
			cout << A[i][j];
		}
		cout << endl;
	}
	*/
	dns(1);
	for (int i = 1; i <= N; i++)
	{
		cout << i << ' ' << S[i] << ' ' << E[i] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <stack>
using namespace std;
static const int MAX=101;
bool Visited[MAX]; //??\?????????????¢??????????
vector<int> Adjacency[MAX];
int dTime[MAX]; int fTime[MAX]; //?¢??????°??¶??´????¢?????????¶??´
void dfs(int j,int clock)
{

    stack<int> S;
    S.push(j);dTime[j]=++clock;
    Visited[j]=true;
    while(!S.empty())
    {
        int p=S.top(); //???????????¶??????
        if(Adjacency[p].size()==0)
        {
            S.pop();
            fTime[p]=++clock;
            continue;
        }
        int i=0;
        if(Adjacency[p].size())
          while(Visited[Adjacency[p][i]]==true)
          {
            i++;
            if(i==Adjacency[p].size()) //???????°??????????????±?????????????
            {
                S.pop();
                fTime[p]=++clock;
                break;
            }
          }
        if(i==Adjacency[p].size()) continue;
        //if founded
        S.push(Adjacency[p][i]); dTime[Adjacency[p][i]]=++clock;
        Visited[Adjacency[p][i]]=true;
    }
}
int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++) Visited[i]=false;

    for(int i=1;i<=n;i++)
    {
        int p;cin>>p;
        int num;
        cin>>num;

        for(int j=0;j<num;j++)
        {
            int t;
            cin>>t;
            Adjacency[p].push_back(t);
        }
    }
    int clock=0;
    for(int i=1;i<=n;i++)  //???????????????????????°DFS?£?????????????
    {
        if(Visited[i]==false) dfs(i,clock);
    }
    for(int i=1;i<=n;i++)
        cout<<i<<' '<<dTime[i]<<' '<<fTime[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, tt;
int M[N][N], color[N], d[N], f[N], nt[N]; 

int next(int u){
	for(int v = nt[u]; v < n; v++) {
		nt[u] = v + 1;
		if(M[u][v] = 1) 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 {
		   color[v] = BLACK;
		   S.pop();
		   f[v] = ++tt;
		}
	} 
}


void dfs() {
	for(int i = 0; i < n; i++) {
	     color[i] = WHITE;
	}	
	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 n, k , u, v;
	cin >> n;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < n; j++) {
			M[i][j] = 0;
		}
	}
	cin >> k >> u;
	u--;
	for(int i = 0; i < k; i++) {
	    cin >> v;
	    v--;
		M[u][v] = 1; 
	}
	dfs();
	return 0;
}