Cómo Mantener un CHANGELOG

Esta es una buena referencia de como mantener un changelog para tus apps

http://keepachangelog.com/es/

How to Keep a CHANGELOG

This is a good reference on how to keep a change log for your apps

http://keepachangelog.com/en/

Paco Herrera - Mi cárcel no tiene rejas

The 20 Rings of Power - Los 20 Anillos de Poder

Three Rings for the Elven-kings under the sky,
Seven for the Dwarf-lords in their halls of stone,
Nine for Mortal Men doomed to die,
One for the Dark Lord on his dark throne,
In the Land of Mordor where the Shadows lie,
One ring to rule them all, one ring to find them,
One ring to bring them all and in the darkness bind them
In the Land of Mordor where the Shadows lie.

Tres Anillos para los Reyes Elfos bajo el cielo.
Siete para los Señores Enanos en palacios de piedra.
Nueve para los Hombres Mortales condenados a morir.
Uno para el Señor Oscuro, sobre el trono oscuro
en la Tierra de Mordor donde se extienden las Sombras.
Un Anillo para gobernarlos a todos. Un Anillo para encontrarlos,
un Anillo para atraerlos a todos y atarlos en las tinieblas
en la Tierra de Mordor donde se extienden las Sombras.

Robar una sesión RDP sin tener la contraseña

RP phonemes: pronunciation tips (BBC learning English)

How to: Work at Google — Example Coding/Engineering Interview

In the following video they show you some algorithms, here is my implementation, that also compares performance.

And here is my code code:

	import java.util.Arrays;
	import java.util.HashSet;
	import java.util.Random;
	import java.util.concurrent.TimeUnit;
	/**
	*
	* @author franci
	*/
	public class WorkAtGoogleExample
	{
	static final int MAGIC = 8;
	public static void main(String[] args)
	{
	long nanos0 = 0;
	long nanos1 = 0;
	long nanos2 = 0;
	long nanos3 = 0;
	long count0 = 0;
	long count1 = 0;
	long count2 = 0;
	long count3 = 0;
	long limit = TimeUnit.SECONDS.toNanos(20);
	boolean changed = true;
	Random rand = new Random(0x123456);
	for(int i=0;changed&&i<10000;i++)
	{
	changed = false;
	int[] items0 = rand.ints(i*i).toArray();
	for(int j=0;j<items0.length;j++)
	{
	items0[j] = items0[j] % 32;
	}
	if(nanos0<limit)
	{
	long t0 = System.nanoTime();
	int[] ret0 = findRandom(items0, i);
	long t1 = System.nanoTime();
	nanos0 += (t1-t0);
	count0++;
	changed=true;
	}
	if(nanos1<limit)
	{
	long t0 = System.nanoTime();
	int[] items1 = items0.clone();
	Arrays.sort(items1);
	int[] ret1 = findSorted(items1, i);
	long t1 = System.nanoTime();
	nanos1 += (t1-t0);
	count1++;
	changed=true;
	}
	if(nanos2<limit)
	{
	long t0 = System.nanoTime();
	int[] ret2 = findTwoLoops(items0, i);
	long t1 = System.nanoTime();
	nanos2 += (t1-t0);
	count2++;
	changed=true;
	}
	long t3 = System.nanoTime();
	if(nanos2<limit)
	{
	long t0 = System.nanoTime();
	int[] items3 = items0.clone();
	Arrays.sort(items3);
	int[] ret3 = findTwoLoops(items3, i);
	long t1 = System.nanoTime();
	nanos3 += (t1-t0);
	count3++;
	changed=true;
	}
	long t4 = System.nanoTime();
	if(i%100==0)
	{
	System.out.println(i+"=>"+i*i);
	System.out.println("findRandom= "+count0+" => "+TimeUnit.NANOSECONDS.toMillis(nanos0)+" ms");
	System.out.println("findSorted= "+count1+" => "+TimeUnit.NANOSECONDS.toMillis(nanos1)+" ms");
	System.out.println("findTwoLoops= "+count2+" => "+TimeUnit.NANOSECONDS.toMillis(nanos2)+" ms");
	System.out.println("findTwoLoops+sort="+count3+" => "+TimeUnit.NANOSECONDS.toMillis(nanos3)+" ms");
	System.out.println("------------------------------------------");
	}
	}
	System.out.println("nanos0="+count0+" =>"+TimeUnit.NANOSECONDS.toMillis(nanos0)+" ms");
	System.out.println("nanos1="+count1+" =>"+TimeUnit.NANOSECONDS.toMillis(nanos1)+" ms");
	System.out.println("nanos2="+count2+" =>"+TimeUnit.NANOSECONDS.toMillis(nanos2)+" ms");
	System.out.println("nanos3="+count3+" =>"+TimeUnit.NANOSECONDS.toMillis(nanos3)+" ms");
	}
	static int[] findSorted(int[] sample, int x)
	{
	int d=0;
	int u=sample.length-1;
	while(d<u)
	{
	int dv = sample[d];
	int uv = sample[u];
	int X = dv+uv;
	if(X==x)
	{
	return new int[]{dv,uv};
	}
	if(X<x)
	{
	d++;
	}
	else
	{
	u--;
	}
	}
	return null;
	}
	static int[] findTwoLoops(int[] sample, int x)
	{
	for(int i=0;i<sample.length-1;i++)
	{
	for(int j=i+1;j<sample.length;j++)
	{
	if(sample[i]+sample[j]==x)
	{
	return new int[]{sample[i],sample[j]};
	}
	}
	}
	return null;
	}
	static int[] findRandom(int[] sample, int x)
	{
	HashSet<Integer> set = new HashSet<>();
	for(int i=0;i<sample.length;i++)
	{
	int s2nd = sample[i];
	int f1st = x-s2nd;
	if(set.contains(f1st))
	{
	return new int[]{f1st,s2nd};
	}
	set.add(s2nd);
	}
	return null;
	}
	}

view raw WorkAtGoogleExample.java hosted with ❤ by GitHub

The results are the following:

findRandom=       1409 => 20032 ms
findSorted=       1310 => 20013 ms
findTwoLoops=     216 => 20197 ms
findTwoLoops+sort=215 => 19917 ms

As you can see the best algorithm is findRandom performed 1409 times in the 20 seconds.

Happy Hacking!!!