Thank you!

Strike out all multiples of 2’s:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Strike out all multiples of 3’s:

2 3 5 7 9 11 13 15 17 19

And so on. Here is a C# code that does exactly that:

private static void PrintPrimesTo(int num) {
            var primes = new bool[num + 1];

            // init candidates
            for (int i = 2; i <= num; i++) { primes[i] = true; }

            // cross-out 2's:
            //   2, 4, 6, 8, 10...
            // cross-out 3's:
            //   9, 12, 15...
            for (int i = 2; (i * i) <= num; i++ ) {
                Console.WriteLine("Crossing out {0}'s to {1}:", i, num);

                for (int j = i * i; j <= num; j = j + i) {
                    Console.WriteLine(" * crossing-out: {0}", j);
                    primes[j] = false;
                }
            }

            Console.WriteLine("Results: prime numbers between 2 and {0}:", num);
            for (int i = 2; i <= num; i++) {
                if (primes[i]) Console.WriteLine(" * {0} ", i);
            }
        }

Sample output from calling PrintPrimesTo(100):

Crossing out 2's to 20:
 * crossing-out: 4
 * crossing-out: 6
 * crossing-out: 8
 * crossing-out: 10
 * crossing-out: 12
 * crossing-out: 14
 * crossing-out: 16
 * crossing-out: 18
 * crossing-out: 20
Crossing out 3's to 20:
 * crossing-out: 9
 * crossing-out: 12
 * crossing-out: 15
 * crossing-out: 18
Crossing out 4's to 20:
 * crossing-out: 16
 * crossing-out: 20
Results: prime numbers between 2 and 20:
 * 2
 * 3
 * 5
 * 7
 * 11
 * 13
 * 17
 * 19

Adding lyrics to your songs

You just need to make sure your mp3 files have “lyrics property” populated.

On your computer, open iTunes, right click on a song and choose “Get Info”. You should see this dialog:

Now click on “Lyrics” tab and add your text.

You can copy and paste lyrics text from websites, such as:

• http://lyrics.wikia.com/Main_Page
  

(Also, if you look around you’ll find software that will automatically add lyrics to all of your songs)

How to view lyrics on iPhone:

Once you’ve added lyrics to your songs and synced your phone, here is how you view it: when the song is playing, simply tab the screen once and it will overlay lyrics over album art!

Character classes []:  Regex inside [] are in different mode and have different syntax. It matches a  single character specified as a list, range or class shortcut.  03[-./]19[-./]76  Will match the above date delimited by a dot or a hyphen.  Inside [] the dot is no longer a meta-character, its matched literally!  Negation Operator ^  f[^u]  matches something with f, followed by any character other then u  Character classes shortcuts  \d [0-9] digit  \D non digit  \w [a-zA-Z0-9_] part of word  \W non word  \s [ \t\n\r\f\v] whitespace  \S non whitespaceAlternation:  | operator is 'or'  Jeff(re|er|izz)y  => Jeffrey, Jeffery, JeffizzyConditionals:  (?if then | else)  if the "if" part is true, "then" expression is attmpted, otherwise  "else" is attempted  (?if then)  else condition is optional, so is the pipe character prefixing itAnchors:  ^  beg of line  $  end of line  \b word boundary  \B non-word boundary  Ruby:  \A begining of a string  \Z end of string (or before newline at the end)  \z end of stringOptional Items:  ? optionally matches a character before it, or you can specify a group() of  characters before it:  colou?r  will match color and colour  4(th)?  will match 4 and 4thRepetitions:  +            s1 or more times  *            0 or more times  ?            1 or 0 times  {n}          match exactly n times  {min, max}   min to max times  {min,}       at least min  {,max}       at most max (ruby)Backreferences:  First matched group ():    sed, vi: \1    ruby: $1    php: $m[1]    python, java: m.group(1)    c#: m.Groups[1]  Group zero is typically the entire matchEscape:  \. will escape dot meta characterMore Info:  http://www.regular-expressions.info/

Design
I’ve considered many different technologies, and I decided to make it into a desktop application that runs on people’s computer instead of my server, because of possible heavvy processing of journal data for graphing and all kinds of liability. So Klimb had the following basic components:

• Hypersonic RDBM Engine
• IzPack Installer (see Klimb reference)
• Java Core, Swing GUI
• JFreeChart graphing library
• Obfiscator Plugin to scramble the source code
• Ant builid scripts
• License-checking module/activator

In about a year after this software was released and I made a little money, I released it under GPL (General Public License) and removed the license-checking code and obfiscation.

Aftermath
I am really glad I did this project, it gave me a chance to improove my Java skills. I got so familiar with Java Swing that I made GUI “by hand”, without any builders or tools. I also discovered many issues people don’t normally think of when they’re writing software, such as license checking, protection against decompilation of byte code, deployment to multiple operating systems, and marketing.

Screenshots

Downloads

• Source Code, from 2/4/2006 (for programmers)
• Klimb Installer (for regular users)

Instructions
After you download the installer, double click on it. If it doesn’t run or Windows thinks its a zip file, it means you don’t have Java installed (JRE, Java Runtime Environment) or JAR-type files are associated with some other program like WinZip. JRE is available for free and you can download it here. Either way, if you just install Sun’s JRE, all of your java software will run faster and Klimb installer will launch on double click. If you do have “java” already installed, I’d replace it with Sun’s version. It will also re-associate JAR files back to JVM.

To be honest, I avoid using Windows as much as I can. I own a couple of really nice Intel Macs and a PC Laptop, that I use primarly for Visual Studio and FreeBSD. So, if you’re on UNIX, or if all else fails, you can launch the installer by typing
[code]
# java -jar InstallKlimb.jar
[/code]
on your terminal.

I hope you enjoy this software, please make post of what you though of it, or about your training experience in general.

Don’t forget to have fun while you train,

-D