Code Golf: Numeric Diamonds

0 comments

Here is my submission for the Numeric Diamonds challenge. Code size: 219 bytes.

[9,36,100].each{|n|s=Math.sqrt(n).to_i
w=n.to_s.size.to_i
a=[]
j=s+s-1
j.times{a<<[" "*w]*j}
x=0
y=s-1
f=x
g=y
1.upto(n){|t|a[x][y]=t.to_s.rjust w
t%s<1 ?(x=f+1;f=x;y=g-1;g=y):(x+=1;y+=1)}
a.each{|r|puts r.join.rstrip}}

Tagged: ruby, code golf

Parsing an RSS feed with Ruby

7 comments

Parsing an RSS feed is insanely simple with Ruby. Two lines is all it takes. . .

require 'rss'
rss = RSS::Parser.parse(open('http://www.travisonrails.com/feed/posts').read, false)

Now you'll have an Array of the results, so you can do something like:

rss.items.each { |i| puts "#{i.title} - #{i.date}" }

Tagged: tutorial, rss, ruby

Generate random text with Ruby

13 comments

UPDATE: Changed the generate_password method slightly based on commenter Dave Burt's suggestion.

I'm working on a project where the user can reset their password if they've forgotten it. So, I need to generate a random password and email it to them so they can login and change it. Fortunately, I found this neat little Ruby snippet that will generate random text of a given length:

def generate_password(length=6)
  chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ23456789'
  password = ''
  length.times { |i| password << chars[rand(chars.length)] }
  password
end

Some examples:

generate_password
>> U48ydn

generate_password(10)
>> QzWXdAkDy5

Tagged: tutorial, script, ruby

Code Golf: Roman to Decimal

0 comments

Here is my submission for the Roman to Deciman challenge. Code size: 121 bytes.

v={'I',1,'V',5,'X',10,'L',50,'C',?d,'D',500,'M',1000}
y=q=0
gets.chop.split('').each{|n|j=v[n]
y+=j-(q<j ?q*2:0)
q=j}
p y

Tagged: ruby, code golf

Fore!

0 comments

Shawn recently turned me onto a really cool site: Code Golf. Every week (or so) they post a coding challenge. The challenges themselves aren't overly difficult (well, most aren't). The real challenge is to complete the challenge with as little code as possible. . . literally. Your code submissions are first evaluated to determine if they work like they should, then they count how many bytes your program takes up. The shortest program for each accepted language (Perl, PHP, Python, and Ruby) gets 10,000 points, with each longer program getting points based on their size relative to the winning submission.

I've only been able to complete two challenges so far. Both have fallen around the middle of the group with regards to size. I'm not sure I'll ever know the shortcuts to get my 228 byte program down to 102 bytes! It is a great excuse for exercising your brain, though.

UPDATE: I've started posting my submissions to the challenges that I've been able to complete. Just look for posts tagged with code golf.

Tagged: ruby, code golf