From: Kyle Schmitt <kyleaschmitt@...>
Date: 2007-05-17T07:50:01+09:00
Subject: Late huffman (quiz 123)

So it's rather late to post this, but I spent the time writing it, so why not?
I was hoping I could get a few pointers also, on making this well..
more ruby like.

Perhaps more efficient, more right, etc.

#huffman encoding by dummies
class Huffman
  def initialize(string)
    @sourcestring=string
    @translationtable=nil
    @encoded=nil
    @prettyencoded=nil
    @decoded=nil
  end
  attr_accessor :sourcestring
  attr_reader :encoded,:translationtable,:decoded,:prettyencoded
  def maketranslationtable()
    @translationtable=Hash.new(0)
    @sourcestring.split('').each{|l|
@translationtable.store(l,@translationtable[l]+1)}
    count=0
    @translationtable.collect{|a| a[0],a[1]=a[1],a[0]}.sort.reverse.each do
      |letter|
      @translationtable.store(letter[1],("1"*count+"0").to_i)
      count+=1
    end
    @translationtable[@translationtable.invert.max[1]]/=10
  end

  def translationtable=(newtranslationtable)
    @translationtable=newtranslationtable if
newtranslationtable.class==@translationtable.class
    puts "with a new translationtable, prettymuch everything needs clearing"
    @sourcestring=nil
    @encoded=nil
    @prettyencoded=nil
    @decoded=nil
  end

  def encoded=(data)
    @encoded=data
    puts "with new encoded data, many thigns need to be cleared"
    @sourcestring=nil
    @prettyencoded=nil
    @decoded=nil
  end

  def encode()
    maketranslationtable() if @translationtable.nil?
    @encoded=@sourcestring.split('').collect{|i| @translationtable[i]}.join
  end
  def decode()
    if @translationtable.nil? then
      puts "Can't decode without a translation table!"
    else
      @decoded=@encoded.clone
      @translationtable.invert.to_a.sort.reverse.each do
        |pair|
        @decoded.gsub!(pair[0].to_s,pair[1])
      end
    end
  end

  def prettyprint(byte=8,bytes=5)
    encode() if @encoded.nil?
    @prettyencoded=""
    @encoded.gsub(/([01]{#{byte}})/){|i| "#{i} "}.split.each_with_index do
      |num,index|
      @prettyencoded+="#{num}#{(index+1)%bytes==0?"\n":' '}"
    end
    @prettyencoded+="\n"
  end

  def to_s()
    prettyprint() if @prettyencoded.nil?
    decode() if @decoded.nil?
    "#{@decoded}\n#{@prettyencoded}"
  end

  private :prettyprint
end


h=Huffman.new(ARGV.join(' '))
puts h