From: Mark Woodward <markonlinux@...>
Date: 2007-01-27T22:25:05+09:00
Subject: Re: Review of code please

Well!!,

On Sat, 27 Jan 2007 23:38:30 +1100, Mark Woodward wrote:

> Hi all,
> 
> I'm hoping for some critique of the code below. 
> It works but is slow and probably not 'the ruby way'
> 
> ---------------------------------------------------------
> # Anagrams
> #
> # Purpose: find all anagrams in /usr/share/dict/words
> #          for 4 letter words (length 5 because of \n)
> 
> # path to the word file
> filename = "/usr/share/dict/words"
> 
> # check file exists and is readable
> if File.file?(filename) && File.readable?(filename) then
>   dict_words = []
>   all_anagrams = {}
> 
>   open(filename).each do |dict_word|
>     if dict_word.length == 5 then
>       dict_words << dict_word.chomp.strip
>     end
>   end
>   
>   wrds = dict_words
> 
>   dict_words.each do |wrd|
>     current_wrd = wrd.split(//).sort.join
> 
>     anagrams = []
> 
>     wrds.each do |w|
>       if wrd != w then
>         if not current_wrd == w.split(//).sort.join then
>           next
>         end
>         anagrams.push(w)
>       end
>     end
>   
>     if not anagrams.empty? then
>       all_anagrams[wrd] = anagrams
>     end
>   end
> 
>   p all_anagrams
> 
> end
> ---------------------------------------------------------
> 
> thanks,

I just found a solution here:
http://www.joeygibson.com/blog/tech/ruby/index.html

that is exponentially faster than mine and finds all anagrams not just 4
letter words! I just need to understand it now.

---------------------------------------------------------
words = IO.readlines("/usr/share/dict/words")

anagrams = Hash.new([])

words.each do |word|
    base = Array.new
    word.chomp!.downcase!

    word.each_byte do |byte|
        base << byte.chr
    end

    base.sort!

    anagrams[base.to_s] |= [word]
end

# Find the anagrams by eliminating those with only one word
anagrams.reject! {|k, v| v.length == 1}

values = anagrams.values.sort do |a, b|
    b.length <=> a.length
end

File.open("anagrams.txt", "w") do |file|
    values.each do |line|
        file.puts(line.join(", "))
    end
end

largest = anagrams.keys.max do |a, b|
    a.length <=> b.length
end

puts "Total: #{anagrams.length}" #
puts "Largest set of anagrams: #{values[0].inspect}" # 
print "Longest anagram: #{anagrams[largest].inspect} " # 
puts "at #{largest.length} characters each"
---------------------------------------------------------

-- 
Mark