From: Erik Veenstra <erikveen@...>
Date: 2007-01-28T03:30:21+09:00
Subject: Re: Review of code please

Here's a map-reduce-ish [1] solution.

I don't say it's better, or faster, or smaller (memory-wise).
It's just, uh, different...

(Sorry, couldn't resist, again... ;])

gegroet,
Erik V. - http://www.erikveen.dds.nl/

 [1] http://labs.google.com/papers/mapreduce.html

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 WITHOUT THE TOTALS

 File.open("anagrams.txt", "w") do |f|
   File.readlines("/usr/share/dict/words").collect do |word|
     word.chomp.downcase
   end.collect do |word|
     [word.scan(/./).sort, word]
   end.inject({}) do |hash, (base, word)|
     (hash[base] ||= []) << word ; hash
   end.values.reject do |set|
     set.length == 1
   end.collect do |set|
     set.sort
   end.sort_by do |set|
     [-set.length, set]
   end.collect do |set|
     set.join("\t")
   end.each do |line|
     f.puts(line)
   end
 end

----------------------------------------------------------------

 WITH THE TOTALS

 sets =
 File.readlines("/usr/share/dict/words").collect do |word|
   word.chomp.downcase
 end.collect do |word|
   [word.scan(/./).sort, word]
 end.inject({}) do |hash, (base, word)|
   (hash[base] ||= []) << word ; hash
 end.values.reject do |set|
   set.length == 1
 end.collect do |set|
   set.sort
 end.sort_by do |set|
   [-set.length, set]
 end

 largest = sets[0]
 longest = sets.inject{|a, b| a[0].length > b[0].length ? a : b}

 File.open("anagrams.txt", "w") do |f|
   sets.each do |set|
     f.puts(set.join("\t"))
   end
 end

 puts "Total: %s"                                        % 
[sets.length]
 puts "Largest set of anagrams: %s"                      % 
[largest.inspect]
 puts "Longest anagrams: %s at %s characters each"       % 
[longest.inspect, longest[0].length]

----------------------------------------------------------------