Finds words of a given length that are made from the given letters. Helps solve puzzles in the "Four Pictures, One Word" game.

puzzle.rb

#!/usr/bin/envy ruby
#
# Finds words of a given length that are made from the given letters.
# Helps solve "Four Pictures, One Word" puzzles.
# @author Anson Hoyt

require 'optparse'

# Parse command line arguments
def parse(args)
  options = {}
  opts = OptionParser.new do |opts|
    opts.banner = "Usage: #{$0} letters length"

    opts.on(:REQUIRED, "--length LENGTH", "Length of the word") do |length|
      options[:length] = length
    end

    opts.on(:REQUIRED, "-L", "--letters LETTERS", "Letters which spell the word") do |letters|
      options[:letters] = letters
    end

    opts.on_tail("-h", "--help", "Show this message") do
      puts opts
      exit
    end
  end

  opts.parse!
  abort opts.banner unless options[:letters] # Require file to be specified
  options
end # parse()

options = parse(ARGV)

letters = options[:letters]
length = options[:length]
matches = []

words = (`cat /usr/share/dict/words`).split("\n")

words.grep(/^[#{letters}]{#{length}}$/).each {|word|
  unmatched_letters = letters.clone

  isMatch = true
  word.chars.each {|letter|
    i = unmatched_letters.index(letter)
    if i
      unmatched_letters[i] = ' '
    else
      # puts "#{word}: can't find '#{i}' in #{unmatched_letters}"
      isMatch = false
    end
  }
  matches << word if isMatch
}

puts "Looked through #{words.count} words to find every #{length}-letter word spelt with '#{letters}'"

matches.each_slice(4) {|a|
  puts "#{a[0]}\t#{a[1]}\t#{a[2]}"
}