Problem of the Day
A new programming or logic puzzle every Mon-Fri

Welcome back to another awesome week! Today's problem comes to us from @monkbroc

My son has a toy that speaks English words. It has 3 slots for plastic letters. When the slots are full and the letters make up a real word, the toy will read it. The toy comes with 2 of the following letters: D E G M O P, and 1 of each other. So it's possible to spell MOM but not BOB.

Write a program to list all 3 letter words in the English language that can be spelled on that toy.

Most Linux distros come with a built in dictionary or you can find one by searching the internet. Here is one I found for English.

Comments:

• Anonymous - 10 years, 4 months ago

  My solution in Ruby. ruby words.rb

  # words.rb
  class WordMatcher
    def self.match_all_from_dictionary_file(dictionary, letters, word_length)
      word_matcher = WordMatcher.new letters, word_length
      File.open(dictionary).each do |line|
        word = line.chomp
        puts word if word_matcher.matches?(word)
      end
    end
  
    attr_reader :letters, :word_length, :available_letters
  
    def initialize(letters, word_length)
      @letters = letters
      @word_length = word_length
  
      @available_letters = parse_word_to_letters(letters)
    end
  
    def matches?(word)
      word.length == word_length && matches_letters?(word)
    end
  
    def matches_letters?(word)
      word_letters = parse_word_to_letters(word)
      word_letters.all? { |letter, count| enough_letters(letter, count) }
    end
  
    def enough_letters(letter, count)
      (available_letters[letter] || 0) >= count
    end
  
    def parse_word_to_letters(word)
      word_letters = {}
      word.each_char do |letter|
        letter.downcase!
        word_letters[letter] = (word_letters[letter] || 0) + 1
      end
      word_letters
    end
  end
  
  if __FILE__ == $0
    dictionary = (ARGV[0] || "wordlist.txt")
    letters = (ARGV[1] || "abcddeefgghijklmmnooppqrstuvwxyz")
    word_length = (ARGV[2] || '3').to_i
  
    WordMatcher.match_all_from_dictionary_file(dictionary, letters, word_length)
  
  end
  

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