README.md

Fallout 3 terminal hacker

Enter all the words as arguments on the command line,

user$ fallout_3 clustered mentioned stationed convinces eliminate convinced \
      convicted criminals challenge chemicals considers carriages cardinals \
      rearguards hurriedly continued consisted messianic gladiator chemistry
  0:  clustered
  1:  mentioned
  2:  stationed
  3:  convinces
  4:  eliminate
  5:  convinced
  6:  convicted
  7:  criminals
  8:  challenge
  9:  chemicals
  10: considers
  11: carriages
  12: cardinals
  13: rearguard
  14: hurriedly
  15: continued
  16: consisted
  17: messianic
  18: gladiator
  19: chemistry
fallout_3> 

You may then enter in a number (or the word itself) followed by another number, which is the number of matching letters. As you enter in more words, the list of words you can enter diminishes. Once the solver is confident that it has found the right word, it quits.

fallout_3

require 'pp'

class Puzzle
  attr_reader :words

  def initialize(words = [])
    @words = words
  end

  def add_clue(word, num_matching_chars)
    @clues ||= {}
    @clues[word] = num_matching_chars
  end

  def potential_solutions
    # Set of potential solutions is the set of words in the original vocabulary
    # (@words) which, for each clue, have the same number of letters in common
    # with that previous guess as that guess had with the correct password. So,
    # if "conductor" had 3 letters in common with the solution, then
    # "confluence" could be a solution but "condiment" could not because it has
    # too many letters in common with the clue.
    return self.words if @clues.nil? or @clues.empty?

    self.words.select do |word|
      @clues.all?{|k, v| k != word and num_matching(k, word) == v}
    end
  end

  private

  def num_matching(a, b)
    # a.each_with_index do |c, i|
    #   matches += 1 if c == b[i]
    # end

    # Let's make this function as absurd as possible why don't we....
    a.split(//).zip(b.split(//)).map{|x, y| x == y ? 1 : 0}.reduce(:+)
  end
end

# Main -------------------------------------------------------------------------

def main()
  puzzle = Puzzle.new(ARGV)
  p puzzle
  p puzzle.potential_solutions

  until puzzle.potential_solutions.count <= 1
    puts "Potential solutions:"
    puzzle.potential_solutions.each_with_index do |s, i|
      puts("  %2d: #{s}" % i)
    end

    print "Choose a guess: "
    guess = $stdin.gets.chomp
    print "What was the response? "
    matches = $stdin.gets.to_i

    puzzle.add_clue(guess, matches)
  end

  case puzzle.potential_solutions.count
  when 1
    puts "Solution found: #{puzzle.potential_solutions.first}"
  when 0
    puts "No solutions found! Try again."
  end
end

if __FILE__ == $0
  main
end

# vim: set ft=ruby: