MasterMind game: computer-vs-computer

mastermind.rb

# MasterMind Ruby implementation
# by Simon Stastny
# June 23, 2012

#GAME SETUP
ALPHABET = "12345678"
SIZE = 4
COLORS = 6
USED_ALPHABET = ALPHABET.slice(0..COLORS-1)


#GAME RULES IMPLEMENTATION
def white_pegs (solution, proposed)
  pegs = 0
  SIZE.times {|c| if solution[c] == proposed[c]; pegs+=1; end }
  return pegs
end

def black_pegs (solution, proposed)
  pegs = 0
  USED_ALPHABET.split("").collect { |x| pegs += [proposed.scan(x).length,solution.scan(x).length].min }
  return pegs - white_pegs(solution, proposed)
end

def is_correct?
  return $wpegs == SIZE
end

def is_guess_valid?(guess)
  return guess.size == SIZE && guess.split("").all? { |x| USED_ALPHABET.scan(x).size > 0 } 
end

#GENERATING SOLUTIONS
def generate
  (0...SIZE).map{ USED_ALPHABET.split("").to_a[rand(USED_ALPHABET.size)] }.join
end

#GUESSING
#PC

def let_computer_guess
  proposed = generate
  
  while not is_guess_possible? proposed
    proposed = generate
  end
  
  return proposed
end

def is_guess_possible?(guess)
  if $black_map.has_key?(guess)    
    return false
  end
  
  if $black_map.size > 0
    return $black_map.all? { |k,v| black_pegs(guess, k) == v } && $white_map.all? { |k,v| white_pegs(guess, k) == v } 
  else
    return true
  end
end

#HUMAN
def let_player_guess
  puts "---------------"
  puts "Yout next guess:"
  
  proposed = gets.chomp
  
  while not is_guess_valid? proposed
    puts "Invalid answer. Answer again:"
    proposed = gets.chomp
  end
  
  return proposed
end

def get_white_score
  puts "Tell how many white pegs: "
  gets.chomp.to_i
end

def get_black_score
  puts "Tell how many black pegs: "
  gets.chomp.to_i
end


def play
  proposed = $get_guess.call
  
  puts "---------------"
  puts "guess: " + proposed
  
  $wpegs = $score_white.call($solution,proposed)
  $bpegs = $score_black.call($solution,proposed)
  
  $black_map.store(proposed, $bpegs)
  $white_map.store(proposed, $wpegs)
  
  puts "white pegs: " + $wpegs.to_s
  puts "black pegs: " + $bpegs.to_s
  puts "\n\n"
  
  if is_correct?
    puts "Solution is " + proposed + "."
  end
  
  return proposed
end

#GAME ------------------------------------------------------------
$black_map = {}
$white_map = {}

puts "Welcome to MasterMind"
puts "---------------\n"
puts "\nWho is solver today? (HUMAN or PC) "
$solver = gets.chomp
puts "\nWho is code maker today? (HUMAN or PC)? "
$maker = gets.chomp
puts "\n\n\n"

if $maker == "PC"
  $solution = generate
end

i = 0

$get_guess = lambda { if $solver == "PC"; return let_computer_guess; else return let_player_guess; end}
$score_white = lambda { |solution,proposed| if $maker == "HUMAN"; return get_white_score; else return white_pegs(solution,proposed); end}
$score_black = lambda { |solution,proposed| if $maker == "HUMAN"; return get_black_score; else return black_pegs(solution,proposed); end}

#GAME LOOP
loop do
  i+=1;
  puts "Round " + i.to_s
  play
  break if is_correct?
end