goats

gistfile1.rb

#!/usr/bin/env ruby
class Array
  def random; self[rand(self.length)]; end
end

# extended by actual player classes
class Player
  attr_reader :name

  def initialize(name)
    @name = name
  end

  def happy_with_prize?
    @prize != :goat
  end

  def say(text)
    STDOUT.puts "Plyr: " + text
  end

  def receive(prize)
    @prize = prize
  end

  def pick_first_door(doors)
    @first_pick = doors.random
  end
end

class SwitchPlayer < Player
  def pick_first_door(door_count)
    door = super
    say "Gee, Bob... I guess mah first pick's gotta be door %d" % door
    door
  end

  # always switch
  def pick_final_door(doors_remaining)
    say "Welp, Bob, mah paw told me I oughtta what with the switchin'."
    (doors_remaining - [@first_pick]).first
  end
end

class StayPlayer < Player
  def pick_first_door(door_count)
    door = super
    say "AHM A GONNA PICK DOOR %s" % (%w(ZERUH WUN TEW)[door] || door)
    door
  end

  # always stay
  def pick_final_door(doors_remaining)
    say "AH AIN'T GONNA SWITCH, BOBBY"
    @first_pick
  end
end

class Host
  def initialize(*args)
    @door_with_prize, @player, @door_count = *args
  end

  def run_show!
    say "Welcome to THE PRICE ARE GOAT!"

    say "Pick a door, %s." % @player.name
    first_pick = @player.pick_first_door(doors)
    say "Great choice, %s. You picked door #%d" % [@player.name, first_pick]

    say "Time for the reveal!"
    doors_to_open = (doors - [first_pick] - [@door_with_prize])
    doors_to_open -= [doors_to_open.random] if first_pick == @door_with_prize
    say "Vanna, please open: " + (doors_to_open * ', ')
    say "It's %s!" % [doors_to_open.length == 1 ? 'a goat' : '%d goats' % doors_to_open.length]

    say "Now, do you want to keep your choice, or will you switch?"
    final_pick = @player.pick_final_door(doors - doors_to_open)
    say "Okay, %s! Let's see if you're a thousandthousandaire!" % @player.name
    say "Vanna, please open door #%d" % final_pick

    if final_pick == @door_with_prize
      @player.receive(:million_male_deer)
      say "DAS GELD! A WINRAR IS U!"
    else
      @player.receive(:goat)
      say "FAIL! Here's your goat, %s! Enjoy." % @player.name
    end
  end

  def doors
    (0...@door_count).to_a
  end

  def say(text)
    STDOUT.puts "Host: " + text
  end
end

def win_ratio(won_games, lost_games)
  total_games = won_games + lost_games
  '%d%% games won' % (won_games.to_f / total_games * 100)
end

DOOR_COUNT = 3
GAME_COUNT = 1000

win_counts = {}
{'Cletus' => SwitchPlayer, 'Mildred' => StayPlayer}.each do |name, klass|
  win_counts[name] = 0
  GAME_COUNT.times do
    player = klass.new(name)
    Host.new(rand(DOOR_COUNT), player, DOOR_COUNT).run_show!
    win_counts[name] += 1 if player.happy_with_prize?
    puts
  end
end

puts "Summary:\n"
win_counts.each do |name, count|
  puts "  " + name
  puts "    %s%% of games won\n" % (100.0 * count / GAME_COUNT)
end