An experimental proof of the Monty Hall problem in Ruby. Reference: http://en.wikipedia.org/wiki/Monty_Hall_problem

monty-hall-proof.rb

#!/usr/bin/env ruby

sample_size    = 3000
stay_counter   = 0
switch_counter = 0

sample_size.times do |i|

  # Randomly create a scenario
  winning_door  = [1,2,3].sample
  player_choice = [1,2,3].sample
  revealed_door = ([1,2,3] - [winning_door, player_choice]).sample

  # Determine the winning move
  if player_choice == winning_door
    winning_move = 'Stay'
    stay_counter += 1
  else
    winning_move = 'Switch'
    switch_counter += 1
  end

  # Display the results
  puts "Winning Door: #{winning_door}  " +
       "Player Choice: #{player_choice}  " +
       "Revealed Door: #{revealed_door}  " +
       "Winning Move: #{winning_move}"
end

# Display the aggregate results
puts
puts "Wins by staying   : #{stay_counter}/#{sample_size}"
puts "Wins by switching : #{switch_counter}/#{sample_size}"