парадокс Монти Хола

Сегодня долго спорили с Димкой про парадокс Монти Хола . Было решено написать программку.

Вот она на руби:

def game options = {:size => 10000, :with_change => true}
 times_i_won = 0
 options[:size].times do |index|
   boxes = [:keys, :cabbage, :cabbage].sort_by { rand }
   what_i_pick = boxes[rand(3)]
   if options[:with_change]
     times_i_won += 1 if what_i_pick == :cabbage
   else
     times_i_won += 1 if what_i_pick == :keys
   end
 end
 times_i_won
end

size = 10000

puts "with change    #{game :size => size, :with_change => true} times I won"
puts "without change #{game :size => size, :with_change => false} times I won"

output

with change    6692 times I won
without change 3310 times I won

Вот она на Java от Димы:

package dmitrygusev;

import java.util.Random;

public class Main {

    public static void main(String[] args) {
        Random winGenerator = new Random();
        Random shotGenerator = new Random();
        
        int losses = 0;
        int wins = 0;
        
        for (int n = 0; n < 10000; n++) {
            int win = winGenerator.nextInt(3);
            
            for (int i = 0; i < 3; i++) {
                System.out.print((win == i ? 1 : 0) + "\t");
            }
            
            int shot = shotGenerator.nextInt(3);
            
            System.out.print("shot = " + shot + "\t");
            
            if (win == shot) {
                losses++;
                System.out.println("Loss");
            } else {
                wins++;
                System.out.println("Win");
            }
        }
        
        System.out.println("Losses = " + losses);
        System.out.println("Wins = " + wins);
    }

} 

output

...
0    0    1    shot = 0    Win
0    0    1    shot = 0    Win
0    0    1    shot = 1    Win
0    1    0    shot = 0    Win
Losses = 3316
Wins = 6684