Data commit

Task/Monty-Hall-problem/Perl/monty-hall-problem.pl

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+#! /usr/bin/perl
+use strict;
+my $trials = 10000;
+
+my $stay = 0;
+my $switch = 0;
+
+foreach (1 .. $trials)
+{
+   my $prize = int(rand 3);
+    # let monty randomly choose a door where he puts the prize
+   my $chosen = int(rand 3);
+    # let us randomly choose a door...
+   my $show;
+   do { $show = int(rand 3) } while $show == $chosen || $show == $prize;
+    # ^ monty opens a door which is not the one with the
+    # prize, that he knows it is the one the player chosen
+   $stay++ if $prize == $chosen;
+    # ^ if player chose the correct door, player wins only if he stays
+   $switch++ if $prize == 3 - $chosen - $show;
+    # ^ if player switches, the door he picks is (3 - $chosen - $show),
+    # because 0+1+2=3, and he picks the only remaining door that is
+    # neither $chosen nor $show
+}
+
+print "Stay win ratio " .  (100.0 * $stay/$trials) . "\n";
+print "Switch win ratio " . (100.0 * $switch/$trials) . "\n";