use strict;
use warnings 'all';
use Test::More qw( no_plan );
require "doors.perl";
 
 # Initialise array of doors.
 my @doors = init_doors();
 is($doors[1], 'Closed', 'Door one should be closed');
 is($doors[100], 'Closed', 'Door 100 should be closed');
 
 toggle_door(\$doors[1]);
 is($doors[1], 'Open', 'Door one should be closed');
 toggle_door(\$doors[1]);
 is($doors[1], 'Closed', 'Door one should be open');
 
 
 my @answer = loop_through_doors();
 
 # Doors open are: 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100
 is($answer[1], 'Open');
 is($answer[4], 'Open');
 is($answer[9], 'Open');
 is($answer[16], 'Open');
 is($answer[25], 'Open');
 is($answer[36], 'Open');
 is($answer[49], 'Open');
 is($answer[64], 'Open');
 is($answer[81], 'Open');
 is($answer[100], 'Open');
 
 # Check some of the other doors are closed.
 is($answer[2], 'Closed');
 is($answer[3], 'Closed');
 is($answer[50], 'Closed');
 is($answer[99], 'Closed');
 
##</code><code>##

use strict;
use warnings;
 
 sub init_doors
 {
   my @doors;
   for my $i (1 .. 100)
   {
     $doors[$i] = 'Closed';
   }
   return(@doors); 
 }
 
 sub toggle_door
 {
   my $door_ref = shift;
   if( $$door_ref eq 'Closed' )
   {
     $$door_ref = 'Open';
   } else {
     $$door_ref = 'Closed';
   }
   return $$door_ref; 
 }
 
 sub loop_through_doors
 {
  my @doors = init_doors();
   for my $pass (1 .. 100)
   {
     for my $visit (1 .. 100)
     {
       if (($visit % $pass) == 0)
       {
          toggle_door(\$doors[$visit]);
       }
     }
   }
 
   return(@doors); 
 }
 
 1;