Almost no change: 
#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my @bigArray = qw(brown red+green blue+yellow black red+white purple+o
+range+gray);
my %hash;

for (@bigArray) {
    my @keys = split /\+/;
    my $ptr = \%hash;
    $ptr = $ptr->{$_} ||= {} for @keys[0..$#keys-1]; # work done here
    $ptr->{$keys[-1]} = 1;
}

print Dumper(\%hash);
__END__

[download]
Output: 
$VAR1 = {
          'blue' => {
                      'yellow' => 1
                    },
          'purple' => {
                        'orange' => {
                                      'gray' => 1
                                    }
                      },
          'brown' => 1,
          'black' => 1,
          'red' => {
                     'green' => 1,
                     'white' => 1
                   }
        };

[download]
Key change vs the code I posted in your previous node is use of ||= vs = so that a key is only assigned an anonymous hashref when it doesn't already have a value. (Which isn't quite right; it's only assigned a hashref when it doesn't have a true value, but that will work so long as any value a key can ever have is true. Here they can only be either hashrefs or the value 1, both of which are indeed true.)

Makeshifts last the longest.

In reply to Re: hash tree by Aristotle
in thread hash tree by hotshot

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