This could probably be simplified a little:
#! perl -sw
use strict;
use Data::Dump qw[ pp ];
my $h= {
(4,-1),
(2,6),
(6,4),
(3,5),
(5,-1),
(99,-1),
};
my %invert;
push @{ $invert{ $h->{ $_ } } }, $_ for keys %{ $h };
my %hh;
for( @{ $invert{ -1 } } ) {
my $ref = { $_, -1 };
while( exists $invert{ $_ } ) {
my $key = pop @{ $invert{ $_ } };
$ref = { $key, $ref };
delete $invert{ $_ } unless @{ $invert{ $_ } };
$_ = $key;
}
my( $key, $value ) = each %$ref;
$hh{ $key } = $value;
}
pp \%hh;
__END__
c:\test>755232
{
2 => { 6 => { 4 => -1 } },
3 => { 5 => -1 },
9 => -1
}
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
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