use strict;
use warnings;
use File::Basename qw( fileparse );

my %seen;
while (<DATA>) {
    (undef, my $path) = fileparse( $_ );
    print "$path\n" unless $seen{$path}++;
}

print "="x70,"\n";

foreach my $key (keys %seen){
    print "$key\n" if 1 == scalar grep { /\Q$key/ } keys %seen;
}
__DATA__
testing123/
foobar/
helloworld/
helloworld/r1/
helloworld/r1/helloworld-5-0.noarch.rpm
helloworld/r1/testfile23.txt
helloworld/r1/tomcat-7.0.27.rpm
helloworld/r2/
helloworld/r2/helloworld-2-0.noarch.rpm
helloworld/r2/testfile12.txt
helloworld/r2/tomcat-5.0.52.rpm
hellotest/