use strict;
use warnings;

my (%plus, %minus);
while (<DATA>) {
	my ($fruit, $sign) = split;
	if ($sign eq '+') {
		$plus{$fruit} = 1;
	} else {
		$minus{$fruit} = 1;
	}
}

print "Positives are : ", (map "$_, ", keys %plus), "\n";
print "Negatives are : ", (map "$_, ", keys %minus), "\n";

__DATA__
apple    +
cherry    -
cherry    +
peach    +
banana    -

##</code><code>##

$ perl plus_minus.pl
Positives are : peach, cherry, apple,
Negatives are : banana, cherry,