use strict;
use warnings;
use Data::Dumper;

my @IDs = qw(Apple Apple Grape Banana Banana);
my @Price = qw(5 5 2 3 4 );
my @Amount = qw(10 15 3 4 4 );

sub uniqjoin { 
	my %seen;
	my $sep=shift;
	return join($sep, grep { !$seen{$_}++ } sort  @_);
}

my ($idx, $id, %h);
#to hash of array
while( ($idx,$id)= each(@IDs) ){
	push @{$h{$id}->{price}} , $Price[$idx];
	push @{$h{$id}->{amount}}, $Amount[$idx];
}
#concatenate arrays with '/'
foreach my $id (keys %h){
	$h{$id}->{price} = uniqjoin( '/', @{$h{$id}->{price}} );
	$h{$id}->{amount} = uniqjoin( '/',  @{$h{$id}->{amount}} );
}

#print
print join(' ', sort keys(%h)) . "\n";
print join(' ' , map{ $h{$_}->{price} } sort keys(%h) ) . "\n";
print join(' ' , map{ $h{$_}->{amount} } sort keys(%h) ) . "\n";