--
-- Perl Weekly Challenge 263
-- Task 2
-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-263>
--

CREATE SCHEMA IF NOT EXISTS pwc263;

CREATE OR REPLACE FUNCTION
pwc263.task2_plperl( int[], int[] )
RETURNS TABLE( item int, qty int )
AS $CODE$

   my ( $items1, $items2 ) = @_;
   my $q = {};

   for my $pair ( $items1->@*, $items2->@* ) {
       $q->{ $pair->[ 0 ] } += $pair->[ 1 ];
   }


   return_next( { item => $_, qty => $q->{ $_ } } )  for ( sort keys $q->%* );
   return undef;
$CODE$
LANGUAGE plperl;