Task 2 plperl

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-208/luca-ferrari/postgresql/ch-2.plperl b/challenge-208/luca-ferrari/postgresql/ch-2.plperl
new file mode 100644
index 0000000000..6e2f8666fc
--- /dev/null
+++ b/challenge-208/luca-ferrari/postgresql/ch-2.plperl
@@ -0,0 +1,39 @@
+--
+-- Perl Weekly Challenge 208
+-- Task 2
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-208/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc208;
+
+/*
+testdb=> select pwc208.task2_plperl( array[ 1,2,2,4,5]::int[] );
+       task2_plperl       
+--------------------------
+ (2,"Duplicated value 2")
+ (3,"Missing value 3")
+(2 rows)
+
+*/
+CREATE OR REPLACE FUNCTION
+pwc208.task2_plperl( int[] )
+RETURNS TABLE( v int, d text )
+AS $CODE$
+  my ( $list ) = @_;
+  my %results;
+
+  my ( $min, $max ) = ( sort $list->@* )[0, -1];
+  for my $needle ( $min .. $max ) {
+      $results{ $needle } += scalar grep { $_ == $needle } $list->@*;
+  }
+
+  for ( sort keys %results ) {
+    next if $results{ $_ } == 1;
+    return_next( { v => $_, d => "Missing value $_" } ) if ( $results{ $_ } == 0 );
+    return_next( { v => $_, d => "Duplicated value $_" } ) if ( $results{ $_ } > 1 );
+  }
+
+return undef;
+ 
+$CODE$
+LANGUAGE plperl;