Merge branch 'master' of https://github.com/manwar/perlweeklychallenge-club

4 files changed, 184 insertions, 0 deletions

diff --git a/challenge-191/luca-ferrari/postgresql/ch-1.plperl b/challenge-191/luca-ferrari/postgresql/ch-1.plperl
new file mode 100644
index 0000000000..321ae4b3a8
--- /dev/null
+++ b/challenge-191/luca-ferrari/postgresql/ch-1.plperl
@@ -0,0 +1,36 @@
+-- Perl Weekly Challenge 191
+-- Task 1
+
+CREATE SCHEMA IF NOT EXISTS pwc191;
+
+
+/*
+testdb=> select * from pwc191.task1_plperl( ARRAY[1,2,3,6]::int[] );
+ task1_plperl 
+--------------
+            1
+
+*/
+CREATE OR REPLACE FUNCTION
+pwc191.task1_plperl( int[] )
+RETURNS int
+AS $CODE$
+   my ($l) = @_;
+
+   my $max = 0;
+
+   # compute the max element
+   for ( $l->@* ) {
+       $max = $_ if ( $max < $_ );
+   }
+
+   # iterate on all elements and see
+   # if one of the is doubly greater than the max
+   for ( $l->@* ) {
+       next if $_ == $max;
+       return -1 if $_ * 2 > $max;
+   }
+
+   return 1;
+$CODE$
+LANGUAGE plperl;
diff --git a/challenge-191/luca-ferrari/postgresql/ch-1.sql b/challenge-191/luca-ferrari/postgresql/ch-1.sql
new file mode 100644
index 0000000000..a1378c4676
--- /dev/null
+++ b/challenge-191/luca-ferrari/postgresql/ch-1.sql
@@ -0,0 +1,33 @@
+-- Perl Weekly Challenge 191
+-- Task 1
+
+CREATE SCHEMA IF NOT EXISTS pwc191;
+
+CREATE OR REPLACE FUNCTION
+pwc191.task1_plpgsql( l int[] )
+RETURNS int
+AS $CODE$
+DECLARE
+	current_max int;
+	wrong int := 0;
+BEGIN
+	-- compute the max
+	SELECT max( v )
+	INTO   current_max
+	FROM unnest( l ) v;
+
+	SELECT count(*)
+	INTO   wrong
+	FROM unnest( l ) v
+	WHERE ( v * 2 ) > current_max
+	AND   v <> current_max;
+
+	IF wrong > 0 THEN
+	   RETURN -1;
+        ELSE
+          RETURN 1;
+        END IF;
+
+END
+$CODE$
+LANGUAGE plpgsql;
diff --git a/challenge-191/luca-ferrari/postgresql/ch-2.plperl b/challenge-191/luca-ferrari/postgresql/ch-2.plperl
new file mode 100644
index 0000000000..98cfcd741b
--- /dev/null
+++ b/challenge-191/luca-ferrari/postgresql/ch-2.plperl
@@ -0,0 +1,44 @@
+-- Perl Weekly Challenge 191
+-- Task 2
+
+CREATE SCHEMA IF NOT EXISTS pwc191;
+
+CREATE OR REPLACE FUNCTION
+pwc191.task2_plperl( int )
+RETURNS int
+AS $CODE$
+   use List::Permute::Limit qw(permute_iter permute);
+
+   my ($n) = @_;
+   my $cute_counter = 0;
+   my @l = ( 1 .. $n );
+   
+   my @permutations = permute( items => [ @l ], nitems => $n );
+   for my $current_list ( @permutations ) {
+
+       my $is_cute = 1;		 
+       for my $i ( 0 .. $current_list->@* ) {
+
+       	   if ( $current_list->[ $i ] % ( $i + 1 ) != 0 ) {
+	      $is_cute = 0;
+	      last;
+	   }
+       }
+
+       $cute_counter++ if ( $is_cute );
+
+       $is_cute = 1;		 
+       for my $i ( 0 .. $current_list->@* ) {
+
+       	   if ( ( $i + 1 ) % $current_list->[ $i ]  != 0 ) {
+	      $is_cute = 0;
+	      last;
+	   }
+       }
+
+       $cute_counter++ if ( $is_cute );
+   }
+
+   return $cute_counter;
+$CODE$
+LANGUAGE plperlu;
diff --git a/challenge-191/luca-ferrari/postgresql/ch-2.sql b/challenge-191/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..7b4755b34c
--- /dev/null
+++ b/challenge-191/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,71 @@
+-- Perl Weekly Challenge 191
+-- Task 2
+
+CREATE SCHEMA IF NOT EXISTS pwc191;
+
+CREATE OR REPLACE FUNCTION
+pwc191.task2_plpgsql( n int )
+RETURNS int
+AS $CODE$
+DECLARE
+	cute_counter int := 0;
+	i int;
+	src int[];
+	permutation int[];
+	is_cute bool;
+BEGIN
+
+	FOR i IN 1 .. n LOOP
+	    src = src || i;
+	END LOOP;
+
+
+
+	FOR permutation IN
+	with recursive
+	data as (select src as arr),
+        keys as (select generate_subscripts(d.arr, 1) as rn from data d),
+        cte  as (
+           select d.arr initial_arr, array[d.arr[k.rn]] new_arr, array[k.rn] used_rn
+           from data d
+           cross join keys k
+           union all
+           select initial_arr, c.new_arr || c.initial_arr[k.rn], used_rn || k.rn
+           from cte c
+           inner join keys k on not (k.rn = any(c.used_rn))
+    )
+    select new_arr
+    from cte
+    WHERE array_length( new_arr, 1 ) = n
+    LOOP
+
+	 is_cute := 1;
+	 FOR i IN 1 .. array_length( permutation, 1 ) LOOP
+	 	 IF permutation[i] % i <> 0  THEN
+		    is_cute = false;
+		    EXIT;
+		 END IF;
+	 END LOOP;
+
+	 IF is_cute THEN
+	    cute_counter := cute_counter + 1;
+	 END IF;
+
+	 is_cute := 1;
+	 FOR i IN 1 .. array_length( permutation, 1 ) LOOP
+	 	 IF i % permutation[i] <> 0  THEN
+		    is_cute = false;
+		    EXIT;
+		 END IF;
+	 END LOOP;
+	 IF is_cute THEN
+		 cute_counter := cute_counter + 1;
+	 END IF;
+
+    END LOOP;
+
+
+RETURN cute_counter;
+END
+$CODE$
+LANGUAGE plpgsql;