Task 2 PostgreSQL done

1 files changed, 34 insertions, 0 deletions

diff --git a/challenge-138/luca-ferrari/postgresql/ch-2.sql b/challenge-138/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..6b6c49cc89
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+++ b/challenge-138/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,34 @@
+CREATE OR REPLACE FUNCTION
+  f_split_numbers( n int default 9801 )
+  RETURNS int
+AS $CODE$
+  DECLARE
+  sqrt int := sqrt( n );
+  digits int[] := regexp_split_to_array( n::text, '' );
+  aggregation int := 0;
+  sum_left int := 0;
+  sum_right int := 0;
+BEGIN
+  RAISE DEBUG 'Operating for % (sqrt = %)', n, sqrt;
+
+  FOR aggregation IN 1 .. length( n::text ) LOOP
+    RAISE DEBUG 'Aggregation index %', aggregation;
+
+    SELECT array_to_string( digits[1:aggregation], '' )::int
+           , sum( r )
+      FROM ( SELECT unnest( digits[ aggregation + 1: length( n::text ) ] ) AS r ) rr
+      INTO sum_left, sum_right;
+
+    RAISE DEBUG '% + %', sum_left, sum_right;
+
+    IF ( sum_left + sum_right ) = sqrt THEN
+      RETURN 1;
+    END IF;
+  END LOOP;
+
+  RETURN 0;
+END
+  $CODE$
+  LANGUAGE plpgsql;
+
+