PWC 331

Task 1 Raku done
Task 2 Raku done

Task 1 PL/Perl done
Task 2 PL/Perl done

Task 1 PL/PgSQL done
Task 2 PL/PgSQL done

Task 1 PL/Java done
Task 2 PL/Java done

Task 1 Python done
Task 2 Python done

1 files changed, 48 insertions, 0 deletions

diff --git a/challenge-331/luca-ferrari/plpgsql/ch-2.sql b/challenge-331/luca-ferrari/plpgsql/ch-2.sql
new file mode 100644
index 0000000000..2b70f3e55e
--- /dev/null
+++ b/challenge-331/luca-ferrari/plpgsql/ch-2.sql
@@ -0,0 +1,48 @@
+--
+-- Perl Weekly Challenge 331
+-- Task 2
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-331>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc331;
+
+CREATE OR REPLACE FUNCTION
+pwc331.task2_plpgsql( l text, r text)
+RETURNS boolean
+AS $CODE$
+DECLARE
+	diffs int := 0;
+BEGIN
+	IF l = r THEN
+	   RETURN true;
+	END IF;
+
+	IF length( l ) != length( r ) THEN
+	   RETURN false;
+	END IF;
+
+	WITH
+	lt AS (
+	     SELECT lc::text, row_number() over () as lr
+	     FROM regexp_split_to_table( l, '' ) lc
+	)
+	, rt AS (
+	     SELECT rc::text, row_number() over () as rr
+	     FROM regexp_split_to_table( r, '' ) rc
+	)
+	SELECT count(*)
+	into diffs
+	FROM lt, rt
+	WHERE rr = lr
+	AND lc <> rc
+	;
+
+	IF diffs > 2 THEN
+	   RETURN false;
+	ELSE
+	   RETURN true;
+	END IF;
+
+END
+$CODE$
+LANGUAGE plpgsql;