From 0b34796d4ac05eb356385f08c095b2db476bc6ff Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 28 Nov 2022 11:10:34 +0100
Subject: Task 2 plpgsql

---
 challenge-193/luca-ferrari/postgresql/ch-2.sql | 84 ++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 challenge-193/luca-ferrari/postgresql/ch-2.sql

diff --git a/challenge-193/luca-ferrari/postgresql/ch-2.sql b/challenge-193/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..7a9e8be234
--- /dev/null
+++ b/challenge-193/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,84 @@
+-- Perl Weekly Challenge 193
+-- Task 2
+
+CREATE SCHEMA IF NOT EXISTS pwc193;
+
+CREATE OR REPLACE FUNCTION
+pwc193.task2_plpgsql( s text )
+RETURNS text
+AS $CODE$
+DECLARE
+	c char;
+	pre int;
+	cur int;
+
+	count_all int;
+	count_odd int;
+BEGIN
+	CREATE TEMPORARY TABLE IF NOT EXISTS translations( l char, i int DEFAULT 0 );
+	TRUNCATE translations;
+
+	INSERT INTO translations
+	VALUES
+	  ( 'a', 0 )
+	, ( 'b', 1 )
+	, ( 'c', 2 )
+	, ( 'd', 3 )
+	, ( 'e', 4 )
+	, ( 'f', 5 )
+	, ( 'g', 6 )
+	, ( 'h', 7 )
+	, ( 'i', 8 )
+	, ( 'j', 9 )
+	, ( 'k', 10 )
+	, ( 'l', 11 )
+	, ( 'm', 12 )
+	, ( 'n', 13 )
+	, ( 'o', 14 )
+	, ( 'p', 15 )
+	, ( 'q', 16 )
+	, ( 'r', 17 )
+	, ( 's', 18 )
+	, ( 't', 19 )
+	, ( 'u', 20 )
+	, ( 'v', 21 )
+	, ( 'x', 22 )
+	, ( 'y', 23 )
+	, ( 'z', 24 );
+
+
+	CREATE TEMPORARY TABLE IF NOT EXISTS result( v int );
+	TRUNCATE result;
+
+	FOR c IN SELECT regexp_split_to_table( s, '' ) LOOP
+	    SELECT i
+	    INTO cur
+	    FROM translations
+	    WHERE l = c;
+
+	    IF pre IS NOT NULL THEN
+	       INSERT INTO result
+	       SELECT cur - pre;
+	    END IF;
+
+	    pre := cur;
+	END LOOP;
+
+
+	SELECT count( * )
+	INTO count_all
+	FROM result;
+
+	SELECT count(*)
+	INTO count_odd
+	FROM result
+	WHERE V % 2 <> 0;
+
+	IF count_all <> count_odd THEN
+	   RETURN NULL;
+	ELSE
+	  RETURN s;
+	END IF;
+END
+$CODE$
+LANGUAGE plpgsql;
-- 
cgit