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+--
+-- Perl Weekly Challenge 202
+-- Task 2
+--
+-- See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-202/>
+--
+
+CREATE SCHEMA IF NOT EXISTS pwc202;
+
+CREATE OR REPLACE FUNCTION
+pwc202.task2_plpgsql( l int[] )
+RETURNS SETOF int[]
+AS $CODE$
+DECLARE
+ cur int;
+ lft int[];
+ rgt int[];
+ idx int;
+ iter int;
+ prev int;
+BEGIN
+
+ CREATE TEMPORARY TABLE IF NOT EXISTS pwc202
+ ( lft int[], rgt int[], dim int DEFAULT 0 );
+ TRUNCATE pwc202;
+
+
+ FOR idx IN 1 .. array_length( l, 1 ) - 1 LOOP
+ cur := l[ idx ];
+ IF l[ idx + 1 ] > cur THEN
+ CONTINUE;
+ END IF;
+
+ lft := NULL;
+ lft := array_append( lft, cur );
+ FOR iter IN idx + 1 .. array_length( l, 1 ) - 1 LOOP
+ prev := lft[ array_length( lft, 1 ) ];
+ IF l[ iter ] <= prev THEN
+ lft := array_append( lft, l[ iter ] );
+ END IF;
+ EXIT WHEN l[ iter ] > prev;
+ END LOOP;
+
+ rgt := NULL;
+ IF array_length( lft, 1 ) + idx <= array_length( l, 1 ) THEN
+ prev := l[ idx + array_length( lft, 1 ) ];
+ rgt := array_append( rgt, prev );
+ FOR iter IN array_length( lft, 1 ) + idx + 1 .. array_length( l, 1 ) LOOP
+ prev := rgt[ array_length( rgt, 1 ) ];
+ IF l[ iter ] >= prev THEN
+ rgt := array_append( rgt, l[ iter ] );
+ END IF;
+ EXIT WHEN l[ iter ] < prev;
+ END LOOP;
+ END IF;
+
+ INSERT INTO pwc202
+ VALUES( lft, rgt, array_length( lft, 1 ) + array_length( rgt, 1 ) );
+
+
+
+ END LOOP;
+
+ RETURN QUERY SELECT array_cat( p.lft, p.rgt )
+ FROM pwc202 p
+ ORDER BY dim DESC
+ LIMIT 1;
+END
+$CODE$
+LANGUAGE plpgsql;