Data update

Task/Permutations/DuckDB/permutations.duckdb

@@ -0,0 +1,18 @@
+CREATE OR REPLACE FUNCTION permute(lst) as table (
+  WITH RECURSIVE permute(perm, remaining) as (
+    -- base case
+    SELECT
+        [] as perm,
+        lst as remaining
+    UNION ALL
+    -- recursive case: add one element from remaining to perm and remove it from remaining
+    SELECT
+        (perm || [element]) AS perm,
+         (remaining[1:i-1] || remaining[i+1:]) AS remaining
+    FROM (select *, unnest(remaining) AS element, generate_subscripts(remaining,1) as i
+          FROM permute)
+  )
+  SELECT perm
+  FROM permute
+  WHERE length(remaining) = 0
+);