Initial data commit

Task/Symmetric-difference/SQL/symmetric-difference-1.sql

@@ -0,0 +1,14 @@
+create or replace function arrxor(anyarray,anyarray) returns anyarray as $$
+select ARRAY(
+        (
+        select r.elements
+        from    (
+                (select 1,unnest($1))
+                union all
+                (select 2,unnest($2))
+                ) as r (arr, elements)
+        group by 1
+        having min(arr) = max(arr)
+        )
+)
+$$ language sql strict immutable;