tasks a-s

Task/Power-set/OCaml/power-set-1.ocaml

@@ -0,0 +1,17 @@
+module PowerSet(S: Set.S) =
+struct
+
+  include Set.Make (S)
+
+  let map f s =
+    let work x r = add (f x) r in
+    fold work s empty
+  ;;
+
+  let powerset s =
+    let base = singleton (S.empty) in
+    let work x r = union r (map (S.add x) r) in
+    S.fold work s base
+  ;;
+
+end;; (* PowerSet *)

Task/Power-set/OCaml/power-set-2.ocaml

@@ -0,0 +1 @@
+let subsets xs = List.fold_right (fun x rest -> rest @ List.map (fun ys -> x::ys) rest) xs [[]]