Data commit

Task/Deceptive-numbers/OCaml/deceptive-numbers.ocaml

@@ -0,0 +1,17 @@
+let modpow m =
+  let rec loop p b e =
+    if e land 1 = 0
+    then if e = 0 then p else loop p (b * b mod m) (e lsr 1)
+    else loop (p * b mod m) (b * b mod m) (e lsr 1)
+  in loop 1
+
+let is_deceptive n =
+  let rec loop x =
+    x * x <= n && (n mod x = 0 || n mod (x + 4) = 0 || loop (x + 6))
+  in
+  n land 1 <> 0 && n mod 3 <> 0 && n mod 5 <> 0 && loop 7 &&
+  modpow n 10 (pred n) = 1
+
+let () =
+  Seq.(ints 49 |> filter is_deceptive |> take 500
+  |> iter (Printf.printf " %u%!")) |> print_newline