optimizations, formatting (sub 1s 2024)

Author: viandoxdev

2024/days/Day22.ml

@@ -29,39 +29,32 @@ module Sequence = struct
     map_quad (fun x -> (s / x mod 19) - 9) (19 * 19 * 19, 19 * 19, 19, 1)
 end
 
-let none = 10
-
-let change_table secret =
-  let m = Array.make (19 * 19 * 19 * 19) none in
-  let open Iter in
-  iterate step secret |> take 2001
-  |> map (fun x -> x mod 10)
-  |> fold_map
-       (fun (p, s) v ->
-         let ns = Sequence.rot s (v - p) in
-         ((v, ns), (ns, v)))
-       (0, 0)
-  |> drop 4
-  |> iter (fun (s, v) -> if m.(s) == none then m.(s) <- v);
-
-  m
-
-let profit seq table =
-  let r = table.(seq) in
-  if r = none then 0 else r
-
-let total_profit changes seq =
-  let open Iter in
-  of_list changes |> map (profit seq) |> sum
-
-let part1 secrets =
-  let open Iter in
-  of_list secrets |> map (Utils.repeat step 2000) |> sum
-
-let part2 secrets =
-  let open Iter in
-  let changes = on_list (map change_table) secrets in
-  Sequence.all_sequences |> map (total_profit changes) |> max_exn
+let profit_table secrets =
+  let n = 19 * 19 * 19 * 19 in
+  let profit = Array.make n 0 in
+  let seen = Array.make n 0 in
+
+  List.iteri
+    (fun i secret ->
+      let open Iter in
+      iterate step secret |> take 2001
+      |> map (fun x -> x mod 10)
+      |> fold_map
+           (fun (p, s) v ->
+             let ns = Sequence.rot s (v - p) in
+             ((v, ns), (ns, v)))
+           (0, 0)
+      |> drop 4
+      |> iter (fun (seq, v) ->
+             if seen.(seq) != i then (
+               profit.(seq) <- profit.(seq) + v;
+               seen.(seq) <- i)))
+    secrets;
+
+  profit
+
+let part1 secrets = Iter.(of_list secrets |> map (Utils.repeat step 2000) |> sum)
+let part2 = Array.fold_left max 0 % profit_table
 
 let day22 input =
   let secrets = parse input in

2024/days/Day25.ml

@@ -2,23 +2,27 @@ open Utils
 
 let parse input =
   String.split_on_char '\n' (input ^ "\n")
-    |> List.fold_left (fun (xs, b) l -> (
-      if l = "" && Option.is_some b then
-        (Option.get b :: xs, None)
-      else 
-        let b = Option.value ~default:0 b in
-        let b = String.fold_left (fun b c -> Int.(logor (shift_left b 1) (int_of_bool (c = '#')))) b l in
-        (xs, Some b)
-    )) ([], None)
-    |> fst
-    |> List.partition (fun b -> Int.logand b 1 = 0)
+  |> List.fold_left
+       (fun (xs, b) l ->
+         if l = "" && Option.is_some b then (Option.get b :: xs, None)
+         else
+           let b = Option.value ~default:0 b in
+           let b =
+             String.fold_left
+               (fun b c -> Int.(logor (shift_left b 1) (int_of_bool (c = '#'))))
+               b l
+           in
+           (xs, Some b))
+       ([], None)
+  |> fst
+  |> List.partition (fun b -> Int.logand b 1 = 0)
 
 let part1 locks keys =
   let open Iter in
   product (of_list locks) (of_list keys)
-    |> filter (fun (l, k) -> Int.logand l k = 0)
-    |> length
+  |> filter (fun (l, k) -> Int.logand l k = 0)
+  |> length
 
 let day25 input =
-  let (locks, keys) = parse input in
+  let locks, keys = parse input in
   (string_of_int @@ part1 locks keys, "")

2024/lib/Aoc.ml

@@ -118,8 +118,7 @@ let display_results res total_duration =
     (fun day ->
       print_endline @@ "[Day " ^ string_of_int day.number ^ "]";
       print_endline @@ "  Part1: " ^ day.part1;
-      if day.part2 <> "" then
-        print_endline @@ "  Part2: " ^ day.part2)
+      if day.part2 <> "" then print_endline @@ "  Part2: " ^ day.part2)
     res;
 
   print_endline "";