From 791157b3035d856518044ab56dfe44071c2e63ea Mon Sep 17 00:00:00 2001
From: Acvaxoort <rutiousag@gmail.com>
Date: Thu, 19 Dec 2024 23:19:35 +0100
Subject: [PATCH] day19 shorter

---
 19/main.ml | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/19/main.ml b/19/main.ml
index 9d8c8f1..ff34c30 100644
--- a/19/main.ml
+++ b/19/main.ml
@@ -12,32 +12,26 @@ let get_input_lists list_of_lines =
   match list_of_lines with
   | towels_list :: _ :: tail -> (towels_list, tail)
   | _ -> raise (Invalid_argument "Not enough lines")  
-  
-let rec try_any_towel cache towels pattern =
-  towels
-    |> List.filter (fun towel -> 
-      String.starts_with ~prefix:towel pattern)
-    |> List.map (fun towel -> 
-      try_construct cache towels (String.sub pattern (String.length towel) (String.length pattern - String.length towel)))
-    |> List.fold_left Int.add 0
 
-and try_construct cache towels pattern =
-  if String.length pattern = 0 then
-    1
-  else
-    match Hashtbl.find_opt cache pattern with
-    | Some result ->
-      result
-    | None ->
-      let result = try_any_towel cache towels pattern in
-      Hashtbl.add cache pattern result;
-      result
+let rec try_construct cache towels pattern =
+  match Hashtbl.find_opt cache pattern with
+  | Some result -> result
+  | None ->
+    let result = towels
+      |> List.filter (fun towel -> 
+        String.starts_with ~prefix:towel pattern)
+      |> List.map (fun towel -> 
+        try_construct cache towels (String.sub pattern (String.length towel) (String.length pattern - String.length towel)))
+      |> List.fold_left Int.add 0 in
+    Hashtbl.add cache pattern result;
+    result
 
 let () =
   let f = open_in "input.txt" in
   let towels_str, patterns_list = list_of_lines f |> get_input_lists in
   let towels_list = towels_str |> String.split_on_char ',' |> List.map (fun x -> x |> String.trim) in
   let cache = Hashtbl.create 1024 in
+  Hashtbl.add cache "" 1;
   let possibilities_list = patterns_list |> List.map (try_construct cache towels_list) in
   let result = possibilities_list |> List.filter (fun x-> x > 0) |> List.length  in
   let result2 = List.fold_left Int.add 0 possibilities_list in