didn't know you could just use = to check equality of 2 nested lists..

day11.ml

@@ -74,19 +74,10 @@ let change_seats is_far l =
     )
   ) l
 
-let hash = Hashtbl.create 1000
-
-let grid_equal g1 g2 = (* abusing hash but not a drug problem *)
-  match Hashtbl.find_opt hash g2 with
-    | Some _ -> true
-    | None ->
-        let _ = Hashtbl.add hash g2 0 in
-        false
-
 let rec start is_far grid = (* keep changing seats until the grid stops changing *)
   (* print_grid grid; *)
   let grid' = change_seats is_far grid in
-  if grid_equal grid grid'
+  if grid = grid'
   then grid'
   else start is_far grid'