val ints_of_string : ?sep:string -> string -> int list
(** [nums_from_string ?sep s] takes a string of integers separated by [sep] and
    gives back a list of the integers. By default [sep] is " " *)

val distance1 : int -> int -> int
(** [distance1 a b] returns the absolute difference between [a] and [b]. *)

val strings_of_file : string -> string list
(** [strings_from_file fname] returns a list of strings from the file [fname].
    Each string represents a line from the file. *)

val main : (string -> 'a) -> (('b -> string) * ('a -> 'b)) list -> unit
(** [main prep parts] executes an advent of code problem. [prep fname] should be
    a function that returns the input from [fname]. Each elemet of [parts] is a
    pair of functions. The first converts the output to a string (for example
    [string_of_int]). The second executes the given part. Output is given as if
    done by: [print_string ( prep fname |> snd |> fst )] *)

(** Module representing a pair of integers, useful for Set.Make *)
module IntPair : sig
  type t = int * int
  (** [t] is a pair of integers *)

  val compare : t -> t -> int
  (** Standard comparion operation. *)
end

(** IntPairSet represents a Set of integers, see standard docs for info. *)
module IntPairSet : sig
  type elt = IntPair.t
  type t = Set.Make(IntPair).t

  val empty : t
  val add : elt -> t -> t
  val singleton : elt -> t
  val remove : elt -> t -> t
  val union : t -> t -> t
  val inter : t -> t -> t
  val disjoint : t -> t -> bool
  val diff : t -> t -> t
  val cardinal : t -> int
  val elements : t -> elt list
  val min_elt : t -> elt
  val min_elt_opt : t -> elt option
  val max_elt : t -> elt
  val max_elt_opt : t -> elt option
  val choose : t -> elt
  val choose_opt : t -> elt option
  val find : elt -> t -> elt
  val find_opt : elt -> t -> elt option
  val find_first : (elt -> bool) -> t -> elt
  val find_first_opt : (elt -> bool) -> t -> elt option
  val find_last : (elt -> bool) -> t -> elt
  val find_last_opt : (elt -> bool) -> t -> elt option
  val iter : (elt -> unit) -> t -> unit
  val fold : (elt -> 'acc -> 'acc) -> t -> 'acc -> 'acc
  val map : (elt -> elt) -> t -> t
  val filter : (elt -> bool) -> t -> t
  val filter_map : (elt -> elt option) -> t -> t
  val partition : (elt -> bool) -> t -> t * t
  val split : elt -> t -> t * bool * t
  val is_empty : t -> bool
  val mem : elt -> t -> bool
  val equal : t -> t -> bool
  val compare : t -> t -> int
  val subset : t -> t -> bool
  val for_all : (elt -> bool) -> t -> bool
  val exists : (elt -> bool) -> t -> bool
  val to_list : t -> elt list
  val of_list : elt list -> t
  val to_seq_from : elt -> t -> elt Seq.t
  val to_seq : t -> elt Seq.t
  val to_rev_seq : t -> elt Seq.t
  val add_seq : elt Seq.t -> t -> t
  val of_seq : elt Seq.t -> t
end