(*
* Heap: heaps implemented both functionally and imperatively
* Copyright (C) 2003 Jean-Christophe FILLIATRE
*
* This software is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License version 2, as published by the Free Software Foundation.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* See the GNU Library General Public License version 2 for more details
* (enclosed in the file LGPL).
*)
(* Heaps *)
module type Ordered = sig
type t
val compare : t -> t -> int
end
exception EmptyHeap
(*S Imperative implementation. *)
module Imperative(X: Ordered) : sig
(* Type of imperative heaps.
(In the following [n] refers to the number of elements in the heap) *)
type t
(* [create c] creates a new heap, with initial capacity of [c] *)
val create : int -> t
(* [is_empty h] checks the emptiness of [h] *)
val is_empty : t -> bool
(* [add x h] adds a new element [x] in heap [h]; size of [h] is doubled
when maximum capacity is reached; complexity $O(log(n))$ *)
val add : t -> X.t -> unit
(* [maximum h] returns the maximum element of [h]; raises [EmptyHeap]
when [h] is empty; complexity $O(1)$ *)
val maximum : t -> X.t
(* [remove h] removes the maximum element of [h]; raises [EmptyHeap]
when [h] is empty; complexity $O(log(n))$ *)
val remove : t -> unit
(* [pop_maximum h] removes the maximum element of [h] and returns it;
raises [EmptyHeap] when [h] is empty; complexity $O(log(n))$ *)
val pop_maximum : t -> X.t
(* usual iterators and combinators; elements are presented in
arbitrary order *)
val iter : (X.t -> unit) -> t -> unit
val fold : (X.t -> 'a -> 'a) -> t -> 'a -> 'a
end
(*S Functional implementation. *)
module type FunctionalSig = sig
(* heap elements *)
type elt
(* Type of functional heaps *)
type t
(* The empty heap *)
val empty : t
(* [add x h] returns a new heap containing the elements of [h], plus [x];
complexity $O(log(n))$ *)
val add : elt -> t -> t
(* [maximum h] returns the maximum element of [h]; raises [EmptyHeap]
when [h] is empty; complexity $O(1)$ *)
val maximum : t -> elt
(* [remove h] returns a new heap containing the elements of [h], except
the maximum of [h]; raises [EmptyHeap] when [h] is empty;
complexity $O(log(n))$ *)
val remove : t -> t
(* usual iterators and combinators; elements are presented in
arbitrary order *)
val iter : (elt -> unit) -> t -> unit
val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
end
module Functional(X: Ordered) : FunctionalSig with type elt = X.t