104 lines
2.9 KiB
OCaml
104 lines
2.9 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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type ('a, 'b) t =
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Empty
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| Node of ('a, 'b) t * 'a * 'b * ('a, 'b) t * int
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let empty = Empty
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let height = function
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Empty -> 0
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| Node(_,_,_,_,h) -> h
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let create l x d r =
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let hl = height l and hr = height r in
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Node(l, x, d, r, (if hl >= hr then hl + 1 else hr + 1))
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let bal l x d r =
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let hl = height l and hr = height r in
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if hl > hr + 1 then
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let (Node(ll, lv, ld, lr, _)) = l in
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if height ll >= height lr then
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create ll lv ld (create lr x d r)
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else
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let (Node(lrl, lrv, lrd, lrr, _)) = lr in
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create (create ll lv ld lrl) lrv lrd (create lrr x d r)
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else if hr > hl + 1 then
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let (Node(rl, rv, rd, rr, _)) = r in
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if height rr >= height rl then
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create (create l x d rl) rv rd rr
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else
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let (Node(rll, rlv, rld, rlr, _)) = rl in
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create (create l x d rll) rlv rld (create rlr rv rd rr)
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else
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create l x d r
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let rec add x data = function
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Empty ->
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Node(Empty, x, data, Empty, 1)
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| Node(l, v, d, r, h) as t ->
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let c = compare x v in
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if c = 0 then
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Node(l, x, data, r, h)
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else if c < 0 then
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bal (add x data l) v d r
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else
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bal l v d (add x data r)
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let rec find x = function
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Empty ->
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raise Not_found
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| Node(l, v, d, r, _) ->
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let c = compare x v in
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if c = 0 then d
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else find x (if c < 0 then l else r)
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let rec merge t1 t2 =
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match (t1, t2) with
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(Empty, t) -> t
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| (t, Empty) -> t
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| (Node(l1, v1, d1, r1, h1), Node(l2, v2, d2, r2, h2)) ->
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bal l1 v1 d1 (bal (merge r1 l2) v2 d2 r2)
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let rec remove x = function
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Empty ->
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Empty
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| Node(l, v, d, r, h) as t ->
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let c = compare x v in
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if c = 0 then
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merge l r
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else if c < 0 then
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bal (remove x l) v d r
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else
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bal l v d (remove x r)
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let rec iter f = function
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Empty -> ()
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| Node(l, v, d, r, _) ->
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iter f l; f v d; iter f r
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open Format
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let print print_key print_data tbl =
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open_hvbox 2;
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print_string "[[";
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iter (fun k d ->
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open_hovbox 2;
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print_key k; print_string " ->"; print_space();
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print_data d; print_string ";";
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close_box(); print_space())
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tbl;
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print_string "]]";
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close_box()
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