From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,bb89030c68b82ceb,start
X-Google-Attributes: gid103376,public
From: Gerald Ang <tmang@student.ecu.edu.au>
Subject: help for my project
Date: 2000/05/09
Message-ID: <3917F194.F6C1BB73@student.ecu.edu.au>#1/1
X-Deja-AN: 621067637
Content-Transfer-Encoding: 7bit
X-Accept-Language: en
Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854";
 x-mac-creator="4D4F5353"
Organization: Edith Cowan University
Mime-Version: 1.0
Reply-To: tmang@student.ecu.edu.au
Newsgroups: comp.lang.ada
Date: 2000-05-09T00:00:00+00:00
List-Id: <comp.lang.ada>

Help is needed for my assignment. Below is a copy of the specificaton
code, please help with the Procedure Add.

with Ada.Text_IO;

with Unchecked_Deallocation;

generic

type Symbol is (<>);

package Symbolized_Search_Tree is

type Tree is private;

type Symbol_Array is array(Integer range <>) of Symbol;

type Sequence is access Symbol_Array;

type Sequence_Array is array(Integer range <>) of Sequence;

package Symbol_IO is new Ada.Text_IO.Enumeration_IO(Enum => Symbol);

procedure Add(A_Tree: in out Tree;
                            Symbols: in Symbol_Array;
                            Result: out Integer);

  -- adds Symbols' non-shared elements to A_Tree and sets marker
  --
  -- if no Symbols
  -- then
  --   Result:= -1
  --   return
  -- end if
  --
 -- if no A_Tree nodes
  -- then
  --   create root node, non-leaf nodes, leaf node
  --   assign Symbols' elements to root node, non-leaf nodes
  --   assign True to leaf node marker
  --   Result:= number of nodes created
  --   return
  -- end if
  --
  -- determine number of Symbols' elements contained in A_Tree
  --
  -- if A_Tree contains all Symbols' elements and True marker
  -- then
  --   Result:= -2
  --   return
  -- end if
  --
  -- if A_Tree contains all Symbols' elements and False marker
  -- then
  --   assign True to marker
  --   Result:= 0
  --   return
  -- end if
  --
  -- if A_Tree contains some of Symbols' elements
  -- then
  --   augment differing non-root node
  --   create non-leaf nodes, leaf nodes
  --   assign Symbols' tail elements to non-root node, non-leaf nodes
  --   assign True to leaf node marker
  --   Result:= number of nodes augmented/created
  --   return
  -- end if
  --
  -- if A_Tree contains none of Symbols' elements
  -- then
  --   augment root node
  --   create non-leaf nodes, leaf node
  --   assign Symbols' elements to root node, non-leaf nodes
  --   assign True to leaf node marker
  --   Result:= number of nodes augmented/created
  --   return
  -- end if


private

  type Node(Length: Integer);

  type Tree is access Node;

  type Tree_Array is array (Integer range <>) of Tree;

  type Node(Length: Integer) is
    record
      Marker: Boolean;
      Symbols: Symbol_Array(1..Length);
      Subtrees: Tree_Array(1..Length);
    end record;
  -- a leaf node has Length = 0 and Marker = True
  -- a partial-leaf node has Length > 0 and Marker = True
  -- a non-leaf node has Length > 0 and Marker = False
  -- for 1 <= I <= Length-1, Node.Symbols(I) < Node.Symbols(I+1)

  Null_Tree: constant Tree:= null;

  procedure Deallocate is

    new Unchecked_Deallocation(Object=>Node,
                                                    Name=>Tree);

end Symbolized_Search_Tree;