ubi_bintree.h

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#ifndef UBI_BINTREE_H
#define UBI_BINTREE_H
/* ========================================================================== **
 *                              ubi_BinTree.h
 *
 *  Copyright (C) 1991-1998 by Christopher R. Hertel
 *
 *  Email:  [e-mail]
 * -------------------------------------------------------------------------- **
 *
 *  This module implements a simple binary tree.
 *
 * -------------------------------------------------------------------------- **
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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 for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * -------------------------------------------------------------------------- **
 *
 * Log: ubi_BinTree.h,v
 * Revision 4.12  2004/06/06 04:51:56  crh
 * Fixed a small typo in ubi_BinTree.c (leftover testing cruft).
 * Did a small amount of formatting touchup to ubi_BinTree.h.
 *
 * Revision 4.11  2004/06/06 03:14:09  crh
 * Rewrote the ubi_btLeafNode() function.  It now takes several paths in an
 * effort to find a deeper leaf node.  There is a small amount of extra
 * overhead, but it is limited.
 *
 * Revision 4.10  2000/06/06 20:38:40  crh
 * In the ReplaceNode() function, the old node header was being copied
 * to the new node header using a byte-by-byte copy.  This was causing
 * the 'insure' software testing program to report a memory leak.  The
 * fix was to do a simple assignement: *newnode = *oldnode;
 * This quieted the (errant) memory leak reports and is probably a bit
 * faster than the bytewise copy.
 *
 * Revision 4.9  2000/01/08 23:24:30  crh
 * Clarified a variety of if( pointer ) lines, replacing them with
 * if( NULL != pointer ).  This is more correct, and I have heard
 * of at least one (obscure?) system out there that uses a non-zero
 * value for NULL.
 * Also, speed improvement in Neighbor().  It was comparing pointers
 * when it could have compared two gender values.  The pointer
 * comparison was somewhat indirect (does pointer equal the pointer
 * of the parent of the node pointed to by pointer).  Urq.
 *
 * Revision 4.8  1999/09/22 03:40:30  crh
 * Modified ubi_btTraverse() and ubi_btKillTree().  They now return an
 * unsigned long indicating the number of nodes processed.  The change
 * is subtle.  An empty tree formerly returned False, and now returns
 * zero.
 *
 * Revision 4.7  1998/10/21 06:15:07  crh
 * Fixed bugs in FirstOf() and LastOf() reported by Massimo Campostrini.
 * See function comments.
 *
 * Revision 4.6  1998/07/25 17:02:10  crh
 * Added the ubi_trNewTree() macro.
 *
 * Revision 4.5  1998/06/04 21:29:27  crh
 * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files.
 * This is more "standard", and is what people expect.  Weird, eh?
 *
 * Revision 4.4  1998/06/03 17:42:46  crh
 * Further fiddling with sys_include.h.  It's now in ubi_BinTree.h which is
 * included by all of the binary tree files.
 *
 * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in
 *           ubi_AVLtree.h and ubi_SplayTree.h.  This allows easy swapping
 *           of tree types by simply changing a header.  Unfortunately, the
 *           macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will
 *           conflict if used together.  You must either choose a single tree
 *           type, or use the underlying function calls directly.  Compare
 *           the two header files for more information.
 *
 * Revision 4.3  1998/06/02 01:28:43  crh
 * Changed ubi_null.h to sys_include.h to make it more generic.
 *
 * Revision 4.2  1998/05/20 04:32:36  crh
 * The C file now includes ubi_null.h.  See ubi_null.h for more info.
 * Also, the balance and gender fields of the node were declared as
 * signed char.  As I understand it, at least one SunOS or Solaris
 * compiler doesn't like "signed char".  The declarations were
 * wrong anyway, so I changed them to simple "char".
 *
 * Revision 4.1  1998/03/31 06:13:47  crh
 * Thomas Aglassinger sent E'mail pointing out errors in the
 * dereferencing of function pointers, and a missing typecast.
 * Thanks, Thomas!
 *
 * Revision 4.0  1998/03/10 03:16:04  crh
 * Added the AVL field 'balance' to the ubi_btNode structure.  This means
 * that all BinTree modules now use the same basic node structure, which
 * greatly simplifies the AVL module.
 * Decided that this was a big enough change to justify a new major revision
 * number.  3.0 was an error, so we're at 4.0.
 *
 * Revision 2.6  1998/01/24 06:27:30  crh
 * Added ubi_trCount() macro.
 *
 * Revision 2.5  1997/12/23 03:59:21  crh
 * In this version, all constants & macros defined in the header file have
 * the ubi_tr prefix.  Also cleaned up anything that gcc complained about
 * when run with '-pedantic -fsyntax-only -Wall'.
 *
 * Revision 2.4  1997/07/26 04:11:14  crh
 * + Just to be annoying I changed ubi_TRUE and ubi_FALSE to ubi_trTRUE
 *   and ubi_trFALSE.
 * + There is now a type ubi_trBool to go with ubi_trTRUE and ubi_trFALSE.
 * + There used to be something called "ubi_TypeDefs.h".  I got rid of it.
 * + Added function ubi_btLeafNode().
 *
 * Revision 2.3  1997/06/03 05:15:27  crh
 * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid conflicts.
 * Also changed the interface to function InitTree().  See the comments
 * for this function for more information.
 *
 * Revision 2.2  1995/10/03 22:00:40  CRH
 * Ubisized!
 * 
 * Revision 2.1  95/03/09  23:43:46  CRH
 * Added the ModuleID static string and function.  These modules are now
 * self-identifying.
 * 
 * Revision 2.0  95/02/27  22:00:33  CRH
 * Revision 2.0 of this program includes the following changes:
 *
 *     1)  A fix to a major typo in the RepaceNode() function.
 *     2)  The addition of the static function Border().
 *     3)  The addition of the public functions FirstOf() and LastOf(), which
 *         use Border(). These functions are used with trees that allow
 *         duplicate keys.
 *     4)  A complete rewrite of the Locate() function.  Locate() now accepts
 *         a "comparison" operator.
 *     5)  Overall enhancements to both code and comments.
 *
 * I decided to give this a new major rev number because the interface has
 * changed.  In particular, there are two new functions, and changes to the
 * Locate() function.
 *
 * Revision 1.0  93/10/15  22:55:04  CRH
 * With this revision, I have added a set of #define's that provide a single,
 * standard API to all existing tree modules.  Until now, each of the three
 * existing modules had a different function and typedef prefix, as follows:
 *
 *       Module        Prefix
 *     ubi_BinTree     ubi_bt
 *     ubi_AVLtree     ubi_avl
 *     ubi_SplayTree   ubi_spt
 *
 * To further complicate matters, only those portions of the base module
 * (ubi_BinTree) that were superceeded in the new module had the new names.
 * For example, if you were using ubi_SplayTree, the locate function was
 * called "ubi_sptLocate", but the next and previous functions remained
 * "ubi_btNext" and "ubi_btPrev".
 *
 * This was not too terrible if you were familiar with the modules and knew
 * exactly which tree model you wanted to use.  If you wanted to be able to
 * change modules (for speed comparisons, etc), things could get messy very
 * quickly.
 *
 * So, I have added a set of defined names that get redefined in any of the
 * descendant modules.  To use this standardized interface in your code,
 * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with
 * "ubi_tr".  The "ubi_tr" names will resolve to the correct function or
 * datatype names for the module that you are using.  Just remember to
 * include the header for that module in your program file.  Because these
 * names are handled by the preprocessor, there is no added run-time
 * overhead.
 *
 * Note that the original names do still exist, and can be used if you wish
 * to write code directly to a specific module.  This should probably only be
 * done if you are planning to implement a new descendant type, such as
 * red/black trees.  CRH
 *
 *  V0.0 - June, 1991   -  Written by Christopher R. Hertel (CRH).
 *
 * ========================================================================== **
 */

#include "sys_include.h"  /* Global include file, used to adapt the ubiqx
                           * modules to the host environment and the project
                           * with which the modules will be used.  See
                           * sys_include.h for more info.
                           */

/* -------------------------------------------------------------------------- **
 * Macros and constants.
 *
 *  General purpose:
 *    ubi_trTRUE  - Boolean TRUE.
 *    ubi_trFALSE - Boolean FALSE.
 *
 *  Flags used in the tree header:
 *    ubi_trOVERWRITE   - This flag indicates that an existing node may be
 *                        overwritten by a new node with a matching key.
 *    ubi_trDUPKEY      - This flag indicates that the tree allows duplicate
 *                        keys.  If the tree does allow duplicates, the
 *                        overwrite flag is ignored.
 *
 *  Node link array index constants:  (Each node has an array of three
 *  pointers.  One to the left, one to the right, and one back to the
 *  parent.)
 *    ubi_trLEFT    - Left child pointer.
 *    ubi_trPARENT  - Parent pointer.
 *    ubi_trRIGHT   - Right child pointer.
 *    ubi_trEQUAL   - Synonym for PARENT.
 *
 *  ubi_trCompOps:  These values are used in the ubi_trLocate() function.
 *    ubi_trLT  - request the first instance of the greatest key less than
 *                the search key.
 *    ubi_trLE  - request the first instance of the greatest key that is less
 *                than or equal to the search key.
 *    ubi_trEQ  - request the first instance of key that is equal to the
 *                search key.
 *    ubi_trGE  - request the first instance of a key that is greater than
 *                or equal to the search key.
 *    ubi_trGT  - request the first instance of the first key that is greater
 *                than the search key.
 * -------------------------------------------------------------------------- **
 */

#define ubi_trTRUE  0xFF
#define ubi_trFALSE 0x00

#define ubi_trOVERWRITE 0x01        /* Turn on allow overwrite      */
#define ubi_trDUPKEY    0x02        /* Turn on allow duplicate keys */

/* Pointer array index constants... */
#define ubi_trLEFT   0x00
#define ubi_trPARENT 0x01
#define ubi_trRIGHT  0x02
#define ubi_trEQUAL  ubi_trPARENT

typedef enum {
  ubi_trLT = 1,
  ubi_trLE,
  ubi_trEQ,
  ubi_trGE,
  ubi_trGT
  } ubi_trCompOps;

/* -------------------------------------------------------------------------- **
 * These three macros allow simple manipulation of pointer index values (LEFT,
 * RIGHT, and PARENT).
 *
 *    Normalize() -  converts {LEFT, PARENT, RIGHT} into {-1, 0 ,1}.  C
 *                   uses {negative, zero, positive} values to indicate
 *                   {less than, equal to, greater than}.
 *    AbNormal()  -  converts {negative, zero, positive} to {LEFT, PARENT,
 *                   RIGHT} (opposite of Normalize()).  Note: C comparison
 *                   functions, such as strcmp(), return {negative, zero,
 *                   positive} values, which are not necessarily {-1, 0,
 *                   1}.  This macro uses the the ubi_btSgn() function to
 *                   compensate.
 *    RevWay()    -  converts LEFT to RIGHT and RIGHT to LEFT.  PARENT (EQUAL)
 *                   is left as is.
 * -------------------------------------------------------------------------- **
 */

#define ubi_trNormalize(W) ((char)( (W) - ubi_trEQUAL ))
#define ubi_trAbNormal(W)  ((char)( ((char)ubi_btSgn( (long)(W) )) \
                                         + ubi_trEQUAL ))
#define ubi_trRevWay(W)    ((char)( ubi_trEQUAL - ((W) - ubi_trEQUAL) ))

/* -------------------------------------------------------------------------- **
 * These macros allow us to quickly read the values of the OVERWRITE and
 * DUPlicate KEY bits of the tree root flags field.
 * -------------------------------------------------------------------------- **
 */

#define ubi_trDups_OK(A) \
        ((ubi_trDUPKEY & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE))
#define ubi_trOvwt_OK(A) \
        ((ubi_trOVERWRITE & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE))

/* -------------------------------------------------------------------------- **
 * Additional Macros...
 *
 *  ubi_trCount()   - Given a pointer to a tree root, this macro returns the
 *                    number of nodes currently in the tree.
 *
 *  ubi_trNewTree() - This macro makes it easy to declare and initialize a
 *                    tree header in one step.  The line