reactos/lib/rtl/splaytree.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2003 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id: splaytree.c,v 1.1 2004/06/20 23:27:21 gdalsnes Exp $
  20  *
  21  * COPYRIGHT:         See COPYING in the top level directory
  22  * PROJECT:           ReactOS system libraries
  23  * PURPOSE:           Splay-Tree implementation
  24  * FILE:              lib/rtl/splaytree.c
  25  */
  26
  27 #include <ddk/ntddk.h>
  28
  29 /* FUNCTIONS *****************************************************************/
  30
  31 PRTL_SPLAY_LINKS STDCALL
  32 RtlSubtreePredecessor (IN PRTL_SPLAY_LINKS Links)
  33 {
  34    PRTL_SPLAY_LINKS Child;
  35
  36    Child = Links->RightChild;
  37    if (Child == NULL)
  38       return NULL;
  39
  40    if (Child->LeftChild == NULL)
  41       return Child;
  42
  43    /* Get left-most child */
  44    while (Child->LeftChild != NULL)
  45       Child = Child->LeftChild;
  46
  47    return Child;
  48 }
  49
  50
  51 PRTL_SPLAY_LINKS STDCALL
  52 RtlSubtreeSuccessor (IN PRTL_SPLAY_LINKS Links)
  53 {
  54    PRTL_SPLAY_LINKS Child;
  55
  56    Child = Links->LeftChild;
  57    if (Child == NULL)
  58       return NULL;
  59
  60    if (Child->RightChild == NULL)
  61       return Child;
  62
  63    /* Get right-most child */
  64    while (Child->RightChild != NULL)
  65       Child = Child->RightChild;
  66
  67    return Child;
  68 }
  69
  70 /* EOF */