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#ifndef ubi_SplayTree_H
#define ubi_SplayTree_H
/* ========================================================================== **
* ubi_SplayTree.h
*
* Copyright (C) 1993,1995 by Christopher R. Hertel
*
* Email: crh@ubiqx.mn.org
* -------------------------------------------------------------------------- **
*
* This module implements "splay" trees. Splay trees are binary trees
* that are rearranged (splayed) whenever a node is accessed. The
* splaying process *tends* to make the tree bushier (improves balance),
* and the nodes that are accessed most frequently *tend* to be closer to
* the top.
*
* References: "Self-Adjusting Binary Search Trees", by Daniel Sleator and
* Robert Tarjan. Journal of the Association for Computing
* Machinery Vol 32, No. 3, July 1985 pp. 652-686
*
* -------------------------------------------------------------------------- **
*
* 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_SplayTree.h,v
* Revision 3.0 1997/12/08 05:32:35 crh
* This is a new major revision level because of a redesign of the handling
* of the pointers in the ubi_trNode structure. See ubi_BinTree for more
* info.
*
* Revision 2; 1995/02/27 - 1997/12/07:
* Major changes: added the function ubi_sptSplay().
*
* Revision 1; 93/10/15 - 95/02/27:
* Added the ubi_tr defines. See ubi_BinTree.h for more info.
*
* Revision 0.0 93/04/21 23:07:13 CRH
* Initial version, written by Christopher R. Hertel.
* This module implements Splay Trees using the ubi_BinTree module as a basis.
*
* ========================================================================== **
*/
#include "ubi_BinTree.h" /* Base binary tree functions, types, etc. */
/* ========================================================================== **
* Function prototypes...
*/
ubi_trBool ubi_sptInsert( ubi_btRootPtr RootPtr,
ubi_btNodePtr NewNode,
ubi_btItemPtr ItemPtr,
ubi_btNodePtr *OldNode );
/* ------------------------------------------------------------------------ **
* This function uses a non-recursive algorithm to add a new element to the
* splay tree.
*
* Input: RootPtr - a pointer to the ubi_btRoot structure that indicates
* the root of the tree to which NewNode is to be added.
* NewNode - a pointer to an ubi_btNode structure that is NOT
* part of any tree.
* ItemPtr - A pointer to the sort key that is stored within
* *NewNode. ItemPtr MUST point to information stored
* in *NewNode or an EXACT DUPLICATE. The key data
* indicated by ItemPtr is used to place the new node
* into the tree.
* OldNode - a pointer to an ubi_btNodePtr. When searching
* the tree, a duplicate node may be found. If
* duplicates are allowed, then the new node will
* be simply placed into the tree. If duplicates
* are not allowed, however, then one of two things
* may happen.
* 1) if overwritting *is not* allowed, this
* function will return FALSE (indicating that
* the new node could not be inserted), and
* *OldNode will point to the duplicate that is
* still in the tree.
* 2) if overwritting *is* allowed, then this
* function will swap **OldNode for *NewNode.
* In this case, *OldNode will point to the node
* that was removed (thus allowing you to free
* the node).
* ** If you are using overwrite mode, ALWAYS **
* ** check the return value of this parameter! **
* Note: You may pass NULL in this parameter, the
* function knows how to cope. If you do this,
* however, there will be no way to return a
* pointer to an old (ie. replaced) node (which is
* a problem if you are using overwrite mode).
*
* Output: a boolean value indicating success or failure. The function
* will return FALSE if the node could not be added to the tree.
* Such failure will only occur if duplicates are not allowed,
* nodes cannot be overwritten, AND a duplicate key was found
* within the tree.
* ------------------------------------------------------------------------ **
*/
ubi_btNodePtr ubi_sptRemove( ubi_btRootPtr RootPtr, ubi_btNodePtr DeadNode );
/* ------------------------------------------------------------------------ **
* This function removes the indicated node from the tree.
*
* Input: RootPtr - A pointer to the header of the tree that contains
* the node to be removed.
* DeadNode - A pointer to the node that will be removed.
*
* Output: This function returns a pointer to the node that was removed
* from the tree (ie. the same as DeadNode).
*
* Note: The node MUST be in the tree indicated by RootPtr. If not,
* strange and evil things will happen to your trees.
* ------------------------------------------------------------------------ **
*/
ubi_btNodePtr ubi_sptLocate( ubi_btRootPtr RootPtr,
ubi_btItemPtr FindMe,
ubi_trCompOps CompOp );
/* ------------------------------------------------------------------------ **
* The purpose of ubi_btLocate() is to find a node or set of nodes given
* a target value and a "comparison operator". The Locate() function is
* more flexible and (in the case of trees that may contain dupicate keys)
* more precise than the ubi_btFind() function. The latter is faster,
* but it only searches for exact matches and, if the tree contains
* duplicates, Find() may return a pointer to any one of the duplicate-
* keyed records.
*
* Input:
* RootPtr - A pointer to the header of the tree to be searched.
* FindMe - An ubi_btItemPtr that indicates the key for which to
* search.
* CompOp - One of the following:
* CompOp Return a pointer to the node with
* ------ ---------------------------------
* ubi_trLT - the last key value that is less
* than FindMe.
* ubi_trLE - the first key matching FindMe, or
* the last key that is less than
* FindMe.
* ubi_trEQ - the first key matching FindMe.
* ubi_trGE - the first key matching FindMe, or the
* first key greater than FindMe.
* ubi_trGT - the first key greater than FindMe.
* Output:
* A pointer to the node matching the criteria listed above under
* CompOp, or NULL if no node matched the criteria.
*
* Notes:
* In the case of trees with duplicate keys, Locate() will behave as
* follows:
*
* Find: 3 Find: 3
* Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6
* ^ ^ ^ ^ ^
* LT EQ GT LE GE
*
* That is, when returning a pointer to a node with a key that is LESS
* THAN the target key (FindMe), Locate() will return a pointer to the
* LAST matching node.
* When returning a pointer to a node with a key that is GREATER
* THAN the target key (FindMe), Locate() will return a pointer to the
* FIRST matching node.
*
* See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf().
* ------------------------------------------------------------------------ **
*/
ubi_btNodePtr ubi_sptFind( ubi_btRootPtr RootPtr,
ubi_btItemPtr FindMe );
/* ------------------------------------------------------------------------ **
* This function performs a non-recursive search of a tree for any node
* matching a specific key.
*
* Input:
* RootPtr - a pointer to the header of the tree to be searched.
* FindMe - a pointer to the key value for which to search.
*
* Output:
* A pointer to a node with a key that matches the key indicated by
* FindMe, or NULL if no such node was found.
*
* Note: In a tree that allows duplicates, the pointer returned *might
* not* point to the (sequentially) first occurance of the
* desired key. In such a tree, it may be more useful to use
* ubi_sptLocate().
* ------------------------------------------------------------------------ **
*/
void ubi_sptSplay( ubi_btRootPtr RootPtr,
ubi_btNodePtr SplayMe );
/* ------------------------------------------------------------------------ **
* This function allows you to splay the tree at a given node, thus moving
* the node to the top of the tree.
*
* Input:
* RootPtr - a pointer to the header of the tree to be splayed.
* SplayMe - a pointer to a node within the tree. This will become
* the new root node.
* Output: None.
*
* Notes: This is an uncharacteristic function for this group of modules
* in that it provides access to the internal balancing routines,
* which would normally be hidden.
* Splaying the tree will not damage it (assuming that I've done
* *my* job), but there is overhead involved. I don't recommend
* that you use this function unless you understand the underlying
* Splay Tree.
* ------------------------------------------------------------------------ **
*/
int ubi_sptModuleID( int size, char *list[] );
/* ------------------------------------------------------------------------ **
* Returns a set of strings that identify the module.
*
* Input: size - The number of elements in the array <list>.
* list - An array of pointers of type (char *). This array
* should, initially, be empty. This function will fill
* in the array with pointers to strings.
* Output: The number of elements of <list> that were used. If this value
* is less than <size>, the values of the remaining elements are
* not guaranteed.
*
* Notes: Please keep in mind that the pointers returned indicate strings
* stored in static memory. Don't free() them, don't write over
* them, etc. Just read them.
* ------------------------------------------------------------------------ **
*/
/* -------------------------------------------------------------------------- **
* Masquarade...
*
* This set of defines allows you to write programs that will use any of the
* implemented binary tree modules (currently BinTree, AVLtree, and SplayTree).
* Instead of using ubi_bt..., use ubi_tr..., and select the tree type by
* including the appropriate module header.
*/
#undef ubi_trInsert
#undef ubi_trRemove
#undef ubi_trLocate
#undef ubi_trFind
#undef ubi_trModuleID
#define ubi_trInsert( Rp, Nn, Ip, On ) \
ubi_sptInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \
(ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) )
#define ubi_trRemove( Rp, Dn ) \
ubi_sptRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) )
#define ubi_trLocate( Rp, Ip, Op ) \
ubi_sptLocate( (ubi_btRootPtr)(Rp), \
(ubi_btItemPtr)(Ip), \
(ubi_trCompOps)(Op) )
#define ubi_trFind( Rp, Ip ) \
ubi_sptFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) )
#define ubi_trModuleID( s, l ) ubi_sptModuleID( s, l )
/* ================================ The End ================================= */
#endif /* ubi_SplayTree_H */
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