#ifndef UBI_BINTREE_H #define UBI_BINTREE_H /* ========================================================================== ** * ubi_BinTree.h * * Copyright (C) 1991-1998 by Christopher R. Hertel * * Email: crh@ubiqx.mn.org * -------------------------------------------------------------------------- ** * * 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 * * static ubi_trNewTree( MyTree, cmpfn, ubi_trDUPKEY ); * * is equivalent to * * static ubi_trRoot MyTree[1] * = {{ NULL, cmpfn, 0, ubi_trDUPKEY }}; * * -------------------------------------------------------------------------- ** */ #define ubi_trCount( R ) (((ubi_trRootPtr)(R))->count) #define ubi_trNewTree( N, C, F ) ubi_trRoot (N)[1] = {{ NULL, (C), 0, (F) }} /* -------------------------------------------------------------------------- ** * Typedefs... * * ubi_trBool - Your typcial true or false... * * Item Pointer: The ubi_btItemPtr is a generic pointer. It is used to * indicate a key that is being searched for within the tree. * Searching occurs whenever the ubi_trFind(), ubi_trLocate(), * or ubi_trInsert() functions are called. * -------------------------------------------------------------------------- ** */ typedef unsigned char ubi_trBool; typedef void *ubi_btItemPtr; /* A pointer to key data within a node. */ /* ------------------------------------------------------------------------- ** * Binary Tree Node Structure: This structure defines the basic elements of * the tree nodes. In general you *SHOULD NOT PLAY WITH THESE FIELDS*! * But, of course, I have to put the structure into this header so that * you can use it as a building block. * * The fields are as follows: * Link - an array of pointers. These pointers are manipulated by * the BT routines. The pointers indicate the left and right * child nodes and the parent node. By keeping track of the * parent pointer, we avoid the need for recursive routines or * hand-tooled stacks to keep track of our path back to the * root. The use of these pointers is subject to change without * notice. * gender - a one-byte field indicating whether the node is the RIGHT or * LEFT child of its parent. If the node is the root of the * tree, gender will be PARENT. * balance - only used by the AVL tree module. This field indicates * the height balance at a given node. See ubi_AVLtree for * details. * * ------------------------------------------------------------------------- ** */ typedef struct ubi_btNodeStruct { struct ubi_btNodeStruct *Link[ 3 ]; char gender; char balance; } ubi_btNode; typedef ubi_btNode *ubi_btNodePtr; /* Pointer to an ubi_btNode structure. */ /* ------------------------------------------------------------------------- ** * The next three typedefs define standard function types used by the binary * tree management routines. In particular: * * ubi_btCompFunc is a pointer to a comparison function. Comparison * functions are passed an ubi_btItemPtr and an * ubi_btNodePtr. They return a value that is (<0), 0, * or (>0) to indicate that the Item is (respectively) * "less than", "equal to", or "greater than" the Item * contained within the node. (See ubi_btInitTree()). * ubi_btActionRtn is a pointer to a function that may be called for each * node visited when performing a tree traversal (see * ubi_btTraverse()). The function will be passed two * parameters: the first is a pointer to a node in the * tree, the second is a generic pointer that may point to * anything that you like. * ubi_btKillNodeRtn is a pointer to a function that will deallocate the * memory used by a node (see ubi_btKillTree()). Since * memory management is left up to you, deallocation may * mean anything that you want it to mean. Just remember * that the tree *will* be destroyed and that none of the * node pointers will be valid any more. * ------------------------------------------------------------------------- ** */ typedef int (*ubi_btCompFunc)( ubi_btItemPtr, ubi_btNodePtr ); typedef void (*ubi_btActionRtn)( ubi_btNodePtr, void * ); typedef void (*ubi_btKillNodeRtn)( ubi_btNodePtr ); /* -------------------------------------------------------------------------- ** * Tree Root Structure: This structure gives us a convenient handle for * accessing whole binary trees. The fields are: * root - A pointer to the root node of the tree. * count - A count of the number of nodes stored in the tree. * cmp - A pointer to the comparison routine to be used when building or * searching the tree. * flags - A set of bit flags. Two flags are currently defined: * * ubi_trOVERWRITE - If set, this flag indicates that a new node should * (bit 0x01) overwrite an old node if the two have identical * keys (ie., the keys are equal). * ubi_trDUPKEY - If set, this flag indicates that the tree is * (bit 0x02) allowed to contain nodes with duplicate keys. * * NOTE: ubi_trInsert() tests ubi_trDUPKEY before ubi_trOVERWRITE. * * All of these values are set when you initialize the root structure by * calling ubi_trInitTree(). * -------------------------------------------------------------------------- ** */ typedef struct { ubi_btNodePtr root; /* A pointer to the root node of the tree */ ubi_btCompFunc cmp; /* A pointer to the tree's comparison function */ unsigned long count; /* A count of the number of nodes in the tree */ char flags; /* Overwrite Y|N, Duplicate keys Y|N... */ } ubi_btRoot; typedef ubi_btRoot *ubi_btRootPtr; /* Pointer to an ubi_btRoot structure. */ /* -------------------------------------------------------------------------- ** * Function Prototypes. */ long ubi_btSgn( long x ); /* ------------------------------------------------------------------------ ** * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}. * * Input: x - a signed long integer value. * * Output: the "sign" of x, represented as follows: * -1 == negative * 0 == zero (no sign) * 1 == positive * * Note: This utility is provided in order to facilitate the conversion * of C comparison function return values into BinTree direction * values: {LEFT, PARENT, EQUAL}. It is INCORPORATED into the * AbNormal() conversion macro! * * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr ); /* ------------------------------------------------------------------------ ** * Initialize a tree node. * * Input: a pointer to a ubi_btNode structure to be initialized. * Output: a pointer to the initialized ubi_btNode structure (ie. the * same as the input pointer). * ------------------------------------------------------------------------ ** */ ubi_btRootPtr ubi_btInitTree( ubi_btRootPtr RootPtr, ubi_btCompFunc CompFunc, char Flags ); /* ------------------------------------------------------------------------ ** * Initialize the fields of a Tree Root header structure. * * Input: RootPtr - a pointer to an ubi_btRoot structure to be * initialized. * CompFunc - a pointer to a comparison function that will be used * whenever nodes in the tree must be compared against * outside values. * Flags - One bytes worth of flags. Flags include * ubi_trOVERWRITE and ubi_trDUPKEY. See the header * file for more info. * * Output: a pointer to the initialized ubi_btRoot structure (ie. the * same value as RootPtr). * * Note: The interface to this function has changed from that of * previous versions. The <Flags> parameter replaces two * boolean parameters that had the same basic effect. * ------------------------------------------------------------------------ ** */ ubi_trBool ubi_btInsert( 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 * 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_btRemove( 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_btLocate( 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_btFind( 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_btLocate(). * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btNext( ubi_btNodePtr P ); /* ------------------------------------------------------------------------ ** * Given the node indicated by P, find the (sorted order) Next node in the * tree. * Input: P - a pointer to a node that exists in a binary tree. * Output: A pointer to the "next" node in the tree, or NULL if P pointed * to the "last" node in the tree or was NULL. * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btPrev( ubi_btNodePtr P ); /* ------------------------------------------------------------------------ ** * Given the node indicated by P, find the (sorted order) Previous node in * the tree. * Input: P - a pointer to a node that exists in a binary tree. * Output: A pointer to the "previous" node in the tree, or NULL if P * pointed to the "first" node in the tree or was NULL. * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btFirst( ubi_btNodePtr P ); /* ------------------------------------------------------------------------ ** * Given the node indicated by P, find the (sorted order) First node in the * subtree of which *P is the root. * Input: P - a pointer to a node that exists in a binary tree. * Output: A pointer to the "first" node in a subtree that has *P as its * root. This function will return NULL only if P is NULL. * Note: In general, you will be passing in the value of the root field * of an ubi_btRoot structure. * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btLast( ubi_btNodePtr P ); /* ------------------------------------------------------------------------ ** * Given the node indicated by P, find the (sorted order) Last node in the * subtree of which *P is the root. * Input: P - a pointer to a node that exists in a binary tree. * Output: A pointer to the "last" node in a subtree that has *P as its * root. This function will return NULL only if P is NULL. * Note: In general, you will be passing in the value of the root field * of an ubi_btRoot structure. * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btFirstOf( ubi_btRootPtr RootPtr, ubi_btItemPtr MatchMe, ubi_btNodePtr p ); /* ------------------------------------------------------------------------ ** * Given a tree that a allows duplicate keys, and a pointer to a node in * the tree, this function will return a pointer to the first (traversal * order) node with the same key value. * * Input: RootPtr - A pointer to the root of the tree. * MatchMe - A pointer to the key value. This should probably * point to the key within node *p. * p - A pointer to a node in the tree. * Output: A pointer to the first node in the set of nodes with keys * matching <FindMe>. * Notes: Node *p MUST be in the set of nodes with keys matching * <FindMe>. If not, this function will return NULL. * * 4.7: Bug found & fixed by Massimo Campostrini, * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. * * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btLastOf( ubi_btRootPtr RootPtr, ubi_btItemPtr MatchMe, ubi_btNodePtr p ); /* ------------------------------------------------------------------------ ** * Given a tree that a allows duplicate keys, and a pointer to a node in * the tree, this function will return a pointer to the last (traversal * order) node with the same key value. * * Input: RootPtr - A pointer to the root of the tree. * MatchMe - A pointer to the key value. This should probably * point to the key within node *p. * p - A pointer to a node in the tree. * Output: A pointer to the last node in the set of nodes with keys * matching <FindMe>. * Notes: Node *p MUST be in the set of nodes with keys matching * <FindMe>. If not, this function will return NULL. * * 4.7: Bug found & fixed by Massimo Campostrini, * Istituto Nazionale di Fisica Nucleare, Sezione di Pisa. * * ------------------------------------------------------------------------ ** */ unsigned long ubi_btTraverse( ubi_btRootPtr RootPtr, ubi_btActionRtn EachNode, void *UserData ); /* ------------------------------------------------------------------------ ** * Traverse a tree in sorted order (non-recursively). At each node, call * (*EachNode)(), passing a pointer to the current node, and UserData as the * second parameter. * * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates * the tree to be traversed. * EachNode - a pointer to a function to be called at each node * as the node is visited. * UserData - a generic pointer that may point to anything that * you choose. * * Output: A count of the number of nodes visited. This will be zero * if the tree is empty. * * ------------------------------------------------------------------------ ** */ unsigned long ubi_btKillTree( ubi_btRootPtr RootPtr, ubi_btKillNodeRtn FreeNode ); /* ------------------------------------------------------------------------ ** * Delete an entire tree (non-recursively) and reinitialize the ubi_btRoot * structure. Return a count of the number of nodes deleted. * * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates * the root of the tree to delete. * FreeNode - a function that will be called for each node in the * tree to deallocate the memory used by the node. * * Output: The number of nodes removed from the tree. * A value of 0 will be returned if: * - The tree actually contains 0 entries. * - the value of <RootPtr> is NULL, in which case the tree is * assumed to be empty * - the value of <FreeNode> is NULL, in which case entries * cannot be removed, so 0 is returned. *Make sure that you * provide a valid value for <FreeNode>*. * In all other cases, you should get a positive value equal to * the value of RootPtr->count upon entry. * * ------------------------------------------------------------------------ ** */ ubi_btNodePtr ubi_btLeafNode( ubi_btNodePtr leader ); /* ------------------------------------------------------------------------ ** * Returns a pointer to a leaf node. * * Input: leader - Pointer to a node at which to start the descent. * * Output: A pointer to a leaf node, selected in a somewhat arbitrary * manner but with an effort to dig deep. * * Notes: I wrote this function because I was using splay trees as a * database cache. The cache had a maximum size on it, and I * needed a way of choosing a node to sacrifice if the cache * became full. In a splay tree, less recently accessed nodes * tend toward the bottom of the tree, meaning that leaf nodes * are good candidates for removal. (I really can't think of * any other reason to use this function.) * + In a simple binary tree, or in an AVL tree, the most recently * added nodes tend to be nearer the bottom, making this a *bad* * way to choose which node to remove from the cache. * + Randomizing the traversal order is probably a good idea. You * can improve the randomization of leaf node selection by passing * in pointers to nodes other than the root node each time. A * pointer to any node in the tree will do. Of course, if you * pass a pointer to a leaf node you'll get the same thing back. * + In an unbalanced splay tree, if you simply traverse downward * until you hit a leaf node it is possible to accidentally * stumble onto a short path. The result will be a leaf node * that is actually very high in the tree--possibly a very * recently accessed node. Not good. This function can follow * multiple paths in an effort to find a leaf node deeper * in the tree. Following a single path, of course, is the * fastest way to find a leaf node. A complete traversal would * be sure to find the deepest leaf but would be very costly in * terms of time. This function uses a compromise that has * worked well in testing. * * ------------------------------------------------------------------------ ** */ int ubi_btModuleID( 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. */ #define ubi_trItemPtr ubi_btItemPtr #define ubi_trNode ubi_btNode #define ubi_trNodePtr ubi_btNodePtr #define ubi_trRoot ubi_btRoot #define ubi_trRootPtr ubi_btRootPtr #define ubi_trCompFunc ubi_btCompFunc #define ubi_trActionRtn ubi_btActionRtn #define ubi_trKillNodeRtn ubi_btKillNodeRtn #define ubi_trSgn( x ) ubi_btSgn( x ) #define ubi_trInitNode( Np ) ubi_btInitNode( (ubi_btNodePtr)(Np) ) #define ubi_trInitTree( Rp, Cf, Fl ) \ ubi_btInitTree( (ubi_btRootPtr)(Rp), (ubi_btCompFunc)(Cf), (Fl) ) #define ubi_trInsert( Rp, Nn, Ip, On ) \ ubi_btInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \ (ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) ) #define ubi_trRemove( Rp, Dn ) \ ubi_btRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) ) #define ubi_trLocate( Rp, Ip, Op ) \ ubi_btLocate( (ubi_btRootPtr)(Rp), \ (ubi_btItemPtr)(Ip), \ (ubi_trCompOps)(Op) ) #define ubi_trFind( Rp, Ip ) \ ubi_btFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) #define ubi_trNext( P ) ubi_btNext( (ubi_btNodePtr)(P) ) #define ubi_trPrev( P ) ubi_btPrev( (ubi_btNodePtr)(P) ) #define ubi_trFirst( P ) ubi_btFirst( (ubi_btNodePtr)(P) ) #define ubi_trLast( P ) ubi_btLast( (ubi_btNodePtr)(P) ) #define ubi_trFirstOf( Rp, Ip, P ) \ ubi_btFirstOf( (ubi_btRootPtr)(Rp), \ (ubi_btItemPtr)(Ip), \ (ubi_btNodePtr)(P) ) #define ubi_trLastOf( Rp, Ip, P ) \ ubi_btLastOf( (ubi_btRootPtr)(Rp), \ (ubi_btItemPtr)(Ip), \ (ubi_btNodePtr)(P) ) #define ubi_trTraverse( Rp, En, Ud ) \ ubi_btTraverse((ubi_btRootPtr)(Rp), (ubi_btActionRtn)(En), (void *)(Ud)) #define ubi_trKillTree( Rp, Fn ) \ ubi_btKillTree( (ubi_btRootPtr)(Rp), (ubi_btKillNodeRtn)(Fn) ) #define ubi_trLeafNode( Nd ) \ ubi_btLeafNode( (ubi_btNodePtr)(Nd) ) #define ubi_trModuleID( s, l ) ubi_btModuleID( s, l ) /* ========================================================================== */ #endif /* UBI_BINTREE_H */