avltr.h
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- /* libavl - manipulates AVL trees.
- Copyright (C) 1998, 1999 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
- This program 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
- General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
- 02111-1307, USA.
- The author may be contacted at <pfaffben@pilot.msu.edu> on the
- Internet, or as Ben Pfaff, 12167 Airport Rd, DeWitt MI 48820, USA
- through more mundane means. */
- /* This is file avltr.h in libavl. */
- #if !avltr_h
- #define avltr_h 1
- /* The default maximum height of 32 allows for AVL trees having
- between 5,704,880 and 4,294,967,295 nodes, depending on order of
- insertion. You may change this compile-time constant as you
- wish. */
- #ifndef AVL_MAX_HEIGHT
- #define AVL_MAX_HEIGHT 32
- #endif
- /* Structure for a node in a right-threaded AVL tree. */
- typedef struct avltr_node
- {
- void *data; /* Pointer to data. */
- struct avltr_node *link[2]; /* Subtrees or threads. */
- signed char bal; /* Balance factor. */
- char cache; /* Used during insertion. */
- char pad; /* Reserved for fully threaded trees. */
- signed char rtag; /* Right thread tag. */
- }
- avltr_node;
- /* Used for traversing a right-threaded AVL tree. */
- typedef struct avltr_traverser
- {
- int init; /* Initialized? */
- const avltr_node *p; /* Last node returned. */
- }
- avltr_traverser;
- /* Initializer for avltr_traverser. */
- #define AVLTR_TRAVERSER_INIT {0}
- /* Function types. */
- #if !AVL_FUNC_TYPES
- #define AVL_FUNC_TYPES 1
- typedef int (*avl_comparison_func) (const void *a, const void *b, void *param);
- typedef void (*avl_node_func) (void *data, void *param);
- typedef void *(*avl_copy_func) (void *data, void *param);
- #endif
- /* Structure which holds information about a threaded AVL tree. */
- typedef struct avltr_tree
- {
- avltr_node root; /* Tree root node. */
- avl_comparison_func cmp; /* Used to compare keys. */
- int count; /* Number of nodes in the tree. */
- void *param; /* Arbitary user data. */
- }
- avltr_tree;
- /* General functions. */
- avltr_tree *avltr_create (avl_comparison_func, void *param);
- void avltr_destroy (avltr_tree *, avl_node_func);
- void avltr_free (avltr_tree *);
- int avltr_count (const avltr_tree *);
- avltr_tree *avltr_copy (const avltr_tree *, avl_copy_func);
- struct avl_tree;
- avltr_tree *avltr_thread (struct avl_tree *);
- struct avl_tree *avltr_unthread (avltr_tree *);
- /* Walk the tree. */
- void avltr_walk (const avltr_tree *, avl_node_func, void *param);
- void *avltr_traverse (const avltr_tree *, avltr_traverser *);
- #define avlt_init_traverser(TRAVERSER) ((TRAVERSER)->init = 0)
- void **avltr_next (const avltr_tree *tree, void **item);
- /* Search for a given item. */
- void **avltr_probe (avltr_tree *, void *);
- void *avltr_delete (avltr_tree *, const void *);
- void **avltr_find (const avltr_tree *, const void *);
- void **avltr_find_close (const avltr_tree *, const void *);
- #if __GCC__ >= 2
- extern inline void *
- avltr_insert (avltr_tree *tree, void *item)
- {
- void **p = avltr_probe (tree, item);
- return (*p == item) ? NULL : *p;
- }
- extern inline void *
- avltr_replace (avltr_tree *tree, void *item)
- {
- void **p = avltr_probe (tree, item);
- if (*p == item)
- return NULL;
- else
- {
- void *r = *p;
- *p = item;
- return r;
- }
- }
- #else /* not gcc */
- void *avltr_insert (avltr_tree *tree, void *item);
- void *avltr_replace (avltr_tree *tree, void *item);
- #endif /* not gcc */
- /* Easy assertions on insertion & deletion. */
- #ifndef NDEBUG
- #define avltr_force_insert(A, B)
- do
- {
- void *r = avltr_insert (A, B);
- assert (r == NULL);
- }
- while (0)
- void *avltr_force_delete (avltr_tree *, void *);
- #else
- #define avltr_force_insert(A, B)
- avltr_insert (A, B)
- #define avltr_force_delete(A, B)
- avltr_delete (A, B)
- #endif
- #endif /* avltr_h */