/* * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) * Copyright (C) 2003-2008 Benny Prijono * * 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 */ #ifndef __PJ_RBTREE_H__ #define __PJ_RBTREE_H__ /** * @file rbtree.h * @brief Red/Black Tree */ #include PJ_BEGIN_DECL /** * @defgroup PJ_RBTREE Red/Black Balanced Tree * @ingroup PJ_DS * @brief * Red/Black tree is the variant of balanced tree, where the search, insert, * and delete operation is \b guaranteed to take at most \a O( lg(n) ). * @{ */ /** * Color type for Red-Black tree. */ typedef enum pj_rbcolor_t { PJ_RBCOLOR_BLACK, PJ_RBCOLOR_RED } pj_rbcolor_t; /** * The type of the node of the R/B Tree. */ typedef struct pj_rbtree_node { /** Pointers to the node's parent. */ struct pj_rbtree_node *parent; /** Pointers to the node's left sibling. */ struct pj_rbtree_node *left; /** Pointers to the node's right sibling. */ struct pj_rbtree_node *right; /** Key associated with the node. */ const void *key; /** User data associated with the node. */ void *user_data; /** The R/B Tree node color. */ pj_rbcolor_t color; } pj_rbtree_node; /** * The type of function use to compare key value of tree node. * @return * 0 if the keys are equal * <0 if key1 is lower than key2 * >0 if key1 is greater than key2. */ typedef int pj_rbtree_comp(const void *key1, const void *key2); /** * Declaration of a red-black tree. All elements in the tree must have UNIQUE * key. * A red black tree always maintains the balance of the tree, so that the * tree height will not be greater than lg(N). Insert, search, and delete * operation will take lg(N) on the worst case. But for insert and delete, * there is additional time needed to maintain the balance of the tree. */ typedef struct pj_rbtree { pj_rbtree_node null_node; /**< Constant to indicate NULL node. */ pj_rbtree_node *null; /**< Constant to indicate NULL node. */ pj_rbtree_node *root; /**< Root tree node. */ unsigned size; /**< Number of elements in the tree. */ pj_rbtree_comp *comp; /**< Key comparison function. */ } pj_rbtree; /** * Guidance on how much memory required for each of the node. */ #define PJ_RBTREE_NODE_SIZE (sizeof(pj_rbtree_node)) /** * Guidance on memory required for the tree. */ #define PJ_RBTREE_SIZE (sizeof(pj_rbtree)) /** * Initialize the tree. * @param tree the tree to be initialized. * @param comp key comparison function to be used for this tree. */ PJ_DECL(void) pj_rbtree_init( pj_rbtree *tree, pj_rbtree_comp *comp); /** * Get the first element in the tree. * The first element always has the least value for the key, according to * the comparison function. * @param tree the tree. * @return the tree node, or NULL if the tree has no element. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_first( pj_rbtree *tree ); /** * Get the last element in the tree. * The last element always has the greatest key value, according to the * comparison function defined for the tree. * @param tree the tree. * @return the tree node, or NULL if the tree has no element. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_last( pj_rbtree *tree ); /** * Get the successive element for the specified node. * The successive element is an element with greater key value. * @param tree the tree. * @param node the node. * @return the successive node, or NULL if the node has no successor. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_next( pj_rbtree *tree, pj_rbtree_node *node ); /** * The the previous node for the specified node. * The previous node is an element with less key value. * @param tree the tree. * @param node the node. * @return the previous node, or NULL if the node has no previous node. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_prev( pj_rbtree *tree, pj_rbtree_node *node ); /** * Insert a new node. * The node will be inserted at sorted location. The key of the node must * be UNIQUE, i.e. it hasn't existed in the tree. * @param tree the tree. * @param node the node to be inserted. * @return zero on success, or -1 if the key already exist. */ PJ_DECL(int) pj_rbtree_insert( pj_rbtree *tree, pj_rbtree_node *node ); /** * Find a node which has the specified key. * @param tree the tree. * @param key the key to search. * @return the tree node with the specified key, or NULL if the key can not * be found. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_find( pj_rbtree *tree, const void *key ); /** * Erase a node from the tree. * @param tree the tree. * @param node the node to be erased. * @return the tree node itself. */ PJ_DECL(pj_rbtree_node*) pj_rbtree_erase( pj_rbtree *tree, pj_rbtree_node *node ); /** * Get the maximum tree height from the specified node. * @param tree the tree. * @param node the node, or NULL to get the root of the tree. * @return the maximum height, which should be at most lg(N) */ PJ_DECL(unsigned) pj_rbtree_max_height( pj_rbtree *tree, pj_rbtree_node *node ); /** * Get the minumum tree height from the specified node. * @param tree the tree. * @param node the node, or NULL to get the root of the tree. * @return the height */ PJ_DECL(unsigned) pj_rbtree_min_height( pj_rbtree *tree, pj_rbtree_node *node ); /** * @} */ PJ_END_DECL #endif /* __PJ_RBTREE_H__ */