/* glpavl.h (binary search tree) */

 /***********************************************************************

 *  This code is part of GLPK (GNU Linear Programming Kit).

 *

 *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

 *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,

 *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.

 *  E-mail: <mao@gnu.org>.

 *

 *  GLPK 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 3 of the License, or

 *  (at your option) any later version.

 *

 *  GLPK 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 GLPK. If not, see <http://www.gnu.org/licenses/>.

 ***********************************************************************/

 #ifndef GLPAVL_H

 #define GLPAVL_H

 #include "glpdmp.h"

 typedef struct AVL AVL;

 typedef struct AVLNODE AVLNODE;

 struct AVL

 {     /* AVL tree (Adelson-Velsky & Landis binary search tree) */

       DMP *pool;

       /* memory pool for allocating nodes */

       AVLNODE *root;

       /* pointer to the root node */

       int (*fcmp)(void *info, const void *key1, const void *key2);

       /* application-defined key comparison routine */

       void *info;

       /* transit pointer passed to the routine fcmp */

       int size;

       /* the tree size (the total number of nodes) */

       int height;

       /* the tree height */

 };

 struct AVLNODE

 {     /* node of AVL tree */

       const void *key;

       /* pointer to the node key (data structure for representing keys

          is supplied by the application) */

       int rank;

       /* node rank = relative position of the node in its own subtree =

          the number of nodes in the left subtree plus one */

       int type;

       /* reserved for the application specific information */

       void *link;

       /* reserved for the application specific information */

       AVLNODE *up;

       /* pointer to the parent node */

       short int flag;

       /* node flag:

          0 - this node is the left child of its parent (or this node is

              the root of the tree and has no parent)

          1 - this node is the right child of its parent */

       short int bal;

       /* node balance = the difference between heights of the right and

          left subtrees:

          -1 - the left subtree is higher than the right one;

           0 - the left and right subtrees have the same height;

          +1 - the left subtree is lower than the right one */

       AVLNODE *left;

       /* pointer to the root of the left subtree */

       AVLNODE *right;

       /* pointer to the root of the right subtree */

 };

 #define avl_create_tree _glp_avl_create_tree

 AVL *avl_create_tree(int (*fcmp)(void *info, const void *key1,

       const void *key2), void *info);

 /* create AVL tree */

 #define avl_strcmp _glp_avl_strcmp

 int avl_strcmp(void *info, const void *key1, const void *key2);

 /* compare character string keys */

 #define avl_insert_node _glp_avl_insert_node

 AVLNODE *avl_insert_node(AVL *tree, const void *key);

 /* insert new node into AVL tree */

 #define avl_set_node_type _glp_avl_set_node_type

 void avl_set_node_type(AVLNODE *node, int type);

 /* assign the type field of specified node */

 #define avl_set_node_link _glp_avl_set_node_link

 void avl_set_node_link(AVLNODE *node, void *link);

 /* assign the link field of specified node */

 #define avl_find_node _glp_avl_find_node

 AVLNODE *avl_find_node(AVL *tree, const void *key);

 /* find node in AVL tree */

 #define avl_get_node_type _glp_avl_get_node_type

 int avl_get_node_type(AVLNODE *node);

 /* retrieve the type field of specified node */

 #define avl_get_node_link _glp_avl_get_node_link

 void *avl_get_node_link(AVLNODE *node);

 /* retrieve the link field of specified node */

 #define avl_delete_node _glp_avl_delete_node

 void avl_delete_node(AVL *tree, AVLNODE *node);

 /* delete specified node from AVL tree */

 #define avl_delete_tree _glp_avl_delete_tree

 void avl_delete_tree(AVL *tree);

 /* delete AVL tree */

 #endif

 /* eof */