lib/gl_avltree_list.c

   1 /* Sequential list data type implemented by a binary tree.
   2    Copyright (C) 2006, 2008-2020 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2006.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include "gl_avltree_list.h"
  22
  23 #include <stdlib.h>
  24
  25 /* -------------------------- gl_list_t Data Type -------------------------- */
  26
  27 /* Generic AVL tree code.  */
  28 #include "gl_anyavltree_list1.h"
  29
  30 /* Generic binary tree code.  */
  31 #include "gl_anytree_list1.h"
  32
  33 /* Generic AVL tree code.  */
  34 #include "gl_anyavltree_list2.h"
  35
  36 /* Generic binary tree code.  */
  37 #include "gl_anytree_list2.h"
  38
  39 /* For debugging.  */
  40 extern void gl_avltree_list_check_invariants (gl_list_t list);
  41
  42 static unsigned int _GL_ATTRIBUTE_PURE
  43 check_invariants (gl_list_node_t node, gl_list_node_t parent)
  44 {
  45   unsigned int left_height =
  46     (node->left != NULL ? check_invariants (node->left, node) : 0);
  47   unsigned int right_height =
  48     (node->right != NULL ? check_invariants (node->right, node) : 0);
  49   int balance = (int)right_height - (int)left_height;
  50
  51   if (!(node->parent == parent))
  52     abort ();
  53   if (!(node->branch_size
  54         == (node->left != NULL ? node->left->branch_size : 0)
  55            + 1 + (node->right != NULL ? node->right->branch_size : 0)))
  56     abort ();
  57   if (!(balance >= -1 && balance <= 1))
  58     abort ();
  59   if (!(node->balance == balance))
  60     abort ();
  61
  62   return 1 + (left_height > right_height ? left_height : right_height);
  63 }
  64
  65 void
  66 gl_avltree_list_check_invariants (gl_list_t list)
  67 {
  68   if (list->root != NULL)
  69     (void) check_invariants (list->root, NULL);
  70 }
  71
  72 const struct gl_list_implementation gl_avltree_list_implementation =
  73   {
  74     gl_tree_nx_create_empty,
  75     gl_tree_nx_create,
  76     gl_tree_size,
  77     gl_tree_node_value,
  78     gl_tree_node_nx_set_value,
  79     gl_tree_next_node,
  80     gl_tree_previous_node,
  81     gl_tree_get_at,
  82     gl_tree_nx_set_at,
  83     gl_tree_search_from_to,
  84     gl_tree_indexof_from_to,
  85     gl_tree_nx_add_first,
  86     gl_tree_nx_add_last,
  87     gl_tree_nx_add_before,
  88     gl_tree_nx_add_after,
  89     gl_tree_nx_add_at,
  90     gl_tree_remove_node,
  91     gl_tree_remove_at,
  92     gl_tree_remove,
  93     gl_tree_list_free,
  94     gl_tree_iterator,
  95     gl_tree_iterator_from_to,
  96     gl_tree_iterator_next,
  97     gl_tree_iterator_free,
  98     gl_tree_sortedlist_search,
  99     gl_tree_sortedlist_search_from_to,
 100     gl_tree_sortedlist_indexof,
 101     gl_tree_sortedlist_indexof_from_to,
 102     gl_tree_sortedlist_nx_add,
 103     gl_tree_sortedlist_remove
 104   };