1 /* Ordered set data type implemented by a binary tree.
2 Copyright (C) 2006-2007 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2006.
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.
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.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Common code of gl_avltree_oset.c and gl_rbtree_oset.c. */
20 /* An item on the stack used for iterating across the elements. */
27 /* A stack used for iterating across the elements. */
28 typedef iterstack_item_t iterstack_t[MAXHEIGHT];
31 gl_tree_create_empty (gl_oset_implementation_t implementation,
32 gl_setelement_compar_fn compar_fn,
33 gl_setelement_dispose_fn dispose_fn)
35 struct gl_oset_impl *set = XMALLOC (struct gl_oset_impl);
37 set->base.vtable = implementation;
38 set->base.compar_fn = compar_fn;
39 set->base.dispose_fn = dispose_fn;
47 gl_tree_size (gl_oset_t set)
53 gl_tree_search (gl_oset_t set, const void *elt)
55 gl_setelement_compar_fn compar = set->base.compar_fn;
58 for (node = set->root; node != NULL; )
60 int cmp = (compar != NULL
61 ? compar (node->value, elt)
62 : (node->value > elt ? 1 :
63 node->value < elt ? -1 : 0));
70 /* We have an element equal to ELT. */
77 gl_tree_search_atleast (gl_oset_t set,
78 gl_setelement_threshold_fn threshold_fn,
79 const void *threshold,
84 for (node = set->root; node != NULL; )
86 if (! threshold_fn (node->value, threshold))
90 /* We have an element >= VALUE. But we need the leftmost such
92 gl_oset_node_t found = node;
94 for (; node != NULL; )
96 if (! threshold_fn (node->value, threshold))
104 *eltp = found->value;
111 static gl_oset_node_t
112 gl_tree_search_node (gl_oset_t set, const void *elt)
114 gl_setelement_compar_fn compar = set->base.compar_fn;
117 for (node = set->root; node != NULL; )
119 int cmp = (compar != NULL
120 ? compar (node->value, elt)
121 : (node->value > elt ? 1 :
122 node->value < elt ? -1 : 0));
129 /* We have an element equal to ELT. */
136 gl_tree_add (gl_oset_t set, const void *elt)
138 gl_setelement_compar_fn compar;
139 gl_oset_node_t node = set->root;
143 gl_tree_add_first (set, elt);
147 compar = set->base.compar_fn;
151 int cmp = (compar != NULL
152 ? compar (node->value, elt)
153 : (node->value > elt ? 1 :
154 node->value < elt ? -1 : 0));
158 if (node->right == NULL)
160 gl_tree_add_after (set, node, elt);
167 if (node->left == NULL)
169 gl_tree_add_before (set, node, elt);
180 gl_tree_remove (gl_oset_t set, const void *elt)
182 gl_oset_node_t node = gl_tree_search_node (set, elt);
185 return gl_tree_remove_node (set, node);
191 gl_tree_oset_free (gl_oset_t set)
193 /* Iterate across all elements in post-order. */
194 gl_oset_node_t node = set->root;
196 iterstack_item_t *stack_ptr = &stack[0];
200 /* Descend on left branch. */
205 stack_ptr->node = node;
206 stack_ptr->rightp = false;
210 /* Climb up again. */
213 if (stack_ptr == &stack[0])
216 node = stack_ptr->node;
217 if (!stack_ptr->rightp)
219 /* Free the current node. */
220 if (set->base.dispose_fn != NULL)
221 set->base.dispose_fn (node->value);
224 /* Descend on right branch. */
225 stack_ptr->rightp = true;
233 /* --------------------- gl_oset_iterator_t Data Type --------------------- */
235 static gl_oset_iterator_t
236 gl_tree_iterator (gl_oset_t set)
238 gl_oset_iterator_t result;
241 result.vtable = set->base.vtable;
243 /* Start node is the leftmost node. */
246 while (node->left != NULL)
249 /* End point is past the rightmost node. */
261 gl_tree_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
263 if (iterator->p != iterator->q)
265 gl_oset_node_t node = (gl_oset_node_t) iterator->p;
267 /* Advance to the next node. */
268 if (node->right != NULL)
271 while (node->left != NULL)
276 while (node->parent != NULL && node->parent->right == node)
288 gl_tree_iterator_free (gl_oset_iterator_t *iterator)