1 /* Ordered set data type implemented by a binary tree.
2 Copyright (C) 2006 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 2, or (at your option)
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, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19 /* Common code of gl_avltree_oset.c and gl_rbtree_oset.c. */
21 /* An item on the stack used for iterating across the elements. */
28 /* A stack used for iterating across the elements. */
29 typedef iterstack_item_t iterstack_t[MAXHEIGHT];
32 gl_tree_create_empty (gl_oset_implementation_t implementation,
33 gl_setelement_compar_fn compar_fn)
35 struct gl_oset_impl *set = XMALLOC (struct gl_oset_impl);
37 set->base.vtable = implementation;
38 set->base.compar_fn = compar_fn;
46 gl_tree_size (gl_oset_t set)
52 gl_tree_search (gl_oset_t set, const void *elt)
54 gl_setelement_compar_fn compar = set->base.compar_fn;
57 for (node = set->root; node != NULL; )
59 int cmp = (compar != NULL
60 ? compar (node->value, elt)
61 : (node->value > elt ? 1 :
62 node->value < elt ? -1 : 0));
69 /* We have an element equal to ELT. */
76 gl_tree_search_atleast (gl_oset_t set,
77 gl_setelement_threshold_fn threshold_fn,
78 const void *threshold,
83 for (node = set->root; node != NULL; )
85 if (! threshold_fn (node->value, threshold))
89 /* We have an element >= VALUE. But we need the leftmost such
91 gl_oset_node_t found = node;
93 for (; node != NULL; )
95 if (! threshold_fn (node->value, threshold))
103 *eltp = found->value;
110 static gl_oset_node_t
111 gl_tree_search_node (gl_oset_t set, const void *elt)
113 gl_setelement_compar_fn compar = set->base.compar_fn;
116 for (node = set->root; node != NULL; )
118 int cmp = (compar != NULL
119 ? compar (node->value, elt)
120 : (node->value > elt ? 1 :
121 node->value < elt ? -1 : 0));
128 /* We have an element equal to ELT. */
135 gl_tree_add (gl_oset_t set, const void *elt)
137 gl_setelement_compar_fn compar;
138 gl_oset_node_t node = set->root;
142 gl_tree_add_first (set, elt);
146 compar = set->base.compar_fn;
150 int cmp = (compar != NULL
151 ? compar (node->value, elt)
152 : (node->value > elt ? 1 :
153 node->value < elt ? -1 : 0));
157 if (node->right == NULL)
159 gl_tree_add_after (set, node, elt);
166 if (node->left == NULL)
168 gl_tree_add_before (set, node, elt);
179 gl_tree_remove (gl_oset_t set, const void *elt)
181 gl_oset_node_t node = gl_tree_search_node (set, elt);
184 return gl_tree_remove_node (set, node);
190 gl_tree_oset_free (gl_oset_t set)
192 /* Iterate across all elements in post-order. */
193 gl_oset_node_t node = set->root;
195 iterstack_item_t *stack_ptr = &stack[0];
199 /* Descend on left branch. */
204 stack_ptr->node = node;
205 stack_ptr->rightp = false;
209 /* Climb up again. */
212 if (stack_ptr == &stack[0])
215 node = stack_ptr->node;
216 if (!stack_ptr->rightp)
218 /* Free the current node. */
221 /* Descend on right branch. */
222 stack_ptr->rightp = true;
230 /* --------------------- gl_oset_iterator_t Data Type --------------------- */
232 static gl_oset_iterator_t
233 gl_tree_iterator (gl_oset_t set)
235 gl_oset_iterator_t result;
238 result.vtable = set->base.vtable;
240 /* Start node is the leftmost node. */
243 while (node->left != NULL)
246 /* End point is past the rightmost node. */
258 gl_tree_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
260 if (iterator->p != iterator->q)
262 gl_oset_node_t node = (gl_oset_node_t) iterator->p;
264 /* Advance to the next node. */
265 if (node->right != NULL)
268 while (node->left != NULL)
273 while (node->parent != NULL && node->parent->right == node)
285 gl_tree_iterator_free (gl_oset_iterator_t *iterator)