1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/***************************************************************************
aatree.c Copyright (C) 2006 Walter van Niftrik
This program may be modified and copied freely according to the terms of
the GNU general public license (GPL), as long as the above copyright
notice and the licensing information contained herein are preserved.
Please refer to www.gnu.org for licensing details.
This work is provided AS IS, without warranty of any kind, expressed or
implied, including but not limited to the warranties of merchantibility,
noninfringement, and fitness for a specific purpose. The author will not
be held liable for any damage caused by this work or derivatives of it.
By using this source code, you agree to the licensing terms as stated
above.
Please contact the maintainer for bug reports or inquiries.
Current Maintainer:
Walter van Niftrik [w.f.b.w.v.niftrik@stud.tue.nl]
***************************************************************************/
#include <stdlib.h>
#include <aatree.h>
#include <sci_memory.h>
struct aatree
{
struct aatree *left, *right;
int level;
void *key;
};
/* Sentinel node */
static aatree_t bottom = {&bottom, &bottom, 0, NULL};
static void
skew(aatree_t **t)
{
if ((*t)->left->level == (*t)->level) {
/* Rotate right */
aatree_t *temp = *t;
*t = (*t)->left;
temp->left = (*t)->right;
(*t)->right = temp;
}
}
static void
split(aatree_t **t)
{
if ((*t)->right->right->level == (*t)->level) {
/* Rotate left */
aatree_t *temp = *t;
*t = (*t)->right;
temp->right = (*t)->left;
(*t)->left = temp;
(*t)->level++;
}
}
static int
delete_node(void *x, aatree_t **t, aatree_t *deleted, int (*compar)(const void *, const void *))
{
int retval = -1;
if (*t != &bottom) {
/* Search down the tree */
aatree_t **n;
if (compar(x, (*t)->key) < 0)
n = &(*t)->left;
else {
n = &(*t)->right;
deleted = *t;
}
retval = delete_node(x, n, deleted, compar);
/* At the bottom of the tree we remove the element (if it is present) */
if ((*n == &bottom) && (deleted != &bottom) && (compar(x, deleted->key) == 0)) {
aatree_t *temp;
deleted->key = (*t)->key;
temp = *t;
*t = (*t)->right;
sci_free(temp);
retval = 0;
}
else if (((*t)->left->level < (*t)->level - 1) || ((*t)->right->level < (*t)->level - 1)) {
(*t)->level--;
if ((*t)->right->level > (*t)->level)
(*t)->right->level = (*t)->level;
skew(t);
skew(&(*t)->right);
skew(&(*t)->right->right);
split(t);
split(&(*t)->right);
}
}
return retval;
}
aatree_t *
aatree_new()
{
return ⊥
}
int
aatree_insert(void *x, aatree_t **t, int (*compar)(const void *, const void *))
{
int retval = -1;
int c;
if (*t == &bottom) {
*t = (aatree_t*)sci_malloc(sizeof(aatree_t));
if (*t == NULL)
return 1;
(*t)->key = x;
(*t)->left = ⊥
(*t)->right = ⊥
(*t)->level = 1;
return 0;
}
c = compar(x, (*t)->key);
if (c < 0)
retval = aatree_insert(x, &(*t)->left, compar);
else if (c > 0)
retval = aatree_insert(x, &(*t)->right, compar);
skew(t);
split(t);
return retval;
}
int
aatree_delete(void *x, aatree_t **t, int (*compar)(const void *, const void *))
{
return delete_node(x, t, &bottom, compar);
}
aatree_t *
aatree_walk(aatree_t *t, int direction)
{
if ((direction == AATREE_WALK_LEFT) && (t->left != &bottom))
return t->left;
if ((direction == AATREE_WALK_RIGHT) && (t->right != &bottom))
return t->right;
return NULL;
}
void *
aatree_get_data(aatree_t *t)
{
return t->key;
}
void
aatree_free(aatree_t *t)
{
if (t == &bottom)
return;
aatree_free(t->left);
aatree_free(t->right);
sci_free(t);
}
|
