-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathtree.c
More file actions
268 lines (231 loc) · 6.16 KB
/
tree.c
File metadata and controls
268 lines (231 loc) · 6.16 KB
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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
/* tree.c -- tree support functions */
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "tree.h"
/* local data type */
typedef struct pair {
Node * parent;
Node * child;
} Pair;
/* protototypes for local functions */
static Node * MakeNode(const Item * pi);
static bool ToLeft(const Item * i1, const Item * i2);
static bool ToRight(const Item * i1, const Item * i2);
static void AddNode (Node * new_node, Node * root);
static void InOrder(const Node * root, void (* pfun)(Item item));
static Pair SeekItem(const Item * pi, const Tree * ptree);
static void DeleteNode(Node **ptr);
static void DeleteAllNodes(Node * ptr);
/* function definitions */
void InitializeTree(Tree * ptree)
{
ptree->root = NULL;
ptree->size = 0;
}
bool TreeIsEmpty(const Tree * ptree)
{
if (ptree->root == NULL)
return true;
else
return false;
}
bool TreeIsFull(const Tree * ptree)
{
if (ptree->size == MAXITEMS)
return true;
else
return false;
}
int TreeItemCount(const Tree * ptree)
{
return ptree->size;
}
bool AddItem(const Item * pi, Tree * ptree)
{
Node * new_node;
if (TreeIsFull(ptree))
{
fprintf(stderr,"Tree is full\n");
return false; /* early return */
}
if (SeekItem(pi, ptree).child != NULL)
{
fprintf(stderr, "Attempted to add duplicate item\n");
return false; /* early return */
}
new_node = MakeNode(pi); /* points to new node */
if (new_node == NULL)
{
fprintf(stderr, "Couldn't create node\n");
return false; /* early return */
}
/* succeeded in creating a new node */
ptree->size++;
if (ptree->root == NULL) /* case 1: tree is empty */
ptree->root = new_node; /* new node is tree root */
else /* case 2: not empty */
AddNode(new_node,ptree->root); /* add node to tree */
return true; /* successful return */
}
bool InTree(const Item * pi, const Tree * ptree)
{
return (SeekItem(pi, ptree).child == NULL) ? false : true;
}
bool DeleteItem(const Item * pi, Tree * ptree)
{
Pair look;
look = SeekItem(pi, ptree);
if (look.child == NULL)
return false;
if (look.parent == NULL) /* delete root item */
DeleteNode(&ptree->root);
else if (look.parent->left == look.child)
DeleteNode(&look.parent->left);
else
DeleteNode(&look.parent->right);
ptree->size--;
return true;
}
void Traverse (const Tree * ptree, void (* pfun)(Item item))
{
if (ptree != NULL)
InOrder(ptree->root, pfun);
}
void DeleteAll(Tree * ptree)
{
if (ptree != NULL)
DeleteAllNodes(ptree->root);
ptree->root = NULL;
ptree->size = 0;
}
/* local functions */
static void InOrder(const Node * root, void (* pfun)(Item item))
{
if (root != NULL)
{
InOrder(root->left, pfun);
(*pfun)(root->item);
InOrder(root->right, pfun);
}
}
static void DeleteAllNodes(Node * root)
{
Node * pright;
if (root != NULL)
{
pright = root->right;
DeleteAllNodes(root->left);
free(root);
DeleteAllNodes(pright);
}
}
static void AddNode (Node * new_node, Node * root)
{
if (ToLeft(&new_node->item, &root->item))
{
if (root->left == NULL) /* empty subtree */
root->left = new_node; /* so add node here */
else
AddNode(new_node, root->left);/* else process subtree*/
}
else if (ToRight(&new_node->item, &root->item))
{
if (root->right == NULL)
root->right = new_node;
else
AddNode(new_node, root->right);
}
else /* should be no duplicates */
{
fprintf(stderr,"location error in AddNode()\n");
exit(1);
}
}
static bool ToLeft(const Item * i1, const Item * i2)
{
int comp1;
if ((comp1 = strcmp(i1->petname, i2->petname)) < 0)
return true;
else if (comp1 == 0 &&
strcmp(i1->petkind, i2->petkind) < 0 )
return true;
else
return false;
}
static bool ToRight(const Item * i1, const Item * i2)
{
int comp1;
if ((comp1 = strcmp(i1->petname, i2->petname)) > 0)
return true;
else if (comp1 == 0 &&
strcmp(i1->petkind, i2->petkind) > 0 )
return true;
else
return false;
}
static Node * MakeNode(const Item * pi)
{
Node * new_node;
new_node = (Node *) malloc(sizeof(Node));
if (new_node != NULL)
{
new_node->item = *pi;
new_node->left = NULL;
new_node->right = NULL;
}
return new_node;
}
static Pair SeekItem(const Item * pi, const Tree * ptree)
{
Pair look;
look.parent = NULL;
look.child = ptree->root;
if (look.child == NULL)
return look; /* early return */
while (look.child != NULL)
{
if (ToLeft(pi, &(look.child->item)))
{
look.parent = look.child;
look.child = look.child->left;
}
else if (ToRight(pi, &(look.child->item)))
{
look.parent = look.child;
look.child = look.child->right;
}
else /* must be same if not to left or right */
break; /* look.child is address of node with item */
}
return look; /* successful return */
}
static void DeleteNode(Node **ptr)
/* ptr is address of parent member pointing to target node */
{
Node * temp;
puts((*ptr)->item.petname);
if ( (*ptr)->left == NULL)
{
temp = *ptr;
*ptr = (*ptr)->right;
free(temp);
}
else if ( (*ptr)->right == NULL)
{
temp = *ptr;
*ptr = (*ptr)->left;
free(temp);
}
else /* deleted node has two children */
{
/* find where to reattach right subtree */
for (temp = (*ptr)->left; temp->right != NULL;
temp = temp->right)
continue;
temp->right = (*ptr)->right;
temp = *ptr;
*ptr =(*ptr)->left;
free(temp);
}
}