Page 182 - ARM 64 Bit Assembly Language
P. 182
Abstract data types 169
8 /**********************************************************/
9 /* The wordlistnode type is a binary tree of words and */
10 /* the number of times each word has occurred. */
11 typedef struct wlist_node{
12 char *word;
13 int count;
14 struct wlist_node *left, *right;
15 int height;
16 }wordlistnode;
17
18 /*********************************************************/
19 /* wln_alloc allocates and initializes a wordlistnode */
20 wordlistnode *wln_alloc(char *word)
21 {
22 wordlistnode *newword;
23 newword = (wordlistnode*)malloc(sizeof(wordlistnode));
24 if(newword == NULL)
25 {
26 printf("Unable to allocate wordlistnode\n");
27 exit(1);
28 }
29 newword->word = strdup(word);
30 newword->count = 1;
31 newword->left = NULL;
32 newword->right = NULL;
33 newword->height = 1;
34 return newword;
35 }
36
37 /*********************************************************/
38 /* wln_free frees the storage of a wordlistnode */
39 void wln_free(wordlistnode *root)
40 {
41 if(root == NULL)
42 return;
43 free(root->word);
44 wln_free(root->left);
45 wln_free(root->right);
46 free(root);
47 }
48
49 /*********************************************************/
50 /* wln_lookup is used to search the tree of words. It */
51 /* returns a pointer to the wordlistnode. If the word is */
52 /* not in the list, then it returns NULL. */
53 wordlistnode* wln_lookup(wordlistnode* root, char *word)
54 {
55 int cmp;
56 if(root != NULL)
