unsigned int bst_c(bst *t, char c)
{
// base case: empty tree (end of the search)
if (t == NULL) {
return 0;
}
// recursive case 1: match found
// must go down both branches
if (c == t->c->cnet[0]) {
printf("%s\n", t->c->cnet);
return 1 + bst_c(t->lsub, c) + bst_c(t->rsub, c);
}
// recursive case 2: no match
// go down the correct branch
if (c < t->c->cnet[0]) {
return bst_c(t->lsub, c);
} else if (c > t->c->cnet[0]) {
return bst_c(t->rsub, c);
} else {
fprintf(stderr, "error in bst_c: impossible comparison\n");
exit(1);
}
}
/* shows all the cnets that start with the given char,
* in alphabetical order. returns the count of cnets displayed
*/
unsigned int bst_c(FILE *f, bst *t, char c) {
if(t == NULL)
return 0;
char* cnet = t -> c -> cnet;
int cmp = c - *cnet;
if(cmp == 0) {
int left = bst_c(f, t -> lsub, c);
fprintf(f, "%s\n", cnet);
int right = bst_c(f, t -> rsub, c);
return 1 + left + right;
}
if(cmp > 0)
return bst_c(f, t -> rsub, c);
return bst_c(f, t -> lsub, c);
}
/* curr_file pointer must point to a heap-allocated string */
int process_cmd(char **curr_file, char *cmd, bst **address_book, int *quit)
{
int parse_succeeded;
char *cnet;
char *infile;
char *first_char;
switch (cmd[0]) {
case 'q':
if (strcmp(cmd,"q")==0) {
*quit = 1;
return 1;
}
return 0;
case 's':
if (strcmp(cmd,"s")==0) {
if (strlen(*curr_file)>0)
fprintf(stdout,"Current file: %s.\n",*curr_file);
addr_book_stats(*address_book);
return 1;
}
return 0;
case 'r':
infile = extract_arg(cmd, &parse_succeeded);
if (parse_succeeded) {
bst *tmp = *address_book;
*address_book = admin_addr_book_from_file(infile);
if (*address_book==NULL) {
/* restore address book */
*address_book = tmp;
} else {
free(*curr_file);
*curr_file = infile;
bst_free(tmp);
}
}
return parse_succeeded;
case 'c':
first_char = extract_arg(cmd, &parse_succeeded);
if (parse_succeeded) {
if (strlen(first_char)!=1)
fprintf(stdout,"Please type exactly one character as argument to c.\n");
else {
unsigned int z = bst_c(*address_book, first_char[0]);
printf("(found %u CNETs starting with '%c')\n",z,first_char[0]);
}
putchar('\n');
free(first_char);
}
return parse_succeeded;
case 'l':
cnet = extract_arg(cmd, &parse_succeeded);
if (parse_succeeded) {
int n_comparisons = 0;
vcard *c = bst_search(*address_book, cnet, &n_comparisons);
if (c==NULL)
fprintf(stdout,"%s not found in current address book.\n", cnet);
else
vcard_show(c);
fprintf(stdout,"(Performed %d comparisons in search.)\n", n_comparisons);
putchar('\n');
}
free(cnet);
return parse_succeeded;
case 'h':
help_text();
return 1;
default:
return 0;
}
}
