data_t bst_search(bst_t bst, index_t index) {
data_t data = NULL;
if (bst != NULL) {
if (index_is_equal(index, pair_fst(bst->pair))) {
data = pair_snd(bst->pair);
} else {
if (index_is_less_than(index, pair_fst(bst->pair))) {
data = bst_search(bst->left, index);
} else {
data = bst_search(bst->right, index);
}
}
}
return (data);
}
static unsigned int index_compare(index_t index, bst_t bst) {
if (index_is_equal(index, pair_fst(bst->pair))) {
return (EQ); /*Es igual... */
} else if (index_is_less_than(index, pair_fst(bst->pair))) {
return (LT); /*Es menor... */
} else {
return (GT); /*Es mayor... */
}
}
bst_t bst_add(bst_t bst, index_t index, data_t data) {
unsigned int prev_length = bst_length(bst);
if (bst != NULL) {
if (index_is_less_than(index, pair_fst(bst->pair))) {
bst->left = bst_add(bst->left, index, data);
} else if (!index_is_equal(index, pair_fst(bst->pair))) {
bst->right = bst_add(bst->right, index, data);
}
} else {
bst_t add = calloc(1, sizeof(struct _tree_node_t));
add->pair = pair_from_index_data(index, data);
add->left = NULL;
add->right = NULL;
bst = add;
}
assert(prev_length + 1 == bst_length(bst));
return bst;
}
bst_t bst_remove(bst_t bst, index_t index) {
bst_t current;
if (bst != NULL) {
if (index_is_less_than(index, pair_fst(bst->pair))) {
bst->left = bst_remove(bst->left, index);
} else if (index_is_equal(pair_fst(bst->pair), index) &&
bst->left == NULL) {
current = bst->right;
bst->pair = pair_destroy(bst->pair);
free(bst);
bst = current;
} else if (index_is_equal(pair_fst(bst->pair), index) &&
bst->left != NULL) {
bst->pair = pair_destroy(bst->pair);
bst->pair = bst_max(bst->left);
bst->left = delete_max(bst->left);
} else {
bst->right = bst_remove(bst->right, index);
}
}
return (bst);
}
