void avl() {
printf(">> AVL\n");
avl_tree_t tree;
avl_init(&tree, NULL);
test_avl_t a = { 1 };
test_avl_t b = { 2 };
test_avl_t c = { 3 };
avl_insert(&tree, &a.node, &test_avl_compare);
avl_insert(&tree, &b.node, &test_avl_compare);
avl_insert(&tree, &c.node, &test_avl_compare);
// Display them
avl_node_t *node = avl_head(&tree);
while (node) {
avl_node_t *next = avl_next(node);
avl_node_t *prev = avl_prev(node);
test_avl_t *c = avl_ref(node, test_avl_t, node);
test_avl_t *n = next ? avl_ref(next, test_avl_t, node) : NULL;
test_avl_t *p = prev ? avl_ref(prev, test_avl_t, node) : NULL;
printf("current: %d, next: %d, prev: %d\n",
c->number,
n ? n->number : -1,
p ? p->number : -1);
node = next;
}
}
struct avl_node* avl_search_smaller(struct avl_tree *tree,
struct avl_node *node,
avl_cmp_func *func)
// if an exact match does not exist,
// return greatest node smaller than NODE
{
struct avl_node *p = tree->root;
struct avl_node *pp = NULL;
int cmp;
while(p)
{
cmp = func(p, node, tree->aux);
pp = p;
if (cmp > 0) {
p = p->left;
}else if (cmp < 0){
p = p->right;
}else {
// search success
return p;
}
}
if (!pp) {
return pp;
}
cmp = func(pp, node, tree->aux);
if (cmp < 0) {
return pp;
}else{
return avl_prev(pp);
}
}
