template<class KEY, class VALUE> int Nde::index_has_subtree () {
// return the element in this node's parent that has the "this" pointer as its subtree
if (!mp_parent)
return invalid_index;
int first = 0;
int last = mp_parent->m_count-1;
while (last-first > 1) {
int mid = first+(last-first)/2;
//Elem& smallest = smallest_key();
if (smallest_key()>=mp_parent->m_vector[mid])
first = mid;
else
last = mid;
}
if (mp_parent->m_vector[first].mp_subtree == this)
return first;
else if (mp_parent->m_vector[last].mp_subtree == this)
return last;
else
throw "error in index_has_subtree";
}
int index_has_subtree (PBTREE btree, int node_idx) {
// return the element in this node's parent that has the "this" pointer as its subtree
int first;
int last;
int parent_node_idx = btree->nodes[node_idx].parent_node_idx;
if (!BTREE_IS_VALID_NODE_IDX(parent_node_idx))
return BTREE_INVALID_NODE_IDX;
first = 0;
last = btree->nodes[parent_node_idx].element_count-1;
while (last-first > 1) {
int mid = first+(last-first)/2;
PBTREE_ELEMENT smallest = smallest_key(btree, node_idx);
if (smallest->key >= btree->nodes[parent_node_idx].elements[mid].key)
first = mid;
else
last = mid;
}
if (btree->nodes[parent_node_idx].elements[first].subtree_node_idx == node_idx)
return first;
else if (btree->nodes[parent_node_idx].elements[last].subtree_node_idx == node_idx)
return last;
else
return BTREE_INVALID_NODE_IDX;
}
