bool TreeBalance(TreeElem *Tree)
{
if (Tree != NULL)
{
bool res = (abs(TreeDepth(Tree->LeftSon) - TreeDepth(Tree->RightSon)) <= 1);
return res && TreeBalance(Tree->LeftSon) && TreeBalance(Tree->RightSon);
}
else
return true;
}
/* TreeTraverseAndDelete -- traverse a tree while deleting nodes
*
* The visitor function must return TRUE to delete the current node,
* or FALSE to keep it.
*
* See <design/arena/#chunk.delete.tricky>.
*/
void TreeTraverseAndDelete(Tree *treeIO, TreeVisitor visitor,
void *closureP, Size closureS)
{
Tree *treeref = treeIO;
AVER(treeIO != NULL);
AVERT(Tree, *treeIO);
AVER(FUNCHECK(visitor));
/* closureP and closureS are arbitrary */
TreeToVine(treeIO);
while (*treeref != TreeEMPTY) {
Tree tree = *treeref; /* Current node. */
Tree *nextref = &tree->right; /* Location of pointer to next node. */
Tree next = *nextref; /* Next node. */
if ((*visitor)(tree, closureP, closureS)) {
/* Delete current node. */
*treeref = next;
} else {
/* Keep current node. */
treeref = nextref;
}
}
TreeBalance(treeIO);
}
void AVLTree::CorrectDeleteBalance(TreeNode* x)
{
// TreeBalance возвращает указатель на корень поворота
if ((x->balance == 2) || (x->balance == -2)) x = TreeBalance(x);
//баланс x уже поправлен, поправляем всех предков, пока
while ((x->balance != 1) && (x->balance != -1) && (x->parent != NULL))
{
//если удален слева
if (x == x->parent->left) x->parent->balance--;
//если удален справа
else x->parent->balance++;
if ((x->parent->balance == 2) || (x->parent->balance == -2))
{
x = TreeBalance(x->parent);
continue;
}
//на уровень выше
if (x->parent != NULL) x = x->parent;
}
}
void AVLTree::CorrectInsertBalance(TreeNode* x)
{
//баланс x уже поправлен
while ((x->balance != 0) && (x->balance != 2) && (x->balance != -2) && (x->parent != NULL))
{
//если x - левый узел
if (x == x->parent->left)
x->parent->balance++;
//если x - правый узел
else
x->parent->balance--;
x = x->parent;
}
if ((x->balance == 2) || (x->balance == -2)) TreeBalance(x);
}
bool BinnaryTree::BalancedTree(void)
{
return TreeBalance(Head);
}
