private AvlTreeNode <T> FindMin(AvlTreeNode <T> node)
{
if (node.GetLeft() == null)
{
return(node);
}
return(FindMin(node.GetLeft()));
}
private AvlTreeNode <T> Balance(AvlTreeNode <T> node)
{
if (node == null)
{
return(null);
}
int balance = ValidateHeight(node.GetLeft())
- ValidateHeight(node.GetRight());
if (balance == 2)
{
if (node.GetLeft().GetLeft() != null)
{
if (node == _root)
{
_root = node.GetLeft();
}
node = node.RotateLeftChild();
}
else
{
if (node == _root)
{
_root = node.GetLeft().GetRight();
}
node = node.RotateDoubleLeft();
}
}
else if (balance == -2)
{
if (node.GetRight().GetRight() != null)
{
if (node == _root)
{
_root = node.GetRight();
}
node = node.RotateRightChild();
}
else
{
if (node == _root)
{
_root = node.GetRight().GetLeft();
}
node = node.RotateDoubleRight();
}
}
node.CalculateHeight();
return(node);
}
private AvlTreeNode <T> SearchRecursive(T value, AvlTreeNode <T> node)
{
if (node == null)
{
return(null);
}
if (node.GetValue().CompareTo(value) > 0)
{
return(SearchRecursive(value, node.GetLeft()));
}
if (node.GetValue().CompareTo(value) < 0)
{
return(SearchRecursive(value, node.GetRight()));
}
return(node);
}
private AvlTreeNode <T> DeleteRecursive(T value, AvlTreeNode <T> node)
{
if (node == null)
{
return(null);
}
if (node.GetValue().CompareTo(value) > 0)
{
node.SetLeft(DeleteRecursive(value, node.GetLeft()));
}
else if (node.GetValue().CompareTo(value) < 0)
{
node.SetRight(DeleteRecursive(value, node.GetRight()));
}
else if (node.GetLeft() != null && node.GetRight() != null)
{
T replace = FindMin(node.GetRight()).GetValue();
node.SetValue(replace);
node.SetRight(DeleteRecursive(replace, node.GetRight()));
}
else
{
if (node == _root)
{
node = (node.GetLeft() == null) ? node.GetRight() : node.GetLeft();
_root = node;
}
else
{
node = (node.GetLeft() == null) ? node.GetRight() : node.GetLeft();
}
}
node = Balance(node);
return(node);
}