public AVLNode(T val, AVLNode <T> leftNode = null, AVLNode <T> rightNode = null, AVLNode <T> parent = null)
{
this.val = val;
left = leftNode;
right = rightNode;
}
public AVLTree(T firstNodeVal)
{
topNode = new AVLNode <T>(firstNodeVal);
}
/* public IEnumerable<AVLNode<T>> InOrder()
* {
* AVLNode<T> tempNode = topNode;
* while (tempNode != null)
* {
* yield return tempNode;
*
* }
* }
*/
void RotationLoop(AVLNode <T> newItem)
{
var me = newItem;
while (me != null)
{
if (me.Balance > 1)
{
var child = me.right;
if (child.Balance >= 0)
{
//left rot!
Console.WriteLine("Doing a left rotation!");
child.right = me.right?.right;
if (me.right.right != null)
{
me.right.right.parent = child;
}
me.right = child.left;
if (child.left != null)
{
child.left.parent = me;
}
if (me.parent == null)
{
topNode = child;
}
else
{
if (me.parent.left == me)
{
me.parent.left = child;
}
else if (me.parent.right == me)
{
me.parent.right = child;
}
else
{
throw new Exception("Luke... I'm... Not... Your... Father!");
}
}
child.parent = me.parent;
child.left = me;
me.parent = child;
}
else
{
//left right rot!
Console.WriteLine("Doing a left right rot!");
var grandchild = child.left;
var greatchildright = grandchild.right;
grandchild.right = child;
child.parent = grandchild;
child.left = greatchildright;
if (greatchildright != null)
{
greatchildright.parent = child;
}
child = grandchild;
me.right = child;
child.parent = me;
//now rotate left
child.right = me.right?.right;
if (me.right.right != null)
{
me.right.right.parent = child;
}
me.right = child.left;
if (child.left != null)
{
child.left.parent = me;
}
if (me.parent == null)
{
topNode = child;
}
else
{
if (me.parent.left == me)
{
me.parent.left = child;
}
else if (me.parent.right == me)
{
me.parent.right = child;
}
else
{
throw new Exception("Luke... I'm... Not... Your... Father!");
}
}
child.parent = me.parent;
child.left = me;
me.parent = child;
}
}
if (me.Balance < -1)
{
var child = me.left;
if (child.Balance <= 0)
{
//right rot!
Console.WriteLine("Doing a right rotation!");
child.left = me.left?.left;
if (me.left.left != null)
{
me.left.left.parent = child;
}
me.left = child.right;
if (child.right != null)
{
child.right.parent = me;
}
if (me.parent == null)
{
topNode = child;
}
else
{
if (me.parent.left == me)
{
me.parent.left = child;
}
else if (me.parent.right == me)
{
me.parent.right = child;
}
else
{
throw new Exception("Luke... I'm... Not... Your... Father!");
}
}
child.parent = me.parent;
child.right = me;
me.parent = child;
}
else
{
//right left rot!
Console.WriteLine("Doing a right left rot!");
var grandchild = child.right;
var greatchildleft = grandchild.left;
grandchild.left = child;
child.parent = grandchild;
child.right = greatchildleft;
if (greatchildleft != null)
{
greatchildleft.parent = child;
}
child = grandchild;
me.left = child;
child.parent = me;
//now rotate right
child.left = me.left?.left;
if (me.left.left != null)
{
me.left.left.parent = child;
}
me.left = child.right;
if (child.right != null)
{
child.right.parent = me;
}
if (me.parent == null)
{
topNode = child;
}
else
{
if (me.parent.left == me)
{
me.parent.left = child;
}
else if (me.parent.right == me)
{
me.parent.right = child;
}
else
{
throw new Exception("Luke... I'm... Not... Your... Father!");
}
}
child.parent = me.parent;
child.right = me;
me.parent = child;
}
}
me = me.parent;
}
}
public AVLTree()
{
topNode = null;
}