private void RotateLeft(TreeNode node, TraceNode parent)
{
var parentNode = parent.Node;
parentNode.Right = node.Left;
node.Left = parentNode;
if (parent.Parent != null)
{
if (parent.Dir == Direction.Left)
{
parent.Parent.Left = node;
}
else
{
parent.Parent.Right = node;
}
}
else // root
{
Root = node;
}
}
private void BalanceNode(TraceNode tn)
{
var curNode = tn.Node;
var bf = GetBalanceFactor(curNode);
if (bf == 2)
{
var left = curNode.Left;
var sbf = GetBalanceFactor(left);
if (sbf == -1) // left-right tree
{
RotateLeft(left.Right, new TraceNode()
{
Node = left, Parent = curNode, Dir = Direction.Right
});
}
// left-left tree
RotateRight(left, tn);
}
else if (bf == -2)
{
var right = curNode.Right;
var sbf = GetBalanceFactor(right);
if (sbf == 1) // right-left tree
{
RotateRight(Root.Left.Left, new TraceNode()
{
Node = right, Parent = curNode, Dir = Direction.Left
});
}
// right-right tree
RotateLeft(right, tn);
}
}
