/// <summary>
/// Recursive insertion with balancing on every step.
/// </summary>
private AVLTreeNode <T> Add(AVLTreeNode <T> node, T value)
{
if (node == null)
{
return(new AVLTreeNode <T>(value));
}
int cmp = comparer.Compare(value, node.Value);
if (cmp < 0)
{
node.Left = Add(node.Left, value);
}
else if (cmp > 0)
{
node.Right = Add(node.Right, value);
}
else
{
throw new ArgumentException("Tried to insert duplicate value!");
}
return(Balance(node));
}
/// <summary>
/// Calculates the balance factor.
/// </summary>
private int BalanceFactor(AVLTreeNode <T> node)
{
return(NodeHeight(node.Left) - NodeHeight(node.Right));
}
/// <summary>
/// Gets the node height. Returns 0 if node is null.
/// </summary>
private int NodeHeight(AVLTreeNode <T> node)
{
return(node?.Height ?? 0);
}