/// <summary>Removes one occurrence of a specific element from the <see cref="AVLTree{T}" />. <code>Complexity: O(LogN)</code></summary>
/// <param name="value">The element to remove from the <see cref="AVLTree{T}"/>.</param>
/// <returns><c>true</c> if the element was successfully removed from the <see cref="AVLTree{T}"/>; <c>false</c> otherwise.</returns>
public bool Remove(T value)
{
if (!Find(value))
{
return(false);
}
AVLTreeNode <T> RemoveHelper(AVLTreeNode <T> node)
{
int comparison = Compare(value, node.Value);
if (comparison < 0)
{
node.LeftChildren--;
node.Left = RemoveHelper(node.Left);
}
else if (comparison > 0)
{
node.Right = RemoveHelper(node.Right);
}
else
{
if (node.Left == null)
{
return(node.Right);
}
if (node.Right == null)
{
return(node.Left);
}
node.Value = AVLTreeNode <T> .RemoveInOrderSuccessor(ref node.Right);
}
node.UpdateHeight();
node = node.PerformRotations();
return(node);
}
_root = RemoveHelper(_root);
Count--;
return(true);
}
/// <summary>Removes one occurrence of a specific element from the <see cref="AVLTree{T}" />. <code>Complexity: O(LogN)</code></summary>
/// <param name="value">The element to remove from the <see cref="AVLTree{T}"/>.</param>
/// <returns><c>true</c> if the element was successfully removed from the <see cref="AVLTree{T}"/>; <c>false</c> otherwise.</returns>
public override bool Remove(T value)
{
bool ret = true;
AVLTreeNode <T> RemoveHelper(AVLTreeNode <T> node)
{
if (node == null)
{
ret = false;
return(null);
}
int comparison = Compare(value, node.Value);
bool decremented = false;
if (comparison < 0)
{
node.LeftChildren--;
decremented = true;
node.Left = RemoveHelper(node.Left);
}
else if (comparison > 0)
{
node.Right = RemoveHelper(node.Right);
}
else
{
if (node.Left == null)
{
return(node.Right);
}
if (node.Right == null)
{
return(node.Left);
}
node.Value = AVLTreeNode <T> .RemoveInOrderSuccessor(ref node.Right);
}
if (ret)
{
node.UpdateHeight();
node = node.PerformRotations();
}
else if (decremented)
{
node.LeftChildren++;
}
return(node);
}
_root = RemoveHelper(_root);
if (ret)
{
Count--;
}
return(ret);
}