public void Remove(int key)
{
if (key < _key)
{
_leftChild?.Remove(key);
return;
}
if (key > _key)
{
_rightChild?.Remove(key);
return;
}
bool isThisALeftChild = this == _parent.GetChild(true);
// No children case
if (GetChild(true) == null && GetChild(false) == null)
{
if (isThisALeftChild)
{
_parent.SetChild(null, true);
}
else
{
_parent.SetChild(null, false);
}
return;
}
// One child case
if (GetChild(true) == null || GetChild(false) == null)
{
if (GetChild(true) != null)
{
_parent.SetChild(GetChild(true), isThisALeftChild);
GetChild(true).SetParent(_parent);
return;
}
if (GetChild(false) != null)
{
_parent.SetChild(GetChild(false), isThisALeftChild);
GetChild(false).SetParent(_parent);
return;
}
}
// Both children case
// Finding the successor
BinaryTreeNode successorNode = _rightChild;
while (successorNode.GetChild(true) != null)
{
successorNode = successorNode.GetChild(true);
}
CopyFrom(successorNode);
// If the successor has no children
if (successorNode.GetChild(true) == null && successorNode.GetChild(false) == null)
{
if (successorNode == _rightChild)
{
SetChild(null, false);
}
else
{
successorNode.GetParent().SetChild(null, true);
}
return;
}
// The successor has a right child
if (successorNode == _rightChild)
{
SetChild(successorNode.GetChild(false), false);
}
else
{
successorNode.GetParent().SetChild(successorNode.GetChild(false), true);
successorNode.GetChild(false).SetParent(successorNode.GetParent());
}
}
private void CopyFrom(BinaryTreeNode node)
{
SetKey(node.GetKey());
SetValue(node.GetValue());
}
public void CreateChild(int key, string value, bool isLeft)
{
_root = new BinaryTreeNode(key, value, null);
}
public void SetChild(BinaryTreeNode newChild, bool isLeft)
{
_root = newChild;
}
public BinaryTree()
{
_root = null;
}