二叉搜尋樹插入演算法C#

public class BinaryTreeNode{    public BinaryTreeNode Left { get; set; }      public BinaryTreeNode Right { get; set; }      public int Data { get; set; }      public BinaryTreeNode(int data)    {        this.Data = data;    }}   public void InsertIntoBST(BinaryTreeNode root, int data)    {        BinaryTreeNode _newNode = new BinaryTreeNode(data);          BinaryTreeNode _current = root;        BinaryTreeNode _previous = _current;          while (_current != null)        {            if (data < _current.Data)            {                _previous = _current;                _current = _current.Left;            }            else if (data > _current.Data)            {                _previous = _current;                _current = _current.Right;            }        }          if (data < _previous.Data)            _previous.Left = _newNode;        else            _previous.Right = _newNode;    }

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