AVL树左右旋转C＃

Question

我正在尝试实现一个AVL树，但是当我将树打印出来时，它什么也没做。我认为我的左右旋转实现有问题。

我已将两个变量“old”和“new”之间的旋转值转移到了更容易的位置。

      private void rotateLeft(ref Node<T> tree)
        {
            if (tree.Right.BalanceFactor > 0)
            {
                rotateRight(ref tree.Right);
            }
            Node<T> oldRoot = tree;
            Node<T> newRoot = tree;

            newRoot.Right = oldRoot;
            oldRoot.Left = newRoot;
            newRoot.Right = oldRoot.Left;

        }

        private void rotateRight(ref Node<T> tree)
        {
            if (tree.Left.BalanceFactor < 0)
            {
                rotateLeft(ref tree.Left);
            }
            Node<T> oldRoot = tree;
            Node<T> newRoot = tree;

            newRoot.Left = oldRoot;
            oldRoot.Right = newRoot;
            newRoot.Left = oldRoot.Right;


        }

继承节点BalanceFactor

class Node<T> where T : IComparable
{
    private T data;
    private int balanceFactor = 0; //added for AVLTree
    public Node<T> Left, Right;

    public int BalanceFactor
    {
        set { balanceFactor = value; }
        get { return balanceFactor; }
    }

插入项目

private void insertItem(T item, ref Node<T> tree)
        {
            if (tree == null)
                tree = new Node<T>(item);
            else if (item.CompareTo(tree.Data) < 0)
                insertItem(item, ref tree.Left);
            else if (item.CompareTo(tree.Data) > 0)
                insertItem(item, ref tree.Right);

            tree.BalanceFactor = Height(tree.Left) - Height(tree.Right);

            if (tree.BalanceFactor <= -2)
                rotateLeft(ref tree);
            if (tree.BalanceFactor >= 2)
                rotateRight(ref tree);
        }

Answer 1

看看这段代码：

Node<T> oldRoot = tree;
Node<T> newRoot = tree;

newRoot.Right = oldRoot;
oldRoot.Left = newRoot;
newRoot.Right = oldRoot.Left;

并尽可能填充tree。 ......这就是：

tree.Right = tree;
tree.Left = tree;
tree.Right = tree.Left;

我相当确定这不是你想要做的。请查看wikipedia处的AVL平衡算法。