莫里斯·遍历是否多次访问一些节点？

Question

我正在求解 leetcode inorder tree traversal in ordor tree traversal 并实现了Morris traversal 在解决方案页面上建议。这是：

public class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    public TreeNode() {}
    public TreeNode(int val) { this.val = val; }
    public TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}

public static List<Integer> inorderTraversalMorris(TreeNode root){
    if(root == null){
        return Collections.emptyList();
    }
    List<Integer> result = new ArrayList<>();
    TreeNode current = root;
    while(current != null){
        if(current.left != null){
            TreeNode next = current.left;
            TreeNode appendTo = next;
            while(appendTo.right != null){
                appendTo = appendTo.right;
            }
            current.left = null;
            appendTo.right = current;
            current = next;
        } else {
            result.add(current.val);
            current = current.right;
        }
    }

    return result;
}

我看到的问题是，在将树重新平衡为螺纹二进制树时，算法访问了两次节点。有可能避免它吗？