线索化中序、先序、后序遍历二叉树的方式(待补充完整)

public void morrisTraversal(TreeNode root){
TreeNode temp = null;
while(root!=null){
if(root.left!=null){
// connect threading for root
temp = root.left;
while(temp.right!=null && temp.right != root)
temp = temp.right;
// the threading already exists
if(temp.right!=null){
temp.right = null;
System.out.println(root.val);
root = root.right;
}else{
// construct the threading
temp.right = root;
root = root.left;
}
}else{
System.out.println(root.val);
root = root.right;
}
}
}