What are the steps for deleting 16? 欲在以上二叉搜索树中删除节点16，可行的方案是：
Aremove 16, make 25 the right child of 10 and 10 becomes the new root.
将16摘除后令25为10的右子，从而10是新的根节点
Bexecute a zig operation on 16 making it no longer the root, and then remove it directly
以16为轴进行一次zig操作使之不再是根节点，再直接摘除16
Cexchange the key of node 16 and node 33, and remove the new node 16
将节点16和节点33的关键码互换，再摘除新的节点16
Dexchange the key of node 16 and node 15, remove the new node 16 and make 13 the right child of 11
将节点16和节点15的关键码互换，摘除新的节点16并令13为11的右子