【PAT甲级】1066 Root of AVL Tree（25 分）（AVL数）_feng_zhiyu的博客

题目链接
An AVL tree is a self-balancing binary search tree. In an AVL tree, the heights of the two child subtrees of any node differ by at most one; if at any time they differ by more than one, rebalancing is done to restore this property. Figures 1-4 illustrate the rotation rules. An AVL tree is a self-balancing binary sea