外部信息存储，外部信息的排序，多平衡归并的实现，最佳归并树-External information storage, external information of the sort, merge to achieve more balance, the best merge tree

二叉平衡树AVL的插入和删除的C实现源码，和大家分享一下，-Binary balanced tree insertion and deletion of the AVL implemented in C source code, and share with you, thank you