二叉排序树的查找、插入和删除 要求：在屏幕上表示出二叉查找树的结构，用到的抽象数据类型为元素数据类型和二叉树结点类型。 -Binary sort tree search, insert, and delete requirements: binary search tree structure is shown on the screen, the abstract data types used for the element data type and the binary tree