二叉树的实现，做到了增加、删除、查找关键字的功能，可以打印整个二叉树，可以查找父节点。程序功能简单，清晰易懂，对指针的操作谨慎小心。-The realization of a binary tree, so the add, delete, find keyword feature, you can print the entire binary tree, you can find the parent node. Program features a simple, lucid, caref