本课程设计目的是实现树型目录结构文件系统，本人在实现过程中也利用二叉树，

其中每个节点都有父指针，子指针和兄弟指针，其中子指针指向该目录下的第一个子节点，而该子节点的父指针则指向它的上级目录。目录下各子节点用兄弟指针连接起来。

文件夹打开是则把文件夹名称及其地址压入打开文件夹栈，文件关闭则把文件夹名称及其地址从打开文件夹栈中抛出。

-This course is designed to achieve the directory tree structure, file system, I also used in the implementation process binary tree, where each node has a parent pointer, son and brother pointer pointer pointer to the directory where the child under the first sub- node, and the child node' s parent pointer points to its parent directory. Each sub-directory node pointer connected with the brothers. Open the folder put the folder name and address onto the stack, open the folder, the file is closed put the folder name and address from the stack throws open the folder.