MDO1铺设好了数据结构和主调函数。但是发现在输出显示目录和添加删除时比较麻烦，所以想改用结构体，双向链表和栈实现。

MDO2实现了用栈显示出当前路径

MDO3实现了cmd中输入路径名成查找到当前目录的问题。各种情况和cmd的路径一样。

MDO4实现了MD,MK，RD，DEL功能，但是只能在当前目录下操作创建删除文件夹。

-MDO1 laying of a good data structure and function of melody. However found in the output directory and add the show to delete relatively trouble, I want to switch to the structure, two-way linked list and stack to achieve. MDO2 achieved with Stack shows the current path MDO3 realized cmd enter into a search for a path to the current directory problems. Cmd various situations and the same path. MDO4 realized MD, MK, RD, DEL function, But only in the current directory operations to create delete folder.