FileSystem

Write a program that simulate a file system. A file system is a tree structure that contains Folders and Files. At the top, there is a root folder. A folder can contain several Folder and several Files.

1. the user should have the possibility to ask for a folder structure. Each level of depth sould be materialized by tabulation and displayed on a new line. For a given level of depth, all the components should be ordered alphabetically on their names.

Exemple :

Root
    File1
    Folder1
        File2
        File3
        Folder2