Design In-Memory File System

Statement

Design an in-memory file system. The skeleton for the class FileSystem is provided to you. Simulate the following functions:

• ls(String path): If path is a file path, return a list that only contains the file’s name. If it’s a directory path, return the list of files and directory names in this directory. Your function should return the output (file and directory names together) in lexicographical order.

• Void mkdir(String path): If the given path ...