Filtering Redundant Folder References

You are reorganizing a data warehouse in your company, working with a filesystem that creates parent folders if you give it a reference for a child folder. For example, if you ask the filesystem to create “folder1/folder2” and neither folder1 or folder2 exist, it will create both, with folder2 inside folder1, without raising an error. Given a list of folders, you want to keep only the longest unique child folders, filtering out references to parent folders that will be generated anyway for efficiency.