Design mkdir and ls for a Basic File System

# Design mkdir and ls for a Basic File System Produce a low-level design for a basic in-memory file system that supports mkdir and ls. Identify the core entities, their relationships, path-resolution behavior, and operation flow, and describe an entity or class diagram without writing a complete runnable implementation. ### Constraints & Assumptions - Paths are absolute and use a single root directory. - mkdir may need a clarified policy for missing parents and existing names. - ls must distinguish listing a directory from inspecting a file path. ### Clarifying Questions to Ask - Should mkdir create intermediate directories? - How should duplicate names or a file-directory name collision behave? - What ordering should ls use, and what should it return for a file path? ```hint Make path resolution shared Treat traversal and validation as one reusable responsibility rather than reimplementing it in every command. ``` ### What a Strong Answer Covers - File-system, directory, file, and node responsibilities. - Parent-child ownership, name uniqueness, and path invariants. - Stepwise mkdir and ls behavior, including error cases. - Complexity, extensibility, and a clear class relationship diagram. ### Follow-up Questions 1. How would you add move without corrupting parent-child relationships? 2. What changes if concurrent callers may modify the same directory?