Design an In-Memory File System

Problem

Design an in-memory file system with path resolution.

Requirements

• mkdir, addContentToFile, readContentFromFile, ls
• Absolute paths /a/b/c
• Files vs directories

What evaluators look for

• Tree of nodes; clean path resolution
• Separation of structure vs content
• Edge cases (existing path, file-as-dir)

Extension

Add symlinks; discuss cycle prevention.