Designing an In-Memory File System — Dive into an Advanced Data Structure Problem

In this post, we will walk through a captivating problem from LeetCode: “588. Design In-Memory File System”.

📖 Problem Statement

We need to design an in-memory file system that can perform operations like creating folders, adding content to files, and retrieving content from files.

🔧 Intuitive Approach

When we think of a file system, a hierarchical structure like a tree comes to mind. For this problem, we can visualize the system as a Trie (a tree-like data structure). Each path component represents a Trie node, and each node can be a file or a directory.

📂 File System Structure

• Root directory exists at the inception.
• Each directory contains files and directories.
• Files can only contain content.

🛠 Optimal Approach and Design

1. Data Structure Choice: Use a Trie-like structure, where each Node represents a file or a directory.
2. Each Node Contains:
   - A flag indicating if it’s a file.
   - Content of the file (if it’s a file).
   - A HashMap to store child nodes (both files and directories).
3. Methods to Implement:
   ls: List the contents of the given path.
   mkdir: Create a new…