📚 Enterprise Library Management System

A modular, object-oriented Java application designed for library inventory control, fine tracking, and member subscription management. Built using advanced data structures ($O(1)$ HashMap lookups), date arithmetic for overdue calculations, and clean package architecture.

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🚀 Key Features

• $O(1)$ Inventory Search: Fast catalog lookups indexed by ISBN using Java HashMap data structures.
• Automated Fine Engine: Dynamic calculation of daily overdue fines ($2.50/day) based on return dates.
• Member Account Safeguards: Automated checkout blocks for members with outstanding fines exceeding account thresholds.
• Clean Package Architecture: Modular organization following production Java standards (com.library).

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🛠️ Project Structure

LibrarySystem/
└── src/
    └── com/
        └── library/
            ├── Book.java        # Entity model for book attributes and availability state
            ├── Member.java      # Profile model tracking borrowed items and unpaid fines
            ├── Library.java     # Core engine handling checkouts, returns, and fine logic
            └── LibraryApp.java  # Main application execution driver