Task Scheduler

Overview

This project is used to let you queue, process, undo, and inspect tasks in real time.
Under the hood it showcases classic data‑structure interplay:

Structure	Role	File
Queue (FIFO)	Holds pending tasks, sorted by arrival order	queue.c / queue.h
Stack (LIFO)	Holds completed tasks so the last one can be undone instantly	stack.c / stack.h

The program’s modular design (separate headers for the scheduler core, queue, stack, and utility helpers) makes it easy to extend—e.g., add persistence, deadlines, or different scheduling policies.

Key Features

Menu #	Action	What Happens
1	Add a Task	Collects a task name + priority (1‑5). Rejects empty or duplicate names.
2	Process a Task	Dequeues the next pending job, echoes it, then pushes it onto the completed stack.
3	Undo Last Completed	Pops the stack and re‑queues the item so it becomes pending again.
4	View Pending	Pretty prints the queue with running numbers and priorities.
5	View Completed	Shows the stack (top → bottom) so you can track all finished work.
6	Exit	Frees every dynamically allocated node in both structures before terminating.

Why You Might Like the Code

• Pure C11 – no third‑party libraries, ready for GCC, Clang, or MSVC.
• Safety First – every malloc checked, every fgets trimmed, priorities ranged 1‑5.
• Undo Without Drama – the stack/queue combo demonstrates clear separation of concerns.
• Teaching‐Ready – perfect for labs on linked lists, stacks, queues, or menu‑driven UIs.

Building & Running

Windows User:

1. Download VS Code and C/C++ Extension in VS Code.
2. Download MinGW. Link: https://sourceforge.net/projects/mingw/
3. In Terminal, type gcc Book_Catalog.c -o Book_Catalog.exe for compile the program and build the executable.
4. In Terminal, type .\Book_Catalog.exe to run the program.

Mac User:

1. Open Terminal, type xcode-select --install to install the Command Line Tools.
2. In Terminal, type gcc Book_Catalog.c -o Book_Catalog for compile the prgram and build the executable.
3. Lastly, type ./Book_Catalog to run the program.

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Feel free to fork and add advanced scheduling algorithms or persistence.