Java Stack and Queue Simulator

Overview

This Java application is designed to simulate the operations of a stack and a queue using a custom linked list implementation. The project is based on the LinkedList206 class structure from the CIS 206 class taught by Geoffrey Draper and is intended for educational purposes to demonstrate the manipulation and improvement of existing code.

Features

• Custom Stack Implementation: Utilizes a custom linked list to simulate stack operations such as push, pop, clear, and print.
• Custom Queue Implementation: Adapts the linked list to function as a queue with enqueue, dequeue, clear, and print operations.
• Standard Input Parsing: Parses commands and data from standard input (System.in).

How to Use

Stack Operations:

• PUSH n: Pushes "n" onto the top of the stack.
• POP: Removes and prints the top item of the stack. Prints "empty" if the stack is empty.
• CLEAR: Clears the stack.
• PRINT: Prints the current stack contents.

Queue Operations:

• ENQUEUE n: Adds "n" to the tail of the queue.
• DEQUEUE: Removes and prints the item from the head of the queue. Prints "empty" if the queue is empty.
• CLEAR: Clears the queue.
• PRINT: Prints the current queue contents.

Ending Input:

• Input ends with a line containing three asterisks ***.

Example for Stacks

Input:

PUSH 5
PUSH 10
PUSH 7
PUSH 90
POP
POP
PRINT
CLEAR
POP
PUSH 3
PUSH 67
POP
PUSH 22
POP
POP
POP
***

Output:

90
7
5
10
empty
67
22
3
empty

Sample input files (stack1.txt, stack2.txt, stack3.txt) and their expected outputs are available for testing.

Example for Queues

Input:

ENQUEUE 5
ENQUEUE 10
ENQUEUE 7
ENQUEUE 90
DEQUEUE
DEQUEUE
PRINT
CLEAR
DEQUEUE
ENQUEUE 3
ENQUEUE 67
DEQUEUE
ENQUEUE 22
DEQUEUE
DEQUEUE
DEQUEUE
***

Output:

5
10
7
90
empty
3
67
22
empty

Sample input files (queue1.txt, queue2.txt, queue3.txt...) and their expected outputs are available for testing.

Classes and Methods

• Stack<T>: Generic stack class with methods for stack operations.
• Queue<T>: Generic queue class with methods for queue operations.
• CustomLinkedList<T>: Custom implementation of a singly linked list used by both stack and queue.
• Node<T>: Represents a single element in the linked list.

Contributing

Contributions to improve the code or add new features are welcome. Please ensure to follow the existing coding style.