Java Library

https://github.com/mjbullman/java-library

A comprehensive collection of data structures and algorithms implemented in Java, designed for learning, reference, and reuse.

Overview

This library provides clean, generic implementations of fundamental data structures and algorithms commonly encountered in computer science. All implementations use Java generics where applicable, with elements constrained by Comparable<T> for ordering operations.

Algorithms

Sorting

Algorithm	Time Complexity (Best)	Time Complexity (Avg)	Time Complexity (Worst)	Space Complexity
Bubble Sort	O(n)	O(n^2)	O(n^2)	O(1)
Selection Sort	O(n^2)	O(n^2)	O(n^2)	O(1)
Insertion Sort	O(n)	O(n^2)	O(n^2)	O(1)
Counting Sort	O(n + k)	O(n + k)	O(n + k)	O(k)

Searching

Algorithm	Time Complexity (Best)	Time Complexity (Avg)	Time Complexity (Worst)	Space Complexity
Linear Search	O(1)	O(n)	O(n)	O(1)
Binary Search	O(1)	O(log n)	O(log n)	O(1)

Data Structures

Heaps

Structure	Operations	Time Complexity
MinHeap	add, top, peek, remove, update, contains	O(log n) insert/delete, O(1) peek/contains
MaxHeap	add, top, peek, remove, update, contains	O(log n) insert/delete, O(1) peek/contains

Both heap implementations support a configurable branching factor (2-10) and use an internal index map for O(1) element lookup, enabling efficient remove() and update() operations.

Linked Lists

Structure	Description
Singly Linked List	Linear list with forward-only traversal
Doubly Linked List	Linear list with bidirectional traversal

Trees

Structure	Description
Binary Tree	Generic binary tree with level-order (BFS) insertion

Stacks

Structure	Description
Stack	LIFO stack backed by LinkedList
LinkedListStack	Stack extending base Stack with linked list backend

Queues

Structure	Description
Priority Queue	Priority-based queue using ArrayList

Utilities

Class	Description
StringUtils	String helpers: isEmpty, reverse, isPalindrome

Prerequisites

Before building the project, ensure you have the following installed:

• Java (JDK 11 or later)
• Maven (v3.x or later)

Installation

1. Clone the Repository

git clone https://github.com/mjbullman/java-library.git

2. Navigate to the Project Directory

cd java-library

3. Build the Project

mvn clean compile

Testing

Run all unit tests using JUnit 5:

mvn test

Run a specific test class:

mvn test -Dtest=BubbleSortTest

Run a specific test method:

mvn test -Dtest=BubbleSortTest#testBubbleSortIntegerArray

Linting

Run Checkstyle with Sun coding conventions:

mvn verify

Project Structure

src/
├── main/java/com/
│   ├── algorithms/
│   │   ├── graphs/          # Graph algorithms
│   │   ├── searching/       # Search algorithms
│   │   └── sorting/         # Sorting algorithms
│   ├── datastructures/
│   │   ├── heaps/           # Min and Max heap implementations
│   │   ├── linkedlists/     # Linked list variants
│   │   ├── queues/          # Queue implementations
│   │   ├── stacks/          # Stack implementations
│   │   └── trees/           # Tree implementations
│   ├── string/              # String utilities
│   └── utilities/           # General utilities
└── test/java/com/           # Unit tests (JUnit 5)

Contributing

Feel free to fork this repository, raise issues, or submit pull requests. Contributions are welcome and encouraged under the terms of the project's license.

Please ensure that your contributions follow the project's coding standards and guidelines. After forking, clone your copy of the repository, create a branch for your work, and submit a pull request for review.

License

This project is licensed under the MIT License. See the LICENSE file for details.