Hacktoberfest 2021

Event details :

Hacktoberfest® is open to everyone in our global community. Whether you’re a developer, student learning to code, event host, or company of any size, you can help drive growth of open source and make positive contributions to an ever-growing community.
All backgrounds and skill levels are encouraged to complete the challenge.
Hacktoberfest is a celebration open to everyone in our global community.
You can sign up anytime between October 1 and October 31.

To earn your Hacktoberfest tee or tree reward, you must register and make four valid pull requests (PRs) between October 1-31 (in any time zone).
Pull requests can be made in any participating GitHub or GitLab hosted repository/project. Look for the 'hacktoberfest' topic to know if a repository/project is participating in Hacktoberfest.
Pull requests must be approved by a maintainer of the repository/project to count.
If a maintainer reports your pull request as spam or behavior not in line with the project’s code of conduct, you will be ineligible to participate.
This year, the first 55,000 participants who successfully complete the challenge will be eligible to receive a prize.

You can write solutions only in Java for Data Structure and Algorithms (if you dont know Java you can submit only algorithm)
Follow file naming convention for all your pull requests.
while adding any content it should be inside its appropiate directory
if there is any problem with inaccurate solution create a issue

use	file type	comments
questions	README.md	all questions of particular topic are mentioned in a `README.md` file inside the sub topic folder
Java solutions	[topic name].java	solution Java code file code to a question is written in same folder where question is mentioned
algorithm solution	[topic name]-algorithm.txt	algorithm solution to a question is written in a `.txt` txt file in same folder where question is mentioned

You can add a solution to a question ( present in the readme of particular topic folder) that is unanswered
you can update existing solution with a better one ( better complexity)
you can add new questions along with its solution
solve issue raised by other people or yourself
make webpage ( hosted from GitHub readme ) more appealing and updated
UI/UX of webpage

1. Fork this repo
2. Star this repo
3. Add a file ( txt/java ) inside appropriate folder 
4. commit the code
5. Make pull request

Beginner-friendly
Targeted for developers, content writers, and programming enthusiasts.
Would also help participants who are not familiar with development but are eager to participate in open source.