Implemented Fast Inverse Sqrt Method

[ghost]

Describe your change:

• [x ] Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

References

Checklist:

• I have read CONTRIBUTING.md.
• [x ] This pull request is all my own work -- I have not plagiarized.
• [x ] I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• [ x] All new Java files are placed inside an existing directory.
• [x ] All filenames are in all uppercase characters with no spaces or dashes.
• [ x] All functions and variable names follow Java naming conventions.
• [ x] All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• [ x] If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[siriak]

The code looks good, could you add some automated tests as well?

[ghost]

The code looks good, could you add some automated tests as well?

I have just pushed my latest commit that consists of automated tests between both methods

[siriak]

Take a look at the files here https://github.com/TheAlgorithms/Java/tree/master/src/test/java/com/thealgorithms, main is an entry point and won't be run by a testing framework. It would help if you had JUnit tests https://www.vogella.com/tutorials/JUnit/article.html

[siddhant2002]

Can I work under this issue?

[siddhant2002]

@siriak Please check the pr

[siriak]

@siddhant2002 which PR?