Contributions are always welcome. Language doesn't matter. Just make sure you're implementing an algorithm.
PRs are welcome. To begin developing, follow the structure:
algorithm_name/language-name/file_name.extension e.g bubble_sort/python/bubble_sort.py
If there is an implementation of the same algorithm in your language, add your username in front of the file name.
Please include a description for the algorithm that you are implementing. It doesn't matter if it's copied from somewhere as long as it helps people that are learning new algorithm.
Graphical examples would be very helpful too.
Don't forget to include tests.
Don't remove previous implementations of algorithms. Just add a new file with your own implementation.
Beautify and cleanup your code for easier reading.