implemented a few algo myself

[ ] An issue was first created before opening this pull request
[ ] The new code follows the contribution guidelines
[ ] I have performed a self-review of my own code
[ ] I have commented my code, particularly in hard-to-understand areas
[ ] I have made corresponding changes to the documentation
[ ] My changes generate no new warnings
[ ] I have added tests to ensure that prove my fix is effective or that my feature works
[ ] New and existing unit tests pass locally with my changes

aalhour / C-Sharp-Algorithms