Added algorithm for finding index of rightmost set bit (#7234)

* Added algorithm for finding index of rightmost set bit

* applied suggested changes

* applied suggested changes

* Fixed failing Testcases

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>