Did you delete
/root/bin, or did you delete
If the former you shouldn't have lost anything (root should NEVER have "user binaries" in
~/bin - if you do you're doing it wrong and should stop).
If the latter (and that's really where MySQL is installed on your system), reinstall the MySQL package (as well as everything else you've undoubtedly destroyed int he process!) as Michael Hampton suggested.
This is a case where you should really be restoring the lost files from backups (and being WAY more careful with the
rm command in the future!). You happen to have lucked out, since as long as the MySQL data directory is safe all you need to do is get the binaries for the appropriate version of MySQL, install them appropriately, and start the MySQL server with your existing data directory.