Given a string consisting words. We have to take last word from the string. "Hi how are you?" "you?" should be taken

Implement stack data structure using array .

You are given a Employee table having emp_id,name,dept_id.etc where dept_id is refering to Department table haing attributes dept_id,dept_name. 1. Find dept_name of employees using both tables. 2. Some employees have not been assigned dept there entry in dept_id is NULL. So find the dept_name of employess having department and NULL entries.