Devise and divide and conquer alogrithm and write psuedo code for the problem below...

A party of n guests, with one celebrity actor there, is going on down the street. We define a celebrity as a guest whom all other guests know, yet who knows no other guests. Specifically, if guest ai is the celebrity, aj 6= ai , knows(aj , ai) == true and knows(ai , aj) == f alse. Other guests may or may not know each other, as normal parties go. Give a O(n) algorithm which determines who the celebrity is