Graphs: find a sink in less than O(|V|) - or show it can't be done

Question

I have a graph with n nodes as an adjacency matrix.

Is it possible to detect a sink in less than O(n) time?

If yes, how? If no

Answer 1

There are so many algorithms that shows how to find the universal sink in O(n) but they are so complex and couldn't be understood easily. I have found it on internet in paper that shows how to find a universal sink in O(n) very smoothly.

1) first create a "SINK" set consisting of all vertices of the graph also 
   create an adjacency list of the graph.
2) now choose first 2 elements of the set.
3) if(A(x,y)==1){
       remove x;             // remove x from "SINK" set.
     }else{
       remove y; }           //remove y from "SINK" set.B

By this algo you will end up with the sink node in your SINK set in "n-1" time. that is O(n) time.