Need algorithm for Sequence calculation

Question

I am trying to find the solution for a problem where i have something like

1. A > B
2. B > C
3. B > D
4. C > D

And I should get the answer as A > B > C > D.

Conditions for this problem

1. The output will involve all the elements.
2. The problem will not have any bogus inputs. for example, (A>B) (C>D) is a bogus input, since we cannot determine the output.
3. The inputs can be of any size but never bogus and there will always be a solution to the problem.

I need to find a solution for this optimally using Java Collections. Any tips/hints are welcome.

Thanks in advance!

Answer 1

It's called a Topological Sort. http://en.wikipedia.org/wiki/Topological_sorting

Given that, you should be able to complete your homework on your own.