Sample Directed Graph and Topological Sort Code [closed]

Answer 1

Agree with jeremy.

I think here is a implementation to get the hashcode based on effective Java: http://www.javapractices.com/topic/TopicAction.do?Id=28

How about to add below method to override the hashcode?

@Override
    public int hashCode(){
         if (fHashCode == 0) {
              int result = HashCodeUtil.SEED;
              result = HashCodeUtil.hash(result, from);
              result = HashCodeUtil.hash(result, to);
         }
         return fHashCode;
    }