I had this occasion many times. Fortunately or unfortunately, you referenced a question in which I have answered just after you. Yes indeed, my answer is just a continuation of yours and shows the same content. But be honest, I can say that, I didn't copy you. In fact, I didn't see your answer before I am posting mine.
When I answer a question, I will always try to give my answer in detail. I always think about future visitors and try to give an answer in a way they can benefit too. In the above case, you can see that, I have provided almost everything that needed for a helper class. So any one who go through that quesiton atleast understand what are the files that are dealing with a helper class.
This way, I think my answer gave an addition to your answer. It helped to complete your answer. Do you think I need to delete my answer ?
Most of the time I have colllision with @Marius. He is superfast. No one can beat him while answer. When I post my answer, he may get a tick for his answer. :). After I see his answer, if I feel that my answer is not required any more, then I deleted such answers. If my answer added a single point more to his answer, then normally I will request him to mention my answer on his answer.
So what I feel right in this context is,
1) Delete second post if it has the same exact content of the first answer
2) If the other answer possess atleast one additional point that is not in other answers, then it should not be deleted.
3) If you believe your answer is an add-on to the question and answer for that question get already accepted, then it would be good to request to the answered guy to mention your answer in his post or add that point to his answer itself.