From: Admin Tensor Date: 2012-05-24T08:09:32+09:00 Subject: Re: Memory-efficient set of Fixnums Ryan Davis wrote in post #1061877: > Also... smells like homework. > > But if not, it reminds me of this article: > > http://highscalability.com/blog/2012/4/5/big-data-counting-how-to-count-a-billion-distinct-objects-us.html Hi, Whether it is a homework or not, it is a very realistic problem that we may encounter in our daily programming. The article is about using probabilistic algorithms with some level of error. I think we all assumed that the original poster wants an error of zero. (If the problem could not be solved using several gigabytes of RAM, or if the computation time took too long, then probabilistic algorithms ought to be considered.) Regards, Bill -- Posted via http://www.ruby-forum.com/.