http://www.mitbbs.com/article_t/JobHunting/33100463.html

System design
    a.    Output produce(Input input)
    b.    Output merge(Output o1, Output o2)
    c.    Now given a list of inputs List<Input> inputs, using k threads to
    generate the result. 
    d.    Queue, lock, thread safe and so on

any idea? Thanks,