simultaneous multiple key sorting algorithm

[Manfred Nowak]

Andrei Alexandrescu wrote:

> generally what one wants is a selection of "best of breed" stocks
> that are among the top ones in a variety of categories. (Relative
> importance could be assigned to each category.) 

This is quite different and easier than the problem initially stated, 
because ranks must not be computed.

1) Compute the individual importance `ii' of each element `e'  
2) Use the linear median algorithm to find the element `ek' whose 
individual importance `ii' is close to rank `k' of all elements `e', 
where `k' is the number of elements `e' acceptable as "best of the 
breed"
3) return all elements `e' whith `e.ii >= ek.ii'. This can be done by a 
sweep over the array.

-manfred