Brian Schröäer wrote:
> It is possible to approximate knapsack (see scaled knapsack). But in
> this case we have a fixed and low number of cards, so it is possible to
> simply take on the combinatorial explosion and enumerate every solution.
>  
> The simplest implementation that uses only constant memory takes
> around three minutes for six cards on my machine.

I need a faster computer or a faster brain. I've got a brute force 
algorithm that appears to work, but it won't complete in anything like 
three minutes.

I guess I won't reveal the number until tomorrow, but my count of the 
distinct calculation expressions you can form with six numbers and four 
operators (not accounting for commutativity) is uhh... big.

Steve