An interesting problem

[Andy Armstrong]

On 3 Jan 2007, at 20:10, McGlinchy, Alistair wrote:
> That's sort of what I have been playing with, but it still doesn't  
> seem
> impressively fast. There's a large number of off-by-one errors  
> possible
> in here, but the answers seems to tally up when I check in Excel.

Another thing you can do is have the quadtree (or whatever structure  
you build) record the minima and maxima for each region. That'll  
might allow you to discount some regions (too negative) without  
having to sum them.

-- 
Andy Armstrong, hexten.net