The editorial for SRM 585 is complete: http://apps.topcoder.com/wiki/display/tc/SRM+585#EnclosingTriangle
I really wanted a faster release this time, but I couldn't receive the explanation on how to solve this problem until late in the week. I think it is my fault, because I think I could have done it if I didn't wait for it. I should stop limiting myself like that.
I finished the algorithm. I thought it was a cute `O(m)` algorithm, and it seemed like a good idea to explain. I definitely don't understand how to use segment trees (I have no idea how to use them in general, or how they work). And I can't decipher tourist's solution. So this was the best I had... But while writing this I figured that this is a very confusing solution. Although I think it is simple, it is very hard to explain.