[prezjordan]

I have a suspicion that they have solved thousands upon thousands of these problems, developing a library of sorts. They can probably translate these problems into ones they have solutions for and just work from there.

Maybe that's jealousy talking, though.

[droque]

I think it is a feat to practice to the point of having seen thousands of problems and still know (or have a felling of) the way to go.

(Actually, most of the good sport coders that I know develop that knack of knowing where the solution is headed, without pinpointing a previous problem)