It's really difficult to know because all the programming contest culture is C++, from what I can see. Someone who is experienced with programming contests is much more likely to do well than someone just trying something out for the first time for fun, and all those people use C++ because the programming contests mostly accept only a small handful of languages, of which C++ is the clear winner for performance.

I would expect this effect to utterly dominate any actual differences in languages right now. Comparing programming-contest-experts-in-C++ to newbies-with-$FAVORITE_LANGUAGE is not going to be a fair fight in something like this, where algorithms and insights dominate.

If TopCoder et al took the same suite of languages, and had for long enough that skills had equalized after the first mover network effects to whatever was really best for this sort of thing, we'd be able to make a better guess about what languages are good for what. (I would then conclude that I still don't really care because I'm not usually doing programming contests. But it would at least mean something, unlike the current results.)