I can feel that I am making great progress now.. if inspected closely, it is obvious that what I‘m getting through is, a newbie phase: 

coding details mask actual logic underneath

It is interesting that it is very similar with situations when I first time coded C++, Haskell - at that time, I couldn‘t see what I was trying to do because of details-masked eyes. I thought it may be harder for algorithms, but after some time, it is the same. Good news. I think I‘m on the way to a better ACMer as how I became a good C++ programmer :)