Hi #codeforces

I have solved around 100 (800 rating) questions and 20 (900 rating) but when i solve a another 900 rating question i first get in doubt by seeing the long theory of question. somehow i make a courage to read and understand but then i ended up with not able make correct solution. sometimes i think whole diffrent approach as compare to ideal.

for example I was solving this clockwork question (900 rating) . i even did not understand the question. but when i see the solution i see same if else , loops , vectors use . thatm means i know using what problem can be solve but how to arrange these pieces is seems impossible.

what should i do any suggestion.

i code in c++