My current goal is reaching 1400+ rating (top green or bottom cyan). I solved a quiet lot of problems and almost all bottom part of a2oj ladder 1300-1400 problems(50 harder). I realised that 50+% of my ideas are correct, and I often fails at string,bits and dp problems, and sometimes my solves are wrong. Also after holidays I haven't so much time to do cf. So I have some questions: 1) what the better way to develop( solving a2oj 1400-1500, solving 1300-1400 extra problems or solve problems on topics I usually fails. 2) how to test tasks when it's fails on 3-4 test. 3) what to do if I stack on some rating and I cannot solve problems with higher rating?

P.S. sorry for my poor English and I will be grateful for any advicе