Buying account would be the fastest option (:

Auto comment: topic has been updated by sarthak_tirpude (previous revision, new revision, compare).

Im pupil but i mostly try to solve more than 1600 and i suggest you to improve your dp and seg tree and the most important one speed

My expert roommate suggested that I should practice solving problems around rating 1600-1800, have been doing so for a while. It's been only a week or two but think I have improved a lot since then. Although not yet enough to reach expert

You just reached cyan, lol.

Just keep doing what you did to get there, it will probably work.

As a person who just reached expert. The answer is simple just solve problems.

reaching expert through Div 3 is relatively easy(i became expert after last Div3 round).

But you just have to focus on doing problems of rating 1600-1800. What I personally did was picked a rating and started doing problems. And shifted to the next rating when I felt I was comfortable enough.

As an expert,

I would say work on your speed and try solving Div2 ABCs in under 30mins or solve till D.

Ask practice.

solving exactly 69 problems does the trick

To reach expert you either have to be able to consistently solve A-C in Div2/Edu quickly, or solve A-D in Div2/Edu round.

imo it's easier to build up speed on easier problems before trying to solve harder problems, so what you can do is virtual participation in div 3 contests and practice solving A-E as fast as possible. Div 3 problems D or E is usually around same difficulty as Div 2 problem C, so if you can get through A-E in about an hour, you should be fast enough to reach expert. There are also usually 2-3 problems in Div 3 contests that are significantly harder than the rest of the contest; practice on those as well since solving D in div 2 is also enough to reach expert. You can also practice random problems in the problemset; rating range to practice is about 1200-1500 if you want to improve solving speed, and 1500-1800 if you want to learn new concepts. If you use this method then make sure problem tags are hidden to simulate an actual contest as closely as possible.

As for specific topics knowing how to use greedy method is still important, especially knowing when it doesn't work. A lot of my issues with climbing into Expert came from trying to use greedy method on a problem when much easier methods were available. dp sometimes shows up in Div 2 C/D; one thing I notice is that it is much more likely to be the answer when the problem only requires a O(n^2) solution (usually when the constraints are like n <= 5000). Lastly combinatorics will be extremely useful at this range; make sure you know how to calculate stuff like n choose k mod r.

Mostly the difference between specialist and expert is speed; both groups can solve A-C in div 2, but expert just does it faster and with fewer wrong submissions.