I have been at red once when there were more formal problems(ex tree dp) at contests, but now I need more idea, ad-hoc, math, greedy. I tried to solve difficulty 2300~2500 and upsolved for years but cannot solve it well.

I know there is no such secret tip to be red, but I want to ask "Am I too stupid to solve those good idea problems? Or do I need more time? Or am I doing something wrong?"

I'm upsolving contests at 2017, but I feel a bit easier than these days even the difficulty is same.

Are the old problems easier?

I love solving problems, but I don't think I can hold it as a job. :( So, I am looking for similar things that I can do after graduating from university. I am thinking about studying discrete math, graph theory at graduate school, but are there more options?

Let array a1,...,an, ( 1<= n <= 10^6 )

3 kinds of quarries, m in total ( 1<= m <= 10^6 )

1 l r k: add k to al, ..., ar

2 l r k: change ai ( l<= i <=r ) in to max( ai , k )

3 l r: print max( al, ... ,ar )

I think it could be done it at mlogn by segment tree. How can I?

I feeled my rating and skill is stuck.

When I looked at my rating graph, I found it was just haning around about 2050 to 2150 average.

Every one says to be good, solve more problems, but I have solved almost every 2100~2400 (often 2500 and 2600) in div1,2 contests for last 1 year.

I think I am in some trouble. What can I do?

I found my rating always fall down if there are a lot of math(specially, number theory). Where can I find those problems about difficulty div2 D~E?

I'm solving problems of difficulty 2000~2300 at the problemset.

But a funny thing is, problems from div3 and edu is much more easier than from div1,2 for me. Even the difficulty was inverse.

Is it because the style of problems? Or the difficulty is not accurate?

My rating is usually about 2000~2100. I think I can get higher if I can solve difficulties 2200~2500 in contest and upsolved it for 10 month.

But it is still too hard for me to since it passed 10 months, and I'm just hanging around 2000~2100. What can I do? Is just upsolving is not a correct way?

Can someone recommend me some segment tree/range query problems like this? https://codeforces.net/contest/1136/problem/E