Блог пользователя AshrafSustS19

Автор AshrafSustS19, история, 22 месяца назад, По-английски

I want to practice solving 2200-2400 rating problems, and I want to rely on guides as less as possible. But every time I am stuck on one problem, I have to worry about whether I am missing an observation or I just need to learn a new topic to solve this problem. I want to know and learn the topics and problem solving techniques that are common in problems of this range, so that the chances of me missing a topic when trying to solve a problem is as low as possible. What are the common topics that I need to learn

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22 месяца назад, # |
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I created a script to get tags from problems in the range [2100-2400]. Here is the output
Tag — Number of problems with this tag

result
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    22 месяца назад, # ^ |
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    May I use that script?

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      22 месяца назад, # ^ |
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      Sure!

      Code
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22 месяца назад, # |
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A bit offtop, but haven't you considered to start from problems in your rating range?

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    22 месяца назад, # ^ |
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    I'm not him, but he may consider his rating range problems too boring (even though he is not consistent at them) and so he decided to master his rating range by knowning how to solve a lot harder problems.

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    22 месяца назад, # ^ |
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    So far, I have around 60+ 1800R, 50+ 1900R, 25+ 2000R problems. As for my regular practice, right now I would be focusing on 2000R problems. But I also want to try some high rated problems from time to time to keep things interesting

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      22 месяца назад, # ^ |
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      yes but if you can solve 1800R~2000R problems by yourselve, won't your rating be 1800~2000 right now? (thinking)

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22 месяца назад, # |
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Although this is good for you, if you can solve the problem with difficulty of 1900 steadily, you will not only have the level of specialist. So I still advise you not to be too anxious.

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22 месяца назад, # |
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most probably you need to learn data structures like BST,heaps also graph matchings,segment tree, minimum spanning tree algorithm(Prim's and Kruskal's) fenwick tree,shortest paths and many more

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    22 месяца назад, # ^ |
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    I know almost all of these topics. You will actually find a lot of problems related to these topics in 1800-2000. What I am looking for are the more advanced algorithms and data structures I may need to learn. For example, Square root decomposition, centroid decomposition, heavy light decomposition etc. I came across a few problems that require these, don't know how common they are though

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      22 месяца назад, # ^ |
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      try Brute force,DP,DFS,BFS,Dijkstra,Binary Indexed Tree,nCr, nPr,Mod inverse,Mod inverse,Binary Search,Bitmasks

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22 месяца назад, # |
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binary search.

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22 месяца назад, # |
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It is more important to train your intuition than to learn random algorithms because most problems tend to require you to make observations. I am still bad at making observations for problems in the rating range you described, so at the moment I am going through atcoder problems rated between 2000~2400. Also, you should probably look into USACO guide. Knowing most of the sections in Gold, Platinum, and advanced division category should be more than enough to solve any problem rated around 2100~2400, and way beyond.