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chen_zhe's blog

By chen_zhe, history, 5 months ago, In English

This article relies on ChatGPT-4 for translation.

China has been hosting the National Olympiad in Informatics (NOI) since 1984. Over the past forty years, it has developed a unique system. I intend to provide a brief introduction to this system for everyone.

In mainland China, about 100,000 people prepare for informatics competitions each year. The first step in these competitions is to participate in the CCF Certified Software Professional Junior/Senior (CSP-J/S). CSP-J is for contestants aged 8-14, while CSP-S is for contestants aged 10-18.

CSP-J/S is divided into two stages. The first stage tests general and practical computer science knowledge, such as base conversion, principles of linked lists, and reading programs to answer questions. About 40,000 to 50,000 people pass the first stage of CSP-J/S. The second stage of CSP-J/S focuses on programming. The CSP-J second stage exam lasts 3.5 hours, while the CSP-S second stage exam lasts 4 hours, each with 4 problems. Approximately 20% of the contestants in each province can receive a first prize.

The second step is to participate in the National Olympiad in Informatics in Provinces (NOIP). This competition is only for middle and high school students who have achieved certain results in the second stage of CSP-S. NOIP is similar to the second stage of CSP-S, with a 4.5-hour exam, 4 problems. In NOIP, the top 20% of contestants in each province can receive a first prize.

The third step is the provincial team selection. This competition is only for contestants who have won a first prize in NOIP. Each province selects the top 10 contestants (more precisely, the top 5-17 contestants, depending on the province's quota) from the NOIP first prize winners (50-200 people, depending on the province's competition scale) to participate in the National Olympiad in Informatics.

The fourth step is to participate in the National Olympiad in Informatics. About 300 contestants from across the country participate as official contestants through the provincial teams. The exam lasts two days, with 3 problems each day, and a time limit of 5 hours per day. The top 50 contestants receive gold medals, the 51st to around the 200th contestants receive silver medals, and the rest above top 85% receive bronze medals. The gold medalists form the national training team for special training.

Common websites used by Chinese informatics contestants include Luogu. During holidays, this website sees tens of thousands of active users practicing problems daily. Before CSP-J/S, Luogu's daily submission volume can reach 150,000-250,000. A brief introduction to using Luogu. Based on China's competition system, Luogu classifies problems into the following levels:

【入门难度】(Introductory Level)Suitable for beginners, below or equivalent to Codeforces 800 difficulty.

【普及-】(CSP-J minus)Simple CSP-J problems, equivalent to Codeforces 800~1200 difficulty.

【普及/提高-】(CSP-J/CSP-S minus)Intermediate CSP-J problems, solving these in the competition can earn a first prize, also the difficulty of simple CSP-S problems, equivalent to Codeforces 1200~1600 difficulty.

【普及+/提高】(CSP-J plus/CSP-S/NOIP)Simple to medium difficulty CSP-S and NOIP problems (as difficulty fluctuates in different years), equivalent to Codeforces 1600~2000 difficulty. Solving these problems often results in a first prize in CSP-S or NOIP.

【提高+/省选-】(CSP-S plus/Provincial Team Selection minus)Medium to hard CSP-S and NOIP problems, equivalent to Codeforces 2000~2500 difficulty.

【省选/NOI-】(Provincial Team Selection/NOI minus)Difficult NOIP problems, or simple to medium provincial team selection problems, equivalent to Codeforces 2500~3000. In most provincial team selections, solving these problems gives a good chance of making the provincial team.

【NOI/NOI+/CTSC】(NOI difficulty)Medium to difficult NOI problems, equivalent to Codeforces 3000~3500, or even more difficult. Solving these problems in NOI gives a high probability of winning a gold medal.

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5 months ago, # |
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Auto comment: topic has been updated by chen_zhe (previous revision, new revision, compare).

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5 months ago, # |
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Fun fact: being an LGM on Codeforces doesn't mean one can pass the provincial team selection for sure.

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    5 months ago, # ^ |
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    Fun fact 2: being an LGM on Codeforces doesn't mean one can got silver or above medals in APIO for sure.

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      3 months ago, # ^ |
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      Fun fact 3: being an LGM on Codeforces doesn't mean one can got bronze or above medals in WC for sure.

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    2 months ago, # ^ |
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    Fun Fact 4:the No.1 of NOI isn't LGM。

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      4 weeks ago, # ^ |
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      who is he

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      4 weeks ago, # ^ |
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      Fun Fact 5: Becoming an LGM on Codeforces only guarantees a full score on NOIP, but it does not guarantee that you'll earn points in the provincial team selection.

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5 months ago, # |
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The top 50 contestants receive gold medals, the 51st to around the 200th contestants receive silver medals, and the rest receive bronze medals.

In fact, the bottom 15% receive no medal.

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5 months ago, # |
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Auto comment: topic has been updated by chen_zhe (previous revision, new revision, compare).

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5 months ago, # |
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According to some sources, Luogu is preparing for it's internationalization, Meow. One hopes to see an international oriented Luogu like CF in the future, Meow.

China's NOI is becoming harder and harder, Meow. One hopes CNOI can have a closer connection with the in class academic performance of Chinese students in the future, Meow.

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5 months ago, # |
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Actually, for Olympiad in Informatics, in most parts of China (such as Shandong Province, China), there are not many preferential policies for high school and university admission.

The interesting fact is that there are a large number of training institutions in China that are teaching competitive programming. Most of the students in middle schools have learned programming, but only a few can enter the provincial team.

About 60% of the boys in my junior high class have learned programming (:

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5 months ago, # |
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In case you don't know
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5 months ago, # |
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First off, nice blog!

I have read a comment somewhere mentioning "OI level" (probably related to the Luogu website). Can you tell what are these levels? Also how are these related to the Chinese OI system and how one can achieve them?

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    5 months ago, # ^ |
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    If you mean this comment, then the "OI Level" term stands for a scoring(?) system developed by CCF (which is the organization in charge of China's NOI). Luogu has a slightly different variation of this system but does not differ much. It mainly depends on a participant's performance in NOI, Winter Camp, APIO, or other preliminary contests for NOI.

    Approximate correspondence: Level 8/9/10 = NOI Medalist (Bronze/Silver/Gold). For Levels below 8 you can refer to this post by CCF.

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    5 months ago, # ^ |
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    The China Computer Federation (CCF) conducts a Computer Programming Competency Assessment for high school students, which might be what you refer to as the OI level. On Luogu, scores for levels 3 to 10 are supported. Levels 3, 4, and 5 are represented by a green hook, levels 6 and 7 by a blue hook, and levels 8, 9, and 10 by a gold hook.

    • Level 3: The contestant has won an award in CSP-J/S.
    • Level 4: The contestant ranks in the top 50% nationwide in CSP-J/S or NOIP.
    • Level 5: The contestant ranks in the top 20% nationwide in CSP-J.
    • Level 6: The contestant ranks in the top 20% nationwide in CSP-S/NOIP.
    • Level 7: The contestant ranks in the top 10% nationwide in CSP-S/NOIP.
    • Level 8: The contestant has won a bronze medal in NOI or accumulated 250 points.
    • Level 9: The contestant has won a silver medal in NOI or accumulated 500 points.
    • Level 10: The contestant has won a gold medal in NOI or accumulated 1000 points.

    Accumulated points consider participation in the NOI Winter Camp and APIO, with a complex calculation method. The maximum points for the NOI Winter Camp is 600 (awarded to the top scorer) and the minimum is 50 (awarded to the lowest scoring award recipient). Intermediate scores are distributed in an arithmetic progression. The maximum points for APIO is 500, with a minimum of 50. Generally, an APIO silver medal equates to 250 accumulated points. Only the highest points from each competition type are counted.

    Typically, we consider contestants at levels 3 to 5 to have a foundational knowledge of programming and algorithms. Contestants at levels 6 and 7 have considerable experience in algorithm competitions and can learn and apply algorithms to solve problems (equivalent to Codeforces' Expert or Candidate Master rating). Contestants at levels 8 to 10 are highly experienced algorithm competitors (equivalent to Codeforces' Master rating or above).

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      5 months ago, # ^ |
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      hook->tick

      Also although this standard is published by CCF, it's abandoned by itself.

      We(luogu) just found it good and use it to measure users' performance in official competitions.

      Years has passed and now there are really a large amount of ppl with blue tick or golden tick.

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5 months ago, # |
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I reported that chen_zhe violated the Luogu community rules (publishing the share generated by Chat GPT).

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    4 months ago, # ^ |
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    But here is Codeforces, not Luogu.

    And I think chen_zhe put Chinese articles into ChatGPT for translation, rather than using AI to generate articles.

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4 months ago, # |
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CSP-J is for contestants aged 8-14, while CSP-S is for contestants aged 10-18.

In fact,anyone can participate in a formal CSP test.For example,some students of grade 9 take CSP-J.

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    4 months ago, # ^ |
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    In fact, only primary or middle school students are allowed to participated in CSP-J/S in most provinces.

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      However,Wang Chuqi(kkksc03)participated in CSP-J/S 2019.

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        3 months ago, # ^ |
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        To register for CSP-J/S can be done either as an individual or as a school (below high school level).

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    2 months ago, # ^ |
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    For another example,some teachers also take part in CSP-J/S.

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3 months ago, # |
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It seems users who write comments under this article are almost Chinese

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4 days ago, # |
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Solving these problems often results in a first prize in CSP-S or NOIP.

In some province,it may need solve a blue problem.