matthew99's blog

By matthew99, history, 3 months ago, In English,

UPDATE: China team leader Hong Wang's introduction of these contests can be found here.

If you were a Chinese high school student, what would you need to do to become a member of IOI China Team?

As you know, China is a hugely populated country, and we have our own special system of contests.

The following is only a brief introduction to our system. Details information in Chinese can be found here.

NOIP(联赛)

NOIP, namely National Olympiad of Informatics in Provinces, is an annual nationwide contest that nearly everybody can participate in. As the name suggests, it's held in provinces---in each province there's a site where this contest is held.

Provincial Selection Contests(省选)

This contest is held annually in every province. Members of the Provincial Teams(省队) are selected based on their performances on this contest combined with those on NOIP.

NOI(SC)(全国赛)

NOI(SC), or CNOI, namely (Chinese) National Olympiad of Informatics (Summer Camp), is an annual nationwide contest held in different cities every year. 50 members of the National Training Team(国家集训队) are selected based solely on their performances on this contest. Moreover, every member of this team receives the chance to get admitted(保送) by top universities in China.

Tsinghua University Training(清华集训)

Every winter, all members in the NTT are gathered in Tsinghua University(清华大学, abbr. THU) to have a 4-day long competition, which is called Tsinghua University Training.

(NOI)WC(冬令营)

(NOI)WC, namely (National Olympiad of Informatics) Winter Camp, in an annually contest where 15 candidates for the Chinese National Team(国家集训队候选队员) are selected based on their performances on this contest combined with those on THU training and their scores on assignments. WC is usually held in the same place where NOI was held the same year.

CTSC(中国国家队选拔赛)

CTSC, namely China Team Selection Contest, is, as its name suggests, a contest where 4 members of Chinese National Team are selected based on their performances on this contest combined with their scores on THU training, WC and all kinds of assignments. Although 6 top-scorers have the chance to enter the final Interview with a speech in English and several Q&A in Chinese, most of the time 4 top-scorers are selected regardless of their performances in the interview. CTSC is always held somewhere in Beijing.

So, that's all you would have to do:

Travel to the capital of your province and do NOIP

Travel to the capital of your province and do the provincial selection contest in your province

If you are lucky enough to enter the provincial team, travel to a new city and do NOI

If you are lucky enough to enter the NTT, travel to Beijing and do THU training and in the meantime do all the assignments

Travel to a new city and do WC

If you are lucky enough to be a candidate, travel to Beijing and do CTSC.

All these processes together take more than a year. So if you want to participate in IOI2017, start your NOIP in 2015.

Finally, if you enjoy reading it, don't forget to click the like button.

 
 
 
 
  • Vote: I like it  
  • +538
  • Vote: I do not like it  

»
3 months ago, # |
  Vote: I like it +33 Vote: I do not like it

Thanks, interesting information. What is the purpose of the English interview? Do you have other training camps for IOI participants and how long are they?

  • »
    »
    3 months ago, # ^ |
      Vote: I like it +30 Vote: I do not like it

    I think the raison d'être of the interview should be to avoid some contestants that are very good at programming but extremely bad at other things such as English.

    All important camps are listed in this post.

  • »
    »
    3 months ago, # ^ |
      Vote: I like it +69 Vote: I do not like it

    The story that I heard is that it started as a `psychological screening' process in 2004 after some contestant didn't submit codes that were worth 270 points on day 2 of IOI 2003.

    • »
      »
      »
      3 months ago, # ^ |
        Vote: I like it +62 Vote: I do not like it

      Could you please elaborate on the contestant that didn't submit their Day2 submissions?

      If he's Qiming Hou(0, 0, 0 on Day2), that would make him the absolute winner by a huge margin(70 points).

      Did he get discriminated or something?

»
3 months ago, # |
  Vote: I like it +28 Vote: I do not like it

Can we find english version of problems?

»
3 months ago, # |
  Vote: I like it +15 Vote: I do not like it

How important are THU training, WC and assignments compared to CTSC in the Chinese National Team selection? Since both you and jcvb missed IOI once after failing "a relatively easy problem" I suppose is extremely important to perform good in CTSC and the other things work as tie-breaker.

  • »
    »
    3 months ago, # ^ |
      Vote: I like it +39 Vote: I do not like it

    THU training 15%

    WC 10%

    Assignments 25%

    CTSC 2 days 50%

    jcvb did fail a relatively easy problem. As he was #1 before the last day of CTSC

    I failed because I was not skillful enough. I was never in the top 4 whatever stage of the contest.

»
3 months ago, # |
  Vote: I like it +10 Vote: I do not like it

I remember a post saying that a very strong contests didn't made it to the Chinese National Team because he failed in a physics question. When you mention 'all kinds of assignments', do they use questions outside of the Mathematics/Computer-Science realm ?

  • »
    »
    3 months ago, # ^ |
      Vote: I like it +20 Vote: I do not like it

    Sometimes. This year there's even a task that's about squeezing your code. Should this task appear in CTSC, there would be other strong contestants that wouldn't make it to CNT.

    • »
      »
      »
      3 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Don't these tests (Physics / English / "How to Squeeze your Code") somewhat randomize the selection process? How has the score distribution been like for CTSC, in the past years? Do people get full scores? If the scores that the top contestants achieve on the actual tests are similar, then it boils down to a matter of luck, doesn't it?

      • »
        »
        »
        »
        3 months ago, # ^ |
        Rev. 2   Vote: I like it +34 Vote: I do not like it

        You can say that again. Luck is indeed important in these contests. Let me just explain why.

        The most staggering feature in CTSC, as well as other Chinese contests, is that you don't have to get full score on any task to be a member of the National Team. As you have no feedback during the contest, not even whether your code can pass the compilation, it's a luxury to get all your partial solutions correct. People who have more solutions fail, fail. Oftentimes, get all simple subtasks correct---even if they sum up only a few points, and you'll enter the National Team. In NOI last year, the subtask worthing 95 points in one task is much easier than the other 5 points, many participants fail because they focus on these 5 points and end up having not enough time on the other two tasks. Moreover, IPSC styled answer-submitting tasks prevail, on which generally you spend more time, the more points you'll gain.

        Ostensibly, tactics are much important that what you are, especially in contests with answer-submitting tasks, as you have to find a balanced way to split your time between these tasks and other ones.

        However, people aren't born experts on choosing tactics. Many people fail on choosing them and in retrospect, their choice seemed reasonable. So finally, luck is king. Skillful people fail commonly, and less skillful people come to replace them.

        • »
          »
          »
          »
          »
          3 months ago, # ^ |
            Vote: I like it +25 Vote: I do not like it

          Few years ago in Vietnam, we also had no feedback during the contest for IOI team selection. But 1 professor finally decided to fight against it, many people agreed, and now we have online feedback contest (only for team selection contest, as there are not so many students in this contest).

          Maybe someone in your country can do the same?

          • »
            »
            »
            »
            »
            »
            3 months ago, # ^ |
              Vote: I like it +5 Vote: I do not like it

            Well...contest holders are afraid of cheating. Contests with feedbacks may promote cheating. So until now there is still no contest with feedbacks. But we sometimes have strong samples.

          • »
            »
            »
            »
            »
            »
            3 months ago, # ^ |
              Vote: I like it +33 Vote: I do not like it

            My experience with ChnNOI and CTSC data (from solving them and using them for US selections) is that under feedback, the optimum strategy more or less becomes submitting unintended pruned solutions / heuristics to break the data. This is due to the combination of the extremely hard problems and data written in the last minute. My impression from 5~6 years ago is that many of the problem setters are undergraduate students who are very busy with course work and etc, so there there is little beta testing (2 agreeing solutions if lucky), and only 1~2 types of generators.

            • »
              »
              »
              »
              »
              »
              »
              3 months ago, # ^ |
              Rev. 3   Vote: I like it 0 Vote: I do not like it

              Even if this is the reason, it seems reasonable to allow let's say 4-5 submissions per problem (followed by a final evaluation post contest). This should be enough to ensure that test data can't be hacked. With no feedback, I assume contestants might be spending time verifying their code against brute force solutions and creating test data themselves, instead of solving problems.

  • »
    »
    3 months ago, # ^ |
      Vote: I like it +25 Vote: I do not like it

    I think there was also someone who was rejected at the interview stage, but during the next 10 months, won TCSH and TCO, and was part of a team that won WF.

    • »
      »
      »
      3 months ago, # ^ |
        Vote: I like it +1 Vote: I do not like it

      Didn't know about this one, but it's surely a great slap in the face of the organizers. I can understand an English test, but asking questions non related to Competitive Programming doesn't make any sense.

»
3 months ago, # |
  Vote: I like it 0 Vote: I do not like it

It seems all the camps you mentioned are just on-site competition with accommodation. Is there any training for contestants? Or are they intersparsed with the contests?

  • »
    »
    3 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Yes. They count as part of the assignments.

    • »
      »
      »
      3 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Aha, so its like participants take training classes of their fellow participants?

      • »
        »
        »
        »
        3 months ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        You are almost correct. Moreover, all tasks in the competitions are from seniors.

»
3 months ago, # |
  Vote: I like it 0 Vote: I do not like it

WC is usually held in the same place where NOI was held the previous year.

Perhaps this should be "the same year"? WC is also getting organizers fully prepared for that year's NOI in summer.

»
3 months ago, # |
  Vote: I like it 0 Vote: I do not like it

Can we find English version of the interview questions?

By the way, travel expenses for all these students should be very huge. Do they have to pay themselves?

  • »
    »
    2 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    There is no official record of interview questions, even in Chinese.

    Travel expenses are waived for team members, but not for other participants.

»
2 months ago, # |
Rev. 3   Vote: I like it +5 Vote: I do not like it

Seriously, which is harder, to get on china IOI team or get gold medal on IOI?

  • »
    »
    2 months ago, # ^ |
      Vote: I like it -10 Vote: I do not like it

    It depends.

    For example, some people are experts at all Chinese contests but bad at other contests, so for them the later is harder, while most people think the former is harder.

    But let ratio speak, getting IOI gold medal is a ratio of 25 to hundreds, while entering the team is a ratio of 4 to all the thorsands of participants. Were everything a lottery, the former definitely would be much eaiser.

»
2 months ago, # |
  Vote: I like it 0 Vote: I do not like it

> and their scores on assignments

What kind of assignments is that?

  • »
    »
    2 months ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    Last year it was to upsolve a little more than 50 SRM rounds. Also, translate the statements and write solutions for one round(as there are 50 team members and a few middle school students so they added up to be a little more than 50 rouns).

»
2 months ago, # |
  Vote: I like it +10 Vote: I do not like it

I noticed that the Chinese Asia Pacific Informatics Olympiad contestants for 2016 are completely different from the IOI contestants. Is there any reason for that? Source: APIO results IOI china team results

  • »
    »
    3 weeks ago, # ^ |
    Rev. 2   Vote: I like it +5 Vote: I do not like it

    It's a rule set by CCF that you cannot officially take part in APIO if you enter the NTT.I think the purpose is to give opportunity to more students.

»
7 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

Auto comment: topic has been updated by matthew99 (previous revision, new revision, compare).

»
3 weeks ago, # |
Rev. 2   Vote: I like it +10 Vote: I do not like it

Thanks for this amazing introduction, very useful information for one who likes OI after graduation from university(like me). Congratulations for being a member of China team in IOI.

»
2 weeks ago, # |
  Vote: I like it +5 Vote: I do not like it

Auto comment: topic has been updated by matthew99 (previous revision, new revision, compare).