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ucup 审题 rubric

2025-12-13 23:16:10 By Qingyu

这不是一个严肃的文档,是一个随机的随笔。

审题流程

第三届 Universal Cup 决赛的题目将由 The 3rd Universal Cup Finals Problem Selection Committee (题目选拔委员会,PSC) 选出。PSC 成员由 Universal Cup 科学委员会决定。

我们采用多轮审核机制。一道题目会首先被快速的初筛,而有竞争力的题目将会被更详细的审阅。我们采用多轮审阅的原因为:

  1. 投稿数量急剧增加,我们不可能快速审阅数百道题目
  2. 如果一道题目被太多人看过,那么被拒绝后,出题人很难投稿到其他比赛,造成很大的困扰。

第一轮,每道题目被随机分配到 2 个不同的 Reviewer。

  1. Read and Solve the problem 阅读题⽬,理解题⽬的含义。
  2. Come up with your own solutions. 花一定的时间,想一想你的直觉是什么?怎么解决这个问题?题目给人的第一印象是好的吗?
  3. Read the Editorial. 感受出题人的 intuition。出题人的题解是对的吗?符合直觉吗?趣味吗?

在你对题⽬的理解完成后,你需要给出你对这道题⽬的评分,分别为 Rating、Difficulty 与 Expertise,以及在 Response 中简短给出你对这道题⽬的评价。

最有竞争力的一批题目将会进入第二轮,被额外的 1~2 个 reviewer 审阅。

如果在两轮审阅后,题目非常有竞争力,题目选拔委员会将会在会议中讨论是否录取这道题目。每个最终被使用的题目都会被 PSC 所有成员看过,且得到科学委员会的审阅与监督。

Evaluate the tasks

Rating

Rating 分为 9 档,表⽰你对题⽬的评价。

  1. -1 - Desk Reject:我认为这道题⽬存在显著的问题,以至于其完全无法使⽤在比赛中。例如题⽬是错题或者存在完全⼀致的原题。任何满⾜基本要求的题⽬都不应被评为 -1 分。
  2. 1 - Strong Reject:我认为这道题⽬极度糟糕,无法提供任何价值。如果被选入了比赛,我会觉得完全无法接受。它虽然是⼀道正确的题⽬,但他出现在比赛中无法对比赛带来任何的价值,只会显著降低⼤家对比赛的印象。就算没有其他题,我也不觉得应该是⽤这道题⽬,还不如留下空位。
  3. 2 - Reject:我认为这道题⽬很糟糕。我不希望它被选入比赛,因为它没有提供应有的价值,解决这道题目只会浪费选手的时间。只有在没有其他可选项的时候,我才会认为选入这道题可以接受,但我也会对比赛造成很大的担忧。
  4. 3 - Weak Reject:我认为这道题⽬有点烂。要么相关的 idea 非常⽼套,在各种比赛中⼗分常见︔要么题⽬没有趣味性,让⼈感觉非常无聊。也有可能题⽬本身并不错,但在⼤局考虑下不适合被放入比赛。我倾向于不使⽤这道题,但这道题还是存在⼀定的价值,如果被⽤在了比赛,我会觉得有点糟糕,但还好。
  5. 4 - Borderline:我认为这道题⽬是个题。它不是很趣味,也可能它并不惹⼈喜欢。但它具有⼀定的道理,符合我对⼀场比赛应该有的题⽬的理解。我对这道题是否要⽤比较犹豫,但如果我是选⼿,看到这道题我会觉得挺正常,不会觉得很失望。
  6. 5 - Weak Accept:我认为这道题⽬还挺好。这道题有⼀定的趣味性,或者可以向比赛提供不错的价值(例如区分度/趣味性/平衡性)。我会倾向于使⽤这道题,但如果这道题被拒绝,我觉得也能理解。
  7. 6 - Accept:我认为这道题⽬不错,符合我对 ucup finals 好题的理解。这道题具有很不错的价值,是⼀道好题。我推荐使⽤这道题⽬,如果没有什么意外他不应该被拒绝。
  8. 7 - Strong Accept:我认为这道题⽬非常好,让我印象很深刻。就算在我做过的最好的比赛中,我也认为这道题⽬是不可多得的好题。它会为比赛提供非常珍贵的价值,出题⼈⼲的很漂亮。我不可想象这道题⽬会被拒绝,除非是极其特殊的原因。
  9. 9 - Best Problem Candidate:这是我今年看到的最好的题⽬。选⼿只要做出这道题⽬,就应该会被其所惊艳。这道题⽬在任何比赛都不可多得,我会为出题⼈喝彩。这道题⽬不被选入 UCup Finals,是 UCup Finals 的遗憾。

Difficulty

Difficulty 的评分与 QOJ 评分并不相同。

Difficulty 分为 8 档,表⽰你认为题⽬的难度。

  1. 1 - Very Easy:只要会写代码的⼈都能过这个题。这个题甚至不配被我称为签到题。可对应 QOJ 评分的 0 分。
  2. 2 - Easy:区域赛签到题。预期普通区域赛的⼏乎所有队伍最终都能通过这道题, ucupf 的所有参赛队伍都会在 15 分钟内通过这道题。可对应 QOJ 评分的 1~2 分。
  3. 3 - Medium-Easy:区域赛的铜牌题。可能存在⼀些 implementation or 思考的 stuck,但总之来说非常简单。如果放到 OI 比赛⾥,我会期望他是⼀个 NOIP T2 level 的题。 预期 ucupf 的所有参赛队伍在做这道题时不会花费超过 20 分钟的总时间。可对应 QOJ 评分的 3 分。
  4. 4 - Medium:区域赛的银牌题 ~ ⾦牌题。做起来没有那么平凡,但只要是个 NOI 银牌 / CF GM ⽔平的选⼿,应该都能在不太长的时间内做出来。也可能存在⼀定的实现难度/技 巧。如果放到 OI 比赛⾥,我会期望他是⼀个略低于 NOI T1 level 的题。预期 ucupf 的⼤多数参赛队伍在做这道题时不会花费超过 40 分钟的总时间,最顶尖的队伍不会超过 20 分钟的总时间。可能会存在⼀两⽀队伍最终没有通过这道题,但我会觉得他们发挥的很有问题。可对应 QOJ 评分的 4 分。
  5. 5 - Medium-Hard:区域赛⾦牌+/出线题。在普通的区域赛中,我会预计有 5~10 个左右的队伍通过。如果放到 OI 比赛⾥,我会期望他是⼀个介于 NOI T1 ~ NOI T2 level 的题。预期 ucupf 的⼤多数参赛队伍在做这道题时不会花费超过 60 分钟的总时间,最顶尖的队伍不会超过 30 分钟的总时间。可能会存在四五⽀队伍最终没有通过这道题,我觉得挺正常。可对应 QOJ 评分的 5~6 分。
  6. 6 - Hard:区域赛的夺冠题。在普通的区域赛中,我会预计有 0~2 个左右的队伍通过。如果放到 OI 比赛⾥,我会期望他是⼀个介于 NOI T2 ~ NOI T3 level 的题。预期 ucupf 会有⼀半的队伍做出来这道题。(对应 Semifinals Report 中的 Medium-Hard)。可对应 QOJ 评分的 6~7 分。
  7. 7 - Very Hard:在区域赛/ecf中出出来应该是光头题。在 NOI 出出来应该也是光头题。预期 ucupf 会有两三⽀队伍能做出来这道题,但应该没有队伍能做出来 2 道这个难度的题。可对应 QOJ 评分的 8 分。
  8. 8 - Impossible:预期不会有队伍通过。可对应 QOJ 评分的 9~10 分。

Expertise

Expertise 分为 5 档,表⽰你对题⽬的了解程度。

  1. 0 - No Familiarity:我完全看不透这个题。我不知道咋做,也不知道题解在说啥(或者没有题解)。题⽬可能很厉害,也可能很烂,但我完全不懂。
  2. 1 - Limited Familiarity:我看懂了这个题,⼤概知道题解在写啥了(或者没有题解),但我其实不是很了解这个题背后的 idea。这相关的题⽬(数据结构︖组合博弈︖图论︖计数︖)我也并不擅长,所以不好说。
  3. 2 - Some Familiarity:我明⽩这个题,理解这个题怎么做。也许有些细节我没想清楚,但不出意外就是这么做。这相关的 topic 我有所了解,但我也没有深刻到可以随意点评。
  4. 3 - Good Familiarity:我完全明⽩这个题咋做了,我可以给你讲讲。这个题⽬的⼀些development 我比较懂,也许我之前没想过类似的东西,但我现在完全理解了作者的想法。
  5. 4 - Great Familiarity:我懂完了!我完全精通这道题!

Final Evaluates

$$R = \frac{\sum R_i}{\sum 1}$$

$$\dot R = \frac{\sum E_i \cdot R_i}{\sum E_i}$$

New Feature: Forum in each Problem

2025-12-12 23:21:26 By Qingyu

We have updated the issue report feature for each problem. Every problem now has its own independent discussion thread, where you are welcome to post discussions, editorials, or any other related content in the problem forum. All posts are public, making it easier for everyone to find relevant discussions and reference materials.

discussion.png

We will also use the problem forum to share updates, as well as useful resources such as tutorials and write-ups. We hope you enjoy this new feature, and we look forward to hearing your thoughts and contributions there!

IOI 2026 China Team Selection: Current Scoreboard, Tasks & Prediction Game

2025-12-04 18:50:36 By Qingyu

Hi all,

The first stage of the IOI 2026 China Team Selection has just concluded. The top 50 48 participants from the 2025 National Olympiad in Informatics (NOI) will compete for a spot on the Chinese national team for IOI 2026.

The rule of selecting CHN team this year:

  • Homework (10%): also known as mutual tests, where the students were asked to prepare a task, and solve 120 problems on the QOJ training tasks list
  • First stage (CTT; 54%; Dec 2, 2025 — Dec 4, 2025): three contests in classic olympiad format, where each contest worthes 18% of the score. Top 30 participants will advance to the final stage.
  • Final stage (CTS; 36%; Feb 6, 2026 — Feb 13, 2026): two contests in classic olympiad format, where each contest worthes 18% of the score.

The detailed selection rule is available here (in Chinese). After all the selections, top 6 students will be qualified to the interview & thesis defense stage, and four of them will be selected to represent China in IOI 2026.

The current scoreboard can be found here. Thanks to Crysfly for compiling this document.

Past problems of the China IOI Team Selections can be found here (first stage and final stage), and this year's task is available here. You are welcomed to try these tasks or pratice them, but we will not hold an open mirror for these contests.

CTS 2026 Prediction Game

As our usual fun tradition, we will host The CTS 2026 Prediction Game at our Voting Game Site.

You need to predict the 1st to 6th place winners. Each contestant can only be nominated once.

  1. For each contestant you nominate who finishes in the top 4, let $R$ be the actual rank of the contestant and $r$ be the rank you predicted ($1 \le r \le 4$):
    • You receive $10$ points $1 \le R \le 4$, and a bonus $3$ points if $R = r$
    • You receive $5$ points $5 \le R \le 6$
    • You receive $2$ points $7 \le R \le 10$
  2. For each contestant you nominate who finishes in ranked 5 or 6, let $R$ be the actual rank of the contestant and $r$ be the rank you predicted ($5 \le r \le 6$):
    • You receive $4$ points $1 \le R \le 4$
    • You receive $8$ points $5 \le R \le 6$, and a bonus $3$ points if $R = r$
    • You receive $3$ points $7 \le R \le 10$
  3. If you leave a rank blank (i.e., choose not to make a prediction for that rank), you receive 1 point for that empty slot.
  4. There is a bonus question asking if anyone ranked 5 or 6 will enter the national team.

The 3rd Universal Cup Finals: How to submit your tasks

2025-11-21 04:43:30 By Qingyu

Interested in submitting your tasks? Great! We sincerely thank your contribution to the Universal Cup!

Before submitting, you need to have an account on QOJ and properly protect your password. You should submit all your proposals at https://qoj.ac/proposals. All your task materials will be uploaded using your account, and you will receive notifications and feedback from us within the system only.

The submission deadlines

We have three submission cycles this year. Although we do not place any disadvantages on late proposals, we strongly recommend you submit your tasks as early as possible so we can provide a more detailed review of each of your task proposals.

Stage Submission Deadline Decision Notification
1 December 15, 2025 January, 2026
2 February 1, 2026 March, 2026
3 March 1, 2026 April, 2026

The final deadline to submit your tasks is March 1, 2026. Late submissions might not be reviewed.

Things need to be prepared

After clicking the "New Proposal" button, you will receive a dedicated submission page for your proposal only. If you need to submit multiple tasks, you must create multiple proposals independently.

In the proposal management page, you need to upload your problem statements, a brief editorial, and a list of conflicts. Each text box provides you with a simple Markdown editor (so you can use $\binom{n}{m}$ or **two** to format your task content). All materials you submitted must be written in either English or Chinese.

Problem Statement

The problem statement should contain the core idea of your task proposal. You do not need to come up with a funny background or detailed definitions. You may submit a formal camera-ready statement if available, but it is fine to just write a few sentences to describe what you would like to ask in this task. Be sure to include constraints in the problem statements — it is fine to just have an approximation; you can change them when preparing your tasks if accepted.

Other sections like input format or example explanations are not required, but you may add them if you find they are helpful for the reviewers to understand your task.

Brief Editorial

A brief editorial is a required component of your task submission. The brief editorial should describe the intended solution to your task, and you may include any alternative or suboptimal solutions in your editorial.

The editorial is used to help the reviewers better understand your proposal. Reviewers are all experienced competitive programmers, so you may utilize any well-known tricks without detailed explanation. You do not need to write every proof of the lemmas you used, but you should keep your editorial informative to the reader.

It is fine if you are not sure your approach will be optimal for this problem. When reviewing your proposals, our reviewers will first come up with their own solutions, and multiple reviewers will work with admitted tasks to see if any improvements could be made for the task.

Furthermore, if your idea comes from a paper or other tasks, you should also list them in the editorial section. You may also list any additional comments in the editorial section.

List of conflicts

Security is the top concern we have in our selection process. You have to list anyone, including non U-Cup contestants, who knows any parts of your task proposals. BE SURE TO MAKE YOUR CONFLICT LISTS COMPLETE BEFORE SUBMITTING YOUR TASKS.

We understand that your tasks might have been proposed to other competitions, and this is common in the competitive programming community. You are required to report all the trainings/contests/competitions you have submitted your tasks to, no matter online or offline, school trainings or international championship.

You should also list all the platforms you used to store or create your tasks, such as GitHub, Polygon, Libre OJ private tasks, Google Docs, etc. This will help us to know the context of your task proposal and evaluate the security of your task proposals.

You have to list everything on your best effort. If you are not sure about any conflicts, just list them. Listing more conflicts will not negatively affect your proposal.

The evaluation process

After finishing all parts of your proposal, you need to make sure that you have switched the status of your proposal to "ready for review". Once you marked ready, we will hide the task content to everyone from the proposal page, so that we could reduce the risk of leaking a proposed task. As such, you will be unable to make any changes to that proposal after clicking ready. If you do need to make any changes after submitting your proposal, you need to send an email to [email protected] with details of your proposals.

Following this, our task reviewing team will begin working with your proposal. Your proposal will only be visible to our task reviewing team and dedicated reviewers. If your proposal is not accepted, we will inform you the list of the people who has reviewed your task, and you may submit any unaccepted proposals to any other competitions.

Our task reviewing team includes:

  • Qingyu Shi
  • Lingyu Jiang
  • Yuhao Du
  • Yaohui Zeng
  • Yichen Li
  • Yaowei Lyu

Q&As

Q: What types of tasks are you accepting?

A: We accept a wide range of task types. We do not have a strict syllabus for our competition, and you may submit tasks on all kinds of topics. Besides classical batch tasks, you can also submit interactive tasks, communication tasks, output-only tasks, or any other innovative task types! Our Technical Committee will coordinate with the Scientific Committee to ensure your task can be properly judged.

Q: Do you accept easier tasks?

A: Sure! In fact, we especially struggled with deciding on the easier part of the problem set when doing previous problem-settings. Creating a great easy task is hard, and we definitely want to hear your ideas.

Q: How many tasks may I submit?

A: There is no limit on the number of tasks you can submit, and we do not have a quota on the number of tasks to be used by a single author. In fact, we once had a single author propose dozens of tasks, and five of them were ultimately admitted.

Q: Do you have any preferences on task styles or topics?

A: No. We have no preferences or quotas on any specific topics. We might propose zero or even four geometry tasks, all depending on the context of the whole contest pool. However, our primary goal for the contest is to create a diverse tasks pool and a balanced problem set with appropriate amounts of thinking and implementation. Some topics, like data structures and combinatorial counting, receive far more proposal submissions than others, making the selection process for these topics extremely competitive. We encourage you to try a more innovative field, and we especially value tasks with deep insight and creativity over advanced knowledge.

Q: What is the definition of "advanced knowledge"? Can I propose a task involving advanced algebra? What about implementing an algorithm mentioned in some FOCS paper?

Q: Again, we do not have a strict syllabus or constraints in our problem-setting process, and everything will be evaluated holistically based on your task approach and the context of the whole contest pool. In our tasks selection process, insight and creativity are the most important factors. A task relying purely on advanced knowledge with no underlying insights might not fit our contest goals. If you decide to propose a task using uncommon competitive programming tricks or advanced techniques, it is best to include more intuitive thoughts or ideas that go beyond the core techniques themselves.

Q: Do you have any examples of good tasks you are looking for?

A: We accept all kinds of tasks. We are not a single-thematic or purely ad-hoc contest, so we cannot really give a definition on what is a good task. Even if you feel your task is not great, it might still be accepted if it fits the needs of our pool. Therefore, submit your task if you are interested.

Q: I want to be an onsite judge. Can I have a spot if my tasks were accepted?

A: We sincerely welcome anyone who wishes to join our judges team. You can apply to be an onsite judge after the problem selection process, and the details will be confirmed after our tasks selection process.

Q: I have more questions...

Q: You can contact me via [email protected].

The 3rd Universal Cup Finals: Call for tasks

2025-11-21 03:33:29 By Qingyu

On behalf of the Universal Cup, I am pleased to announce the Call for Tasks for The 3rd Universal Cup Finals.

The 3rd Universal Cup Finals serves as the final championship of our third season, where the top-performing teams from the online stages and semifinals will compete for the prestigious title of Champion of the 3rd Universal Cup.

We anticipate selecting 10-15 high-quality tasks to create a contest experience comparable to the 2nd Universal Cup Finals. Previous Universal Cup Semifinals/Finals competition tasks can provide a good guide on the desired composition of tasks. You may check them here, here, and most recently here.

We sincerely welcome everyone who is not competing in the Finals to submit their tasks. This is a unique opportunity to share your problems with the strongest competitors in the community. Furthermore, selected task writers may have the chance to serve as an onsite judge at The 3rd Universal Cup Finals.

To submit your task, you must create a proposal and upload all task materials directly to our proposal management system: https://qoj.ac/proposals. This is the only valid method for task submissions. Please do NOT submit your tasks via emails, Discord messages, private messages, or any other channel. A detailed submission guide is given here.

We look forward to seeing your tasks contribute to The 3rd Universal Cup Finals!

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