We will hold UOJ Round #29 contest! The contest contains $$$3$$$ problems to be solved in $$$4$$$ hours.

King Volt of the Fleas decided to establish a brand-new academic discussion community called "Flea Universe". However, during the process of building the community, Volt encountered some technical difficulties. Can you help Volt overcome these difficulties and contribute to creating a new academic discussion community for the Flea Kingdom?

• Contest link: https://uoj.ac/contest/94
• Start Time: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20250216T1800&p1=33&ah=4
• Writers: Gellyfish, orzdevinwang, dXqwq, xyf007
• Testers: yaoxi, registeretsiger
• Duration: 4 hours
• Difficulty: like CF Div.1 contests (maybe slightly harder)
• The point values: 100-100-100

The contest will follow the Pretest rules: During contest, every submission will only be judged on the pretests (in the problem attachments). All submissions will be rejudged on the final tests after contest. All the problems will have subtasks, the final score will be based on the last submission.

The contest is rated for everyone, you will be count as rated only if you opened at least one problem.

We are looking forward to your participation!

UPD1: The contest will start in 40 minutes.

UPD2: Congratulations to the winners!

1. liuhengxi
2. hhoppitree
3. jiangbowen
4. zjy2008
5. cmk666

Goodbye, Jiachen!

We will host the Goodbye Jiachen contest! The contest contains $$$5$$$ problems to be solved in $$$5$$$ hours.

The year 2024 marks the end of the Chinese Lunar Jiachen Dragon Year, with Lunar New Year's Eve symbolizing its conclusion. The upcoming year will be the Yisi Snake Year, where the snake represents wisdom and the cycle of rebirth.

As time passes, UOJ continues to embrace new milestones. From Goodbye Jiawu to Goodbye Jiachen, we have witnessed UOJ's growth and changes over the past decade.

This contest will take you into the world of Poker Kingdom. You will face challenges alongside five poker card characters, writing your own chapter of victory.

• Contest link: https://uoj.ac/contest/93
• Start Time: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20250127T1300&p1=33&ah=5
• Writers: Gellyfish, miao22, Melania
• Testers: orzdevinwang, emptyhope, registeretsiger, yaoxi
• Duration: 5 hours
• Difficulty: like CF Div.1 contests (maybe slightly harder)
• The point values: 100-100-100-100-100

The contest will follow the IOI-style rules: Each problem can be submitted up to 50 times, and scores can be viewed in real-time. All the problems will have subtasks, the final score will be based on the highest-scoring submission.

We are looking forward to your participation!

Q&A

Q1: What can I do if I can't understand Chinese?

You can change the website to English at the bottom of the website.

We don't have English statements for problems now, sorry! But ChatGPT may be helpful for translation.

UPD: Congratulations to the winners!

1. liuhengxi
2. hhoppitree
3. PersistentLife
4. hos.lyric
5. qiuzx

Hello everyone! As you might know, World Tour Finals 2022 will take place on Sep 8th and 9th in Tokyo. Let's share your predictions here!