We will hold JRKSJ Round 9 &「KDOI」Round 7 on Luogu. This is a high-quality unofficial contest on Luogu.

• Contest URL:
• Div. 1: https://www.luogu.com.cn/contest/167920
• Div. 2: https://www.luogu.com.cn/contest/187338
• Start time: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20240815T1400&p1=237
• Duration: 270 minutes
• System: IOI
• Difficulty: Similar to the last 4 problems of Codeforces Div. 1/2 (respectively)
• Writer: wyrqwq, sail_with_pleasure, Otomachi_Una, dqstz, sszcdjr
• Tester: cyffff and above.
• Special thanks to orzdevinwang for developing some of the problems.
• Rated range: Div. 2 is rated for those whose Luogu rating less than 2200. Div. 1 is rated for all.
• Score Distribution: 100-100-100-100-100-100.

We are looking forward to your participation! If you cannot understand Chinese, ChatGPT may be helpful. We are working on establishing an English platform, but it takes time. We plan to complete this task by the end of 2024 or early 2025.

• A tutorial on using Luogu
• A brief introduction to Chinese NOI