Hello, Codeforces!

The 17th Zhejiang Provincial Collegiate Programming Contest has ended last weekend (October 17, 2020). The contest was originally scheduled for April 2020 but was delayed due to the coronavirus pandemic. It was eventually decided to hold the contest online in October.

The problems for this contest were prepared by retired ICPC team members of Zhejiang University, and I was the coordinator of the problem-setting group. We are glad to announce that we have published the contest, The 17th Zhejiang Provincial Collegiate Programming Contest, in Codeforces::Gym for you to practice. Feel free to start virtual participation or to solve the problems individually. For virtual participation, the contest is 5 hours in length and follows usual ICPC rules. Team participation is recommended, but it is also possible to participate individually. The ghosts of the onsite participants are available, you may take advantage of it.

My thanks go to:

• Hangzhou Normal University and Zhejiang University, for co-hosting the contest.

• Problem authors: Claris, lsmll, jiangshibiao, shb123, reku, lqybzx, MudCoal, and Sugar_fan.

• MikeMirzayanov for the powerful Polygon system where we prepared the problems.

Hello, Codeforces!

The 2019-2020 ICPC Asia Hong Kong Regional Contest has ended on December 1. Due to the recent social movements in the city, the campus of the City University of Hong Kong, where the contest was originally planned to be hosted, sustained damage and was closed. It was decided to hold the contest in Shenzhen, China instead two weeks before the contest. The contest was eventually successfully conducted in the National Supercomputing Center in Shenzhen. Thirty-eight teams (including two unofficial middle school teams) from China, Hong Kong SAR and Macau SAR participated in the onsite contest. Team CodeChant from Zhongshan (Sun Yat-sen) University won the contest who solved 6 of the 11 problems. However, the contest is actually not that hard. Some strong teams in China were not able to participate in the contest because many universities in mainland China blocked all visits to Hong Kong on political grounds, while some others voluntarily chose not to go due to safety concerns.

The problems for this contest were prepared by retired ICPC participants of Zhejiang University, and I was the coordinator of the problem-setting group. We are glad to announce that we have published the contest, 2019-2020 ICPC Asia Hong Kong Regional Contest in Codeforces::Gym for you to practice. Feel free to start virtual participation or to solve the problems individually. For virtual participation, the contest is 5 hours in length and follows usual ICPC rules. Team participation is recommended, but it is also possible to participate individually. The ghosts of the onsite participants are available, you may take advantage of it.

My thanks go to:

• The RCD, Dr. Minming Li from City University of Hong Kong and staff from National Supercomputing Center in Shenzhen for their tireless efforts in hosting the contest successfully under difficult circumstances.

• Problem authors: lsmll, Claris, jiangshibiao, shb123, reku, lzw4896s, J.T.J.L., lqybzx and Sugar_fan.

• Testers: chenjb, oipotato, Subconscious, chenyanbo and two other members of Zhejiang University ICPC team.

• MikeMirzayanov for the Codeforces platform and the Polygon system where we prepared the problems.

We have prepared an English editorial. Hope you enjoy the problems and feel free to discuss them in the comments.

Hello, Codeforces!

The China Collegiate Programming Contest (CCPC) is a competitive programming contest series for college students in China, organized by the CCPC Committee, which consists of coaches of the competitive programming teams of Chinese universities. It started in 2015, and this year is the 5th edition of CCPC. There are 4 onsite CCPC contests this year, including three regional contests in Qinhuangdao, Harbin and Xiamen, as well as the CCPC Final in Beijing. Many Chinese universities use CCPC as an opportunity to practice before the ICPC regionals.

The 2019 CCPC Harbin Site has recently ended on October 13 in Northeast Forestry University. A total of 272 teams, most of whom were selected from the preliminary online contest, took part in the official onsite contest in Harbin. The problems for this contest were mostly prepared by retired ICPC participants of Zhejiang University, and the head judge was me.

We are glad to invite you to participate in its online mirror: The 2019 China Collegiate Programming Contest Harbin Site in Codeforces::Gym! Please note that the mirror contest will start at Saturday, November 2, 2019, 18:00 (UTC+8). Click on the link to see when it starts in your timezone. We will be able to answer your questions during the mirror contest. The ghosts of the onsite participants are available, so you may take advantage of it.

This contest uses ACM-ICPC rules and of course, it is unrated. Team participation is recommended, but it is also possible to participate individually. As usual for Gym contests, you may register for this contest 6 hours before it starts, and you will be able to virtually participate and upsolve the problems after it ends.

My thanks go to:

• Volunteers and staff from Northeast Forestry University for holding a very successful onsite contest.

• Problem authors: lsmll, quailty, Claris, jiangshibiao, shb123 and reku.

• Testers: izban, 300iq, and many members of the competitive programming team of Zhejiang University, some of them are: Todobe, wxx_louisa, zx2017, SoSad, zhangqingqi and lyk248289469.

• MikeMirzayanov for the powerful Polygon and Codeforces system.

• The CCPC Committee and the sponsors of the onsite contest.

We kindly ask everyone who has already know the problems not to participate or discuss them before the mirror contest has ended. Hope you enjoy the problems!

UPD: Contest has ended, thanks everyone for your participation. Here is the link to the official editorial, unfortunately it is in Chinese. But feel free to ask in the comments if you have any questions about the problems.

Hello, Codeforces.

Today, my friend and teammate jiangshibiao was going to register for the round, but discovered that his Codeforces account was hacked and the avatar as well as the password has been changed. The email could be changed too, but he is unsure right now. I looked at the avatar and immediately noticed it was the same as [user:[user:im0qianqian],2018-08-27]'s avatar, who made a blog post about his account being hacked too.

I think probably the same hacker did it, and there may be more victims. So I would like to invite MikeMirzayanov to look into the issue and possibly help my friend get his account back. Also, I would advise users who have weak passwords to change the password immediately.

Also, jiangshibiao and me are onsite at Petrozavodsk Camp right now, so maybe someone can meet him in person if needed to verify his identify.

UPD Aug. 29:

The hacker sent me a message in Chinese with the account of im0qianqian claiming that he changed the password and the email back. Then im0qianqian sent me another message saying that he got his account back and the previous message wasn't sent by him. Unfortunately, my friend jiangshibiao tried the original password but it still does not work, and he forgot what email address was used when registering his account. Therefore he is still locked out of his account. Any help from Codeforces administration is still greatly appreciated.

UPD2: Apparently the hacker did not really change the password and email back, as the "last visit" of jiangshibiao is two days ago.

UPD Aug. 31:

The hacker changed the email back and my friend got back his account. Thanks everyone who replied in the post.

The USACO 2013 March contest is available now. Participation is free, and open to all.

There will be 3 problems and you will have 4 hours to complete them.Supported languages are C, C++, Pascal, Java and Python.

You can take the contest during any contiguous 4-hour block of time you want.

The contest is open until until March 11.Check the deadline to start the contest in your timezone here.

Link to Contest Page

Please don't discuss the contest problems before it ends(deadline + 4 hours).

UPD:Contest is over.Now you can discuss the problems.

UPD2:Official results