Satoru's blog

By Satoru, 7 months ago, In English

UPD: it's now rescheduled! thank you all for the support.

Hello Codeforces,

I didn't want to publish this blog during these circumstances, as it's the last thing to care about, but I'm publishing it hopefully ACPC organizers see it.

Last Saturday, we got an email saying that the ICPC world finals, which were supposed to be in 11 days in Sharm El-Sheikh, got rescheduled to a later time. And it was expected that the ACPC, which is supposed to be in 17 days in the same hotel, would get rescheduled too. but apparently the competition is still on its previously scheduled date!! I would like to note that ACPC is scheduled to be in the same hotel as ICPC.

Let's talk about it from many perspectives.

From the travel perspective, sadly while talking I will partition Palestine into the West Bank and Gaza, but we're one nation and stand together with each other. Firstly, two teams from Gaza are supposed to participate in ACPC this year, and surely, they will not be able to come if they even stay alive after 17 days, may they stay safe and meet them in the closest time. Secondly, there are more than seven Palestinian teams from the West Bank who qualified to ACPC and will not be able to travel because the travel will be unsafe, and I'm even assuming that Egypt will give us visas if we apply, which is unlikely. Thirdly, I don't know about Egyptians or the rest of the countries in ACPC whether their travel to Sharm El-Sheikh would be easy as it's inside Sinai or not.

From the mental side, I would like to note that I'm not coming to victim role play, but I don't think that there's a contestant will be ready mentally to participate in a competition right now, and have fun and dance there, and stay in a hotel, and enjoy their life, while some other contestants and other people in Gaza can't even find clean water to drink, and they don't even know whether they will stay alive to the next moment or not, and at any second an Israeli airstrike may fall on them, ending their dreams and ambitions. I can't imagine that the contestants will be competing in a contest, and after they finish and check their phones, they will find a new massacre committed by Israel happened in Gaza, Or stay in the closing ceremony waiting for results and checking their phones to see that the number of people killed in Gaza gets heavily increased. Or even swimming in the water sea during the excursion, while people in Gaza swim in a blood sea. Please don't think it's easy for me to write this. Of course, it's very hard and depressing for me as a Palestinian to write this about my friends, relatives, and fellow CPers who live in Gaza, but that's sadly the situation.

In the end, I'm wondering why I've to write this blog, even though delaying the competition is an obvious thing to do, and as ICPC which is international and a much bigger competition got delayed, ACPC could be delayed too. I know that the hotels got booked, and places and all of this costs money, but as ICPC got delayed in the same place and hotel, I believe that ACPC could be delayed too.

Lastly, I would like to say that if ACPC hasn't rescheduled, all Palestinian teams will have to boycott and not participate. I'm calling other ACPC teams to boycott too and comment here stating that they will boycott, maybe this will put more pressure on organizers to delay the ACPC.

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By Satoru, history, 7 months ago, In English

Requested to publish from Basilhijaz:


Hello, I am Basilhijaz. I participated in lots of Codeforces rounds and the last one I did was Educational Codeforces Round 155 (Rated for Div. 2). Unfortunately, I was trying to login to my account today and got the message "User is disabled by administrators". I checked my email and it looks like I was accused of cheating in that specific round. Apparently my Submission on Problem B 224888371 is so close to LetsPractice's Submission 224901176.

This problem we both got accused of copying from each other is B in an Educational round which means solutions can get actually really close and if you notice the solutions are so short which increases the probability of matching.

Previous Accuses of Cheating Attempts (Problem, My Submission, Similar Submission/s)(problem classification):


  • Most of the problems I got accused of cheating are <= *1400.

  • The solutions are quite short and easy to come up with.

  • All cheating attempts are with random/different people having no connections with.

  • I never publish my code online during contests or use or any similar websites.


  • ICPC finalist for the upcoming ICPC 2022-2023.

  • IOI Participant twice (2019 and 2020).

  • Joined Codeforces more than 5 years ago.

  • Did 231 contests on Codeforces.

  • Solved Over 2000 problems on Codeforces.

Actions I previously took for previous accusations:

Mike replied to my comment: "lightning rarely strikes the same point twice". Well, looks like it hit five times the same place. I am sad to see all of this happening right before ICPC and preventing me from practicing and doing regular contests.

Regardless of the effort done to build the cheating system, I think the algorithm needs quite improving.

After writing comments and messages and not seeing any action happening and getting almost every time my solutions to get skipped and me losing ranking with no action, I hope this time it's different.

CC: MikeMirzayanov


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By Satoru, 3 years ago, In English

Hello codeforces

Can you help me solve this problem:

Given an array of size $$$k$$$, the sum of it's elements is equal to $$$n$$$, print a binary string of size $$$n$$$ ('$$$1$$$' if you can create $$$i$$$ by taking a subset from the array, '$$$0$$$' otherwise)


UPD: Constraints: $$$1 <= n, k <= 10^5$$$

UPD2: thanks purplesyringa for the solution

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