I've tried to report the same issue several times ago.

PLEASE BAN THE BOT

BAN THE BOT IMMEDIATELY

Although many bots are in the judging queue, it seems that CodeForces use more judging server or order the submissions in a more reasonable way, a submissions will run on test #1 about 3 minutes after submit. However, the judging time can even be about 20 minutes or more.

Meanwhile, a new problem appeared. As a lot of bots are submitting their solutions, the statistics about solved number is inaccurate. The number is hugely effected by the bots, and when you try to found a popular problem, you may find a problem that is used by AI as a training data.

To make the statistics reflect the actual situation better, I strongly suggests that the AI accounts should be limited.

To my point of view, those accounts who only submit code generated by AI will have 0 benefit to CodeForces.

And thank you.

Here is a possible way to deal with the AI problem:

I recommend that CF give people with high rating a permission to ban those accounts which are apparently used by AI.

Sorry for poor English.

THE ISSUE IS MENTIONED FOR SEVERAL TIMES BY DIFFERENT USERS.

BUT NO ACTION HAS BEEN TAKEN UNTIL NOW.

CODEFORCES WILL BECOME BOTFORCES.

IS ALL ADMINISTRATOR ON VACATION ???

WE CANT WAIT ANYMORE.

The same thing happens three times these days, and the queue is still full of bots.

The bot is submit at a CRAZY speed.

Only about 10 normal submission can be seen on the first status page.

The affection of the bot is much more than before.

I strongly suggest that we can give some rednames a temporary permission to ban the accounts that have too much submission in a short period.

AND I THANK YOU!

Update — Another advice

Can we limit a user's try on different problems in a short time?

Like a user can just submit on 16 different problems in 10 minutes.

Sorry for poor English, but this thing is EMERGENCY.

The queue of the judge server is full of bots.

The same thing had happened last Saturday night. A blog is publish at that time to complain about this thing, but NO ACTION has been taken until now.

It is OBVIOUSLY that all those account with 10 random characters is bot. Their username is meaningless, and their code style is similar. It seems something like an AI model is testing.

Is it permitted to waste the public judging service on CodeForces???

At last Saturday night, it takes about 5 minutes for a submission to get judged. However, the time increased to more than 20 minutes today. Here is a submission from my friend: 349398173. It hasn't been judged until now, 28 minutes after he submit it.

A lot of people complain about this problem, and this blog is written to show how the thing developed these days.

It's almost unbearable to wait for almost 30 minutes.

So please deal with this problem AS SOON AS POSSIBLE.

THANK YOU.

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Update

The submission I mentioned before is waiting for 45 minutes and not judged until now!

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Update #2

If all the bot account is from the same IP subnet, please ban the IP subnet directly.

When I was solving the problem 674G — Choosing Ads, I got a TLE on #10 as result. The submission id is 348821830.

I tried to generate a data and run my code on my Ubuntu, and it took 5.80 seconds. (The python code to generate the data is at the end of this blog.)

I was once told that O2 can make the code run faster, so I tried to compile the code with option -O2 (the full command was like g++ ./t.cpp -o ./t -O2), it just took 0.73s. I added #pragma GCC optimize(2) into the code, and then recompiled it without option -O2 (the full command was like g++ ./t.cpp -o ./t), however it took more than 5 seconds. (I used the command /usr/bin/time -v ./t < ./t.in > ./t.out to measure the time.)

As you can see the two ways above has a huge difference.

I'm wondering why this phenomenon happened.

Is there some problem in my code or the way I compile it? or it can just happen on my Ubuntu?

Thanks a lot.

#!/bin/python3

from random import *

n=150000
m=150000
k=20

print(n,m,k)
for _ in range(n):
    print(randint(1,6),end=' ')
print()
for _ in range(m):
    o=randint(1,2)
    l=randint(1,n)
    r=randint(1,n)
    v=randint(1,6)
    if l>r:
        l,r=r,l
    if o==1:
        print(o,l,r,v)
    else:
        print(o,l,r)

When I was testing on my Ubuntu, all tests generated by this code will cause the phenomenon above.

Update

I've put #pragma GCC optimize(2) to the first line, then the time reduced to 3.13 seconds, still far more than -O2.

Update #2

I've passed it. I changed the map and vector to simple arrays like a[150005], which seems to be a good way to improve speed. On the local test, it took just about 0.5 second. But why there was such a huge difference on pragma and -O2?

I've create some mashup contest in our group recently, but however, some contestants submit their codes to the original problem instead of the mashup contest by mistake or on purpose, which makes the penalty counting wrong.

I'd like to ask whether there is a way to solve this problem, like set contestant's penalty manually or limit their submission on original problem. And thanks.

To use pbds, I've submitted a code which uses #include<bits/extc++.h>.

It can compile and run on my computer, however, it can't compile on Codeforces platform.

You can see it at 292301911, in which it recieves CE, and return as follow.

Can't compile file:
In file included from C:/Programs/gcc13-64-winlibs/include/c++/13.2.0/x86_64-w64-mingw32/bits/extc++.h:83,
                 from program.cpp:1:
C:/Programs/gcc13-64-winlibs/include/c++/13.2.0/ext/codecvt_specializations.h:42:10: fatal error: iconv.h: No such file or directory
   42 | #include <iconv.h>
      |          ^~~~~~~~~
compilation terminated.

I'd like to ask if we can add iconv.h file to CF platform, and thank you.

First, please allow me to thank MikeMirzayanov for the wonderful CodeForces and Streams.

However, for Chinese users, it's hard to see streams in websites like t.me or YouTube.

So, I am wondering that whether CodeForces can provide some streams on other platforms such as Bilibili.

And thank you.