abcdqwerty12345's blog

Heavy Cheating in Educational Codeforces Round 115 !!!
By abcdqwerty12345, history, 3 years ago, In English

I did not give today's contest today but accidently I looked at the scoreboard and found a lot of submissions for problem A, B, C , D which were much higher than usual.

Screenshot-2021-10-10-at-4-40-05-PM

Hence, I looked online and found that all the solutions for the first 4 problems were leaked.. HERE are the screenshots. I don't want to share the link of the website , it's just for reporting

Screenshot-2021-10-10-at-4-29-17-PM

PROBLEM — D Training Session Solution

Screenshot-2021-10-10-at-4-28-11-PM

PROBLEM — C Delete Two Elements Solution

Screenshot-2021-10-10-at-4-28-28-PM

PROBLEM — B Groups Solution

Screenshot-2021-10-10-at-4-28-43-PM

PROBLEM — A Computer Game

Screenshot-2021-10-10-at-4-28-57-PM

  • Vote: I like it
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  • Vote: I do not like it

Comments Comments (106)
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3 years ago, # |
  Vote: I like it +94 Vote: I do not like it

i hope most of the cheaters just copy pasted the solution and didn't change anything.

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3 years ago, # |
  Vote: I like it +84 Vote: I do not like it

'Only for educational purpose'

Seriously?

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    3 years ago, # ^ |
      Vote: I like it +39 Vote: I do not like it

    The contest is called "educational" contest so it is 100% for educational purpose.

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      3 years ago, # ^ |
        Vote: I like it +27 Vote: I do not like it

      lol Yeah !! But guys get Dijkstracted. :) easily.

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3 years ago, # |
  Vote: I like it -54 Vote: I do not like it

damn thats bad(like the round)

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3 years ago, # |
  Vote: I like it +7 Vote: I do not like it

This is straight up disappointing. D getting this many solves definitely caught my eye!

Some Of the Contributors
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    3 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    I am disappointed that even a not so fellow blue would resort to that. Society is fucked man

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      3 years ago, # ^ |
        Vote: I like it +4 Vote: I do not like it

      They are blue because they resorted to that

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        3 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Maybe, but by the time of submission and his rating graph i assume he was afraid of demoting and copied the code in the last second. If he constantly cheated he would've submitted earlier and with more changes in the code

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    3 years ago, # ^ |
      Vote: I like it +17 Vote: I do not like it

    Actually I think today's D was easier than Friday's D, and back then it also had 1500 solvers, which was much more suspicious to me

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      3 years ago, # ^ |
        Vote: I like it +3 Vote: I do not like it

      I also think today's D was easier than usual. I'm actually a little surprised with the few number of solves of D, and I associate this with fewer participants.

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      3 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      That was exactly copied problem from INOI 2021 and it's solution of all contestants were public on contest site at codechef

      Although it is still suspicious because in INOI there are extremely few submissions during the contest

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      3 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      D is a known problem. I remember 3 or 4 similar problems with exact same solution. It's this type of problem that needs to be solved 1 time only so the next time you know how to deal with it

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        3 years ago, # ^ |
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        Aren't most educational round problems like that ? They are "educational" rounds after all :)

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          3 years ago, # ^ |
            Vote: I like it +9 Vote: I do not like it

          i don't know. i hate educational rounds. i wrote that one because i need rating :D

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    So it isn't too much to hope for a significant ranking improvement after the plag-tests are run, ig.

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    3 years ago, # ^ |
      Vote: I like it +16 Vote: I do not like it

    All submissions have integer overflow I guess. As they are multiplying size of two vectors directly without typecasting.

    Even the leaked one did the same mistake

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      3 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      I used vector size in my code, too. Things go well on my computer. However, the same code reports a WA 14 on codeforces. Can you explain further about the issue?
      WA14:131482168. Hacked: 131448614. Their test cases are the same, which is generated as follows:

      code that generates test cases
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        3 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        size_t is unsigned long int and on your compiler it may be compiling as 64-bit integer but not on cf, try using c++ 17 (64). I submitted your code with c++ 17 (64), got accepted

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3 years ago, # |
← Rev. 2   Vote: I like it +3 Vote: I do not like it

I don't want to share the link of the website

THANK YOU! FINALLY SOMEONE SMART!

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3 years ago, # |
  Vote: I like it +5 Vote: I do not like it

How will you report that website??

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Can't.

    It's there for a long time. They first upload videos on Youtube showing the solutions and post it in their website.

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      3 years ago, # ^ |
        Vote: I like it +17 Vote: I do not like it

      Actually probably it can be DMCA'd because the problems are copyrighted by codeforces

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3 years ago, # |
  Vote: I like it +6 Vote: I do not like it

Color me surprised! (and Cyan :P)

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3 years ago, # |
← Rev. 2   Vote: I like it +40 Vote: I do not like it

Cheating increased because of dumbos like you. Many people who are cheating now wouldn't have got the idea to look for answers online if you ppl haven't posted blogs like these.

Cheaters don't stop cheating by reading blogs like these, but more people will take that path instead.

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    3 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    Does CF's Plag-Checker only compare submissions of participants with one another or are some of the leaked solutions from websites/apps (validated with the help of timestamps) also considered?
    If they aren't being considered right now, maybe there can be a way for users to make submissions flagging these leaked solutions (with timestamps) in the period between the plag-check and the conclusion of the contest?

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    3 years ago, # ^ |
    ← Rev. 2   Vote: I like it +3 Vote: I do not like it

    It is said that, "There is no such thing as bad publicity" XD.

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3 years ago, # |
  Vote: I like it -56 Vote: I do not like it

I am sure most of the cheaters(as well as the site author) are Indians. Stop spoiling the platform for all of us.

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    3 years ago, # ^ |
      Vote: I like it +15 Vote: I do not like it

    What do you want exactly? Should every Indian leave codeforces? If no, for what reason would you bring nationality in a discussion about cheaters?

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    3 years ago, # ^ |
      Vote: I like it +6 Vote: I do not like it

    lol wtf !

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    3 years ago, # ^ |
      Vote: I like it -13 Vote: I do not like it

    I agree. Cheating happens mostly in India.

    And it all started because of this and this

    PS: The videos are in Hindi. So you won't be able to understand what they are saying...

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      3 years ago, # ^ |
        Vote: I like it +9 Vote: I do not like it

      India's population in largest in world . Even India and china combined population is 1/3 of world population . By watching these fucking piece of shit you can't blame whole country.

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      3 years ago, # ^ |
        Vote: I like it +39 Vote: I do not like it

      Damn, the guy introducing the first video should considering becoming an auctioneer or a rapper...

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    3 years ago, # ^ |
      Vote: I like it +14 Vote: I do not like it

    I m also Indian ,and the above statement said by Itami-san is the sad reality of India because of the fact they think showing of 4-5 star or blue/cyan on there resume will get them better chance at Placements ,this hyped up when many placed in good company on Youtube started telling 4-5 star or master/expert will get easily shortlisted for interview, and that's how everything began.

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    3 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    Hmm, I do get the interview part, a lot of people use CP as a means to reform their problem solving skills. Also, there are a lot of top performers from India in almost all contests, so it's not entirely right to judge people with some videos(or my comment for that purpose).

    The only possible solution could be introduction to CP at a relatively earlier age — before university or late high school days — that might change the perception of CP being an interview tool to a competitive sport.

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    3 years ago, # ^ |
      Vote: I like it +4 Vote: I do not like it

    Ngl 99% blogs related to cheating on CF are from India or involves Indians.

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      3 years ago, # ^ |
        Vote: I like it +13 Vote: I do not like it

      And 100% of them are related to humans. That doesn't mean that all humans are rotten.

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    3 years ago, # ^ |
      Vote: I like it +2 Vote: I do not like it

    No one here is criticising ALL the Indians or entire India, neither does it mean that all the Indians should be banned. It's just a statement that MOSTLY Indians are cheating. If you find it so insulting, then there's definitely some truth in it.

    It's just honest criticism, I'm not sure why the arrogant replies here?

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3 years ago, # |
  Vote: I like it +35 Vote: I do not like it

I think Div1 contests are much better if you want a fair contest. most of the cheaters are specialist and below

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    3 years ago, # ^ |
    ← Rev. 2   Vote: I like it +40 Vote: I do not like it

    It is probably true.
    Yet advising to get to div1 to not compete with cheaters is pretty much like "better be healthy and rich than sick and poor"

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    3 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Hoping to push to Div.1 soon! While losing some rating points to cheaters doesn't really mean much to me, I'd like to participate in a pool where there's a common respect for platform integrity and fellow participants.

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    3 years ago, # ^ |
      Vote: I like it +59 Vote: I do not like it

    Dude there are cheaters in red lol

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

May I know what is the standard practise for dealing with cheaters? Compare the code? Timestamps? pls

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3 years ago, # |
← Rev. 2   Vote: I like it +21 Vote: I do not like it

I wanted to hack some solutions on D and found these submissions: 131451583, 131451918, 131445055, 131445378, 131446713, 131450007, 131456045, 131444023, 131447078, 131450582, 131446514, 131453109. You can find more here and here

UPD: Lol, they are all hacked now. Someone shared a wrong solution.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

If these cheaters are not severely punished, Codeforces rounds will be boring by these cheaters sooner or later.

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3 years ago, # |
  Vote: I like it +10 Vote: I do not like it

Maybe the statement $$$ (top[i].size()-1)*(dif[j].size()-1) $$$ is hackable because it would return an unsigned int which may not fit for $$$2*10^5 * 2*10^5$$$

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    3 years ago, # ^ |
    ← Rev. 2   Vote: I like it +1 Vote: I do not like it

    How to upload this test? I created this test but size is too large (1.7 MB) to use as hack.

    Edit : Got it, we can upload a generator as well

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Can we discuss hacks while Hacking Period is not Over?

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      3 years ago, # ^ |
        Vote: I like it -10 Vote: I do not like it

      There are no points for hacking in educational and div 3 rounds

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    I am not sure about this one. vector::size returns a size_t (same as unsigned long int) value which will not overflow. Can anyone tell the hack tc for these solutions?

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      3 years ago, # ^ |
        Vote: I like it +3 Vote: I do not like it

      Hacked about 6 solutions using this

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        3 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        hey do you know why isn't it working on my code?

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          3 years ago, # ^ |
          ← Rev. 2   Vote: I like it +11 Vote: I do not like it

          So it turns out that unsigned long int is 32-bit on CF's 32-bit compilers and 64-bit on the 64-bit compiler, which is what you used (you can check this on custom invocation). So it overflows on the submissions which were submitted on C++ 11/14/17 but is fine with C++17 64 bit (thanks to aryanc403 for telling me this).

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            3 years ago, # ^ |
              Vote: I like it 0 Vote: I do not like it

            Thanks a lot, i was lucky today.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I made this account to comment stuff that might come across as controversial. You just cant simply end cheating at all. Proof? Look at big games like FIFA and COD and all that bunch you'll find tons of cheating going on with ease and they're way bigger and more developed than codeforces and that is not bad on codeforces' side but rather proof that eradicating cheating all together is just impossible. Now you might ask so what to do? Simply just dont care anymore. Honestly at this point it is not worth it at all to just feel anything towards any type of online contest. Cheaters will be there no matter what and blogs like these only open more eyes upon such resources. Because why will any newbie just bother when he can just see thru the blog this type of stuff then put any effort? Add to that there are more issues to deal with than cheating. Have you seen the state of round 3 contests? literally the worst place to ever try and put effort in. 2 day old accounts solving all the tasks with ease, sounds suspicious yet you never hear of it. Also these solutions dont come out of thin air, cheaters are simply not this capable so if you really want to solve it get to the root and find who puts out free AC code that is seemingly well thought and coded than a bunch of cheaters that are clueless headless chickens. Also at this point we see a new cheating blog every week is it really worth it to boil your blood anymore or just care? Just do the right thing and stop caring so much about a number on an internet site that holds no weight in real life. Until we see action against such people then I dont think it's really worth it to keep shouting. Btw, in no way i mean any disrespect against mike it's just and impossible task and that needs to be admitted.

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    2 day old accounts solving all the tasks with ease, sounds suspicious yet you never hear of it.

    Maybe these accounts are just new accounts registered by some strong contestants for competition.

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      3 years ago, # ^ |
        Vote: I like it +4 Vote: I do not like it

      That is wrong though. Tell me what is the difference between that and some newbie having another account and uses both in contests? Nothing. Moreover, it means some insecure topcoder is using his power to steal ratings from others who might not be as good. Still a horrible thing to do.

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        3 years ago, # ^ |
        ← Rev. 2   Vote: I like it 0 Vote: I do not like it

        Tell me what is the difference between that and some newbie having another account and uses both in contests?

        Who told you that if a person registers multiple accounts, he must use them at the same time in a contest? Can't you just use one account in a contest? According to what you mean, if a person has two accounts at the same time, he is cheating? That's obviously wrong.

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          3 years ago, # ^ |
            Vote: I like it 0 Vote: I do not like it

          if a person has two accounts at the same time, he is cheating? That's obviously wrong.

          Every square is a rectangle, but not every rectangle is a square. Every plagiarist is a cheater, but not every cheater is a plagiarist. The users of multiple accounts are just a different variety of cheaters. Some of them do this to gain an unfair advantage for their main account. The others only harm the system without any direct benefit for themselves. Either way, having two accounts at the same time is forbidden by the rules and there's a good reason for that.

          Imagine a plagiarist creating a new account with a random name, submitting copy/pasted solutions with some obfuscation and then immediately abandoning this account after the contest. Does he gain any advantage for himself by doing this? No. Does only sabotaging the system without any personal gain magically make this behaviour acceptable? I don't think so. But the owners of multiple accounts may disagree, because this is similar to what they are doing.

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          3 years ago, # ^ |
            Vote: I like it 0 Vote: I do not like it

          Btw it is prohibited by Codeforces rules to have two accounts

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        3 years ago, # ^ |
        ← Rev. 2   Vote: I like it 0 Vote: I do not like it

        I mean, you're probably not that justified in claiming that "someone is new to codeforces AND is not another account of another user" == "someone is new to comp programming" -- after all, cf isn't the only such platform out there. Plus, if someone solves all the tasks, it is unlikely that it is from cheating -- how often do you see 3000-difficulty problems' solutions leaked? Who would be able to leak them?

        edit -- my bad

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          3 years ago, # ^ |
            Vote: I like it +1 Vote: I do not like it

          you totally missed my point. It's okay I'll boil it down. A lot of the accounts you see in Div3 contests that are new are never touched afterwards basically meaning that the account was only made to participate in this contest then it is thrown away. This is sabotage of the contest and cheating its integrity. Plus I am not implying they cheated as in copying code but as in participating as someone who they arent in order to sabotage the contest. People like these take places of rightful people decreasing their rating. If the case as you are implying this means that this account will remain active afterwards and participate more but that is not the case these accounts are thrown away and not used after and you can look them up and see that.

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            3 years ago, # ^ |
              Vote: I like it 0 Vote: I do not like it

            thanks for making it clear -- my bad

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3 years ago, # |
← Rev. 2   Vote: I like it -77 Vote: I do not like it

Upvote this comment if you support banning Indians from online contests.

Good lord, tons of downvotes from Indians!

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    3 years ago, # ^ |
      Vote: I like it -11 Vote: I do not like it

    Even if you said that about other race or nationality, I would punch you in the face the hardest I could, not thinking of the consequences. Being racist is so fucking retarded, fuck you, bitch.

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      3 years ago, # ^ |
        Vote: I like it -24 Vote: I do not like it

      LMAO

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        3 years ago, # ^ |
          Vote: I like it -30 Vote: I do not like it

        Funny right? Dumbfuck. You're a shitty pupil as well, couldn't code shit to even get to blue even in 17 fucking months, should've known who I was replying to. LMAO

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          3 years ago, # ^ |
            Vote: I like it 0 Vote: I do not like it

          should've known who I was replying to

          Lol you replied again, making your point completely invalid.

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            3 years ago, # ^ |
              Vote: I like it -31 Vote: I do not like it

            Listen, idiot, that was purely for shitting on your peanut brain. I just find racist cunts disgusting. You're a loser anyway.:) And an alternative to all my comments to you would be- shhh, pupil

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              3 years ago, # ^ |
                Vote: I like it 0 Vote: I do not like it

              That "peanut brain" punch was so mature

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3 years ago, # |
  Vote: I like it +8 Vote: I do not like it

Punishment suggestions for cheaters: 1) Rip of their arms. 2) peel their skin 3) place them in HF. Peace :)

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3 years ago, # |
← Rev. 2   Vote: I like it +9 Vote: I do not like it

wow. insert variables by yourself and It is only for educational purpose. does this even make any sense?

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3 years ago, # |
  Vote: I like it +7 Vote: I do not like it

This is absolutely madness, almost every contest is breached by cheaters, the fact that we as a community are unable to do anything makes these cheaters grow each passing day.

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3 years ago, # |
← Rev. 5   Vote: I like it 0 Vote: I do not like it

Soooooo.... Why bother? D solution is poorly written here, so it will be hacked, isn't it? )))

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Finally someone who is actually sensible. D needed better constraints. Hacked solutions are a 100% right so far it is just int overloading that hacks them not actual cases.

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      3 years ago, # ^ |
      ← Rev. 4   Vote: I like it 0 Vote: I do not like it

      vector dif[i].size() and top[i].size() aren't long-longs, so their product can overflow — for example when they both are 10^5 each.

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      3 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      To explain, if the authors of problem D really wanted the numbers to go so high they would've done so themselves and it is a very common practice in CF rounds and nearly every problem has those type of testcases. But the testcases this time don't go this high meaning that the authors probably didn't want them to reach such number for a reason (int overflow). So basically meaning either the constraints are unclear or the testcases are poorly written in either way it doesn't negate the solutions as they're correct solutions.

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        3 years ago, # ^ |
        ← Rev. 3   Vote: I like it +12 Vote: I do not like it

        But then, there would be no "educational" hacking! It would be bad, very bad )))

        Hackable Edu's is a long tradition )))

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3 years ago, # |
  Vote: I like it -16 Vote: I do not like it

Hi, Can you please share the link to this website?

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3 years ago, # |
  Vote: I like it +2 Vote: I do not like it

On the other hand, I was detected as a cheater because on round 747, my B submission coincides with horizon2 B submission. Note that I use the template of jiangly and the B's solution is way too simple enough to put me into this situation. If I am faster in implementation, maybe horizon2 is punished :)) Have a nice day.

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3 years ago, # |
  Vote: I like it +2 Vote: I do not like it

People like me are dying of solving $$$2$$$ or $$$3$$$ problems during contest but couldn't find a proper approach sometimes or misses one or two corner cases or takes longer time to solve the problem each time hence decrease in rating and there comes these guys. Just copy paste others solutions and become $$$blue$$$ overnight.

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3 years ago, # |
  Vote: I like it -7 Vote: I do not like it

abcdqwerty12345 Why do you even care The number of contests you appeared in are less than the cheating blogs you made. You are just a spam and noting more Please ban him

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3 years ago, # |
  Vote: I like it +5 Vote: I do not like it

Bored From reading these post. Let Them Cheat from now if it gives them happiness, Realy they can't go far beyond CM due to late submission, so clearly they Not Comming in Our way xD.Just Focus On self Improvement :)

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Candidate Master

    We are not even pupil :) :) :) :) :)

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      3 years ago, # ^ |
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      I will Be 2000+ Rated Next Year Same Month guaranteed XD. Marked This Comment For Reminder :):):):)

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3 years ago, # |
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if we hope for better codeforces so act, every one try to hack 5~10 codes this will clean the mass around and they will stop doing it.

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    3 years ago, # ^ |
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    this is only when the cheaters themselves screwed up -- if the cheaters' code is correct then we have no wae

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3 years ago, # |
  Vote: I like it -9 Vote: I do not like it

Have you considered the fact that ABCD were all easy problems?

I solved A in 1 minute, B in 5 minutes, C in 5 minutes, and D in 16 minutes.

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