ndkhaivn's blog

My codes were skipped without a proper reason?
By ndkhaivn, history, 8 years ago, In English

Codeforces Round 388 (Div. 2) First at all, I want to complain about compiler!

Same code for problem D, I tried on my PC and on ideone, it's all fine. But it got CE on Codeforces compiler, then I changed lang to G++14 6.1.0, it got passed. So I got 2 wrong submissions and that wasn't my fail.

But that's no the worst!

When system testing end, I got AC at A B C D. And while i'm waiting for rating change, I found that my codes were skipped, without a announcement or reason.

Seriously, I SOLVED PROBLEMS ON MY OWN!

I'm looking forward to receiving feedback from pitfall and thank you in advance! GG!

UPD: This is my fail not setting privacy on ideone, but plz don't down vote, I had a really bad night, I don't wanna get negative contribution anymore :(

  • Vote: I like it
  • +13
  • Vote: I do not like it

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

As you said, you tested your code on ideone. Probably, your codes were made public there and someone copied them.

→ Reply
  • »
    »
    8 years ago, # ^ |
      Vote: I like it -10 Vote: I do not like it

    But this is caused by Codeforces's compiler error. I never meet this case before.

    → Reply
    • »
      »
      »
      8 years ago, # ^ |
        Vote: I like it +24 Vote: I do not like it

      fofao_funk is talking about the reason your submissions were skipped (someone copied them from ideone and submitted them from his/her account).
      Compilation error does not add any penalty

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

How about testing your code on ideone and you forgot to set it private? Like this http://codeforces.me/blog/entry/48584

→ Reply
»
8 years ago, # |
  Vote: I like it +30 Vote: I do not like it

First, you don't get any points deducted for compilation errors. This is the official rule regarding this:

" If the result of the judging is Compilation Error, Denial of judgement (or similar) or if the solution didn't pass the first pretest, then this solution won't be considered in calculating results. " Link

Second, surely someone saw your code on ideone and submitted them from his/her account. You should have never left your code public at ideone during a contest in the first place.

Take this as a lesson and never keep codes public on any code sharing site or anywhere on the internet during a contest in the future.

→ Reply
»
8 years ago, # |
← Rev. 2   Vote: I like it +17 Vote: I do not like it

If I didn't get CE, I'd not have it tested on ideone. Anyway, thanks for replying, I'll take this as my worst experience!

btw, these are some users used my code

humblecool

unbelievable02

RoadToMaster (Yes, Master ...)

→ Reply
  • »
    »
    8 years ago, # ^ |
      Vote: I like it +40 Vote: I do not like it

    Lmao humblecool is indeed so cool. His last 50 submissions got skipped, and yet he does not give up. May be someday he will beat the system...

    → Reply
»
8 years ago, # |
  Vote: I like it +20 Vote: I do not like it

out of curiousity, why did some people write their code in ideone instead of their local computer?

→ Reply
  • »
    »
    8 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    As I said, due to Codeforces compiler's error, I have no idea what is going on, then I tried on ideone to make sure that it's not my error

    → Reply
»
8 years ago, # |
  Vote: I like it +7 Vote: I do not like it

Would you mind sharing your compilation error messages? Looks suspicious. I've tried to submit one of your codes 23159820 myself (23172978) and Compilation Error feedback looks empty, the only message is Can't compile file:

→ Reply
  • »
    »
    8 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    It's empty, too.

    Custom Invocation

    → Reply
  • »
    »
    8 years ago, # ^ |
      Vote: I like it +2 Vote: I do not like it

    23159820 and 23159992 got skipped, so I can't show error messages, but they are same as above. Thanks for consideration!

    → Reply
  • »
    »
    8 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    I tried to compile the code on my laptop, and it took nearly 10 seconds with the flag -std=c++11 and used more than 2 GB of memory. Either the long time or the memory usage might be the reason why Codeforces aborted the compilation.

    Appenrently there is a bug in gcc (link). It can't handle arrays of pairs in tuples. 

    >>> /usr/bin/time -v g++ -std=c++11 test.cpp 
	Command being timed: "g++ -std=c++11 test2.cpp"
	User time (seconds): 9.22
	System time (seconds): 0.48
	Percent of CPU this job got: 99%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:09.71
	...
	Maximum resident set size (kbytes): 2304092
	...

    Tested with gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4).

    This shouldn't be a problem anymore with version 6.2. Or at least not a big problem. Only 1.5 seconds time and 0.5 GB memory usage. 

    >>> /usr/bin/time -v g++-6 -std=c++11 test2.cpp 
	User time (seconds): 1.51
	Maximum resident set size (kbytes): 530572
    → Reply
    • »
      »
      »
      8 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Which version of the the compiler does Codeforces use?

      → Reply
    • »
      »
      »
      8 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      You use 32bit compiler, aren't you?

      → Reply