Codeforces Beta Round #40 (Div. 2)

16 years ago, hide # ^ |

Where do I add my friends?

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16 years ago, hide # ^ |

Go to their profile and click on the star next to their name.

Their profile is found at:

http://www.codeforces.com/profile/yourfriendsusername

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16 years ago, hide # ^ |

Thank you so much!

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16 years ago, hide # |

Thanks for the really nice problems.

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16 years ago, hide # ^ |

Problems were nice. Even though the round was unrated for me, I would like to know what made me got a Presentation Error in Pretest 5 in problem D.

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16 years ago, hide # ^ |

And I want to know what was pretest 5 of problem C. I submitted my C# code and got WA. I wrote the same thing with C++ and got acc.

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SyFy	16 years ago, hide # ^ \| ← Rev. 2 → +1 show me your code ( http://paste.ubuntu.com ) may be I can help you → Reply

http://paste.ubuntu.com/528276/

16 years ago, hide # ^ |

← Rev. 3 →

THANKS

Here It is:

I'm an absolute beginner in C#

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SyFy	16 years ago, hide # ^ \| 0 I think you have trouble in this part of your code: <pre> if(input.Substring(i,2)=="at") { input=input.Substring(0,i)+"@"+input.Substring(i+2); } </pre> reread the statement carrefully ;) → Reply

16 years ago, hide # ^ |

What's wrong with it?

input.Substring(0,i) is from index 0 to i-1 and input.Substring(i+2) is from i+2 to end. "at" at indexes i & i+1 was replaced by "@"

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16 years ago, hide # ^ |

← Rev. 2 →

I just understood it.

You're right :D

I have a missing break

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SyFy	16 years ago, hide # ^ \| +4 yep :) small mistake. → Reply

SyFy	16 years ago, hide # ^ \| 0 but what will be the answer for such test: dotdotatatatatatatatdotdot ? → Reply

16 years ago, hide # ^ |

← Rev. 2 →

The ans: dot.@atatatatatat.dot
(Sorry! you did not ask the really ans. My mistake)

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astrovsky

16 years ago, hide # ^ |

dot.@atatatatatat.dot

вот ответ на этот тест

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SyFy	16 years ago, hide # ^ \| +5 в вышеприведенной программе ответ не был бы таким :) → Reply

16 years ago, hide # ^ |

Here's my code for problem D, in case someone can spot my mistake. Thx in advance.

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16 years ago, hide # ^ |

I can't see any code

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16 years ago, hide # ^ |

Sorry, I forgot to paste the link :(

http://paste.ubuntu.com/528290/

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SyFy	16 years ago, hide # ^ \| +1 really nice problems! thanks to authors and CodeForces! well done! → Reply

16 years ago, hide # |

I think there will be many pepele died in problem B.

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samshu

16 years ago, hide # ^ |

Well, i've still not understood the problem statement for problem B
!

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16 years ago, hide # ^ |

I missed "not more than once" .The problem mean you can buy and sell only one time or did not do it.Find the max value you can got.

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16 years ago, hide # ^ |

A simple greedy algorithm works :D

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16 years ago, hide # ^ |

Yeah, the problem is simple .Many people make a mistake on what the problem mean.

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16 years ago, hide # ^ |

I think i can only buy once and sell once before.
But finally i got WA...
Does the problem means, i can buy many times, but sell only once?

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16 years ago, hide # ^ |

Even if you can do so, the best possible thing to do is to buy once and sell once :D

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sygi	16 years ago, hide # ^ \| 0 That's not true. In the test: 4 4 1 2 1 2 you could get more than 8 using 2 sells and buys. By the way, that's a test, which gave me 3 hacks :P → Reply

checkmate

16 years ago, hide # ^ |

I don't get the point

So finally, can I sell many times ?

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16 years ago, hide # ^ |

No, You simply can't

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16 years ago, hide # ^ |

I did not got the point either.You can sell only "not more than once".

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16 years ago, hide # ^ |

that means, you can only sell once!!!

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16 years ago, hide # ^ |

we can not use 2 sells! the statement say only 1 sell....

when greedy, use:
    int cas = b / min[i];
    int t = b + cas * (data[i] - min[i]);
    if (t > max) max = t;

min[i] is the min number in the left side.

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16 years ago, hide # ^ |

i find my bug, thank you very much.

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nab	16 years ago, hide # \| ← Rev. 4 → 0 Looks like a lot of people misread problem B and thought that you could sell as much as you wanted. (bug: commenting seems to not work (comment is blank) from chromium?) → Reply

16 years ago, hide # ^ |

It's not a bug in codeforces. I'm writing these in Chromium.

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anas17in

16 years ago, hide # |

Can there be more than one word in problem A. I got my solution hacked but still cannot understand the reason

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SyFy	16 years ago, hide # ^ \| 0 Can there be more than one word in problem A nope → Reply

anas17in

16 years ago, hide # ^ |

ok then here is my solution
http://paste.ubuntu.com/528284/
Kindly explain the problem.

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sygi	16 years ago, hide # ^ \| 0 a aa Is the contr-example. BTW - it's my first contest on Codeforces, so i think i should say 'hello' to everybody, and thank you for the exciting contest! → Reply

16 years ago, hide # ^ |

the length of the string a and the string b can be different.

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16 years ago, hide # |

How is the Rating calculated? what about the colors (sergeant,lieutenant,etc) ?

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PavelKunyavskiy

16 years ago, hide # ^ |

See this post about raiting and this about colors.

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kyo_key

16 years ago, hide # |

← Rev. 3 →

what is D test 5?

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16 years ago, hide # ^ |

Please give test case number 8,too

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16 years ago, hide # ^ |

I got Presentation Erro in that one. I would really like to know what went wrong with it.

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kyo_key

16 years ago, hide # ^ |

i have solved my bug .
PE maybe you can get the right value, but the wrong path.

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16 years ago, hide # ^ |

It could be. Anyway, that would be a confussing judge response, in that case a wrong answer should be expected.

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scientist1642

16 years ago, hide # |

admins answer my questions fast during contest , thanks for that.

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asif_iut

16 years ago, hide # |

what is the idea for solving problem E??

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