AHMADUL's blog

By AHMADUL, history, 6 weeks ago, In English

Is it really a bug of the judges??? I have given same input for 2 different accepted codes for the following problem: https://codeforces.com/contest/1771/problem/C But, they gave me different output!

Input: 1 101 2 3 5 7 1 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 101 103 107 109 113 127 131 137 139 149 151 157 163 167 173 179 181 191 193 197 199 211 223 227 229 233 239 241 251 257 263 269 271 277 281 283 293 307 311 313 317 331 337 347 349 353 359 367 373 379 383 389 397 401 409 419 421 431 433 439 443 449 457 461 463 467 479 487 491 499 503 509 521 523 541 4

First code: submission_id- 184778210 Output: NO.

Second code: submission_id- 185537533 Output: YES.

And the valid answer is "YES". But the judges also accepted "NO"!!!

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By AHMADUL, history, 2 months ago, In English

I don't know how accurate my observation is! But, I think there is a bug in the accepted solutions to this problem. For example, let's see the third example: x1=1, x2=4, t1=0, t2=0. Here they say the answer will be unique and that is 2.5 but the answer can be 2 also! Consider, another example: n=3, x1=1, x2=3, x3=11 and t1=t2=t3=0; The accepted code gives answer: 6 (the meeting point). Analysis: |x1-6|+|x2-6|+|x3-6|=13; But, if we choose 2 as the meeting point, then the absolute sum is: |11-2|+|3-2|+|1-2|=11 which is lesser than 13(the accepted output) Could anyone please help me to understand this concept?

Update: Yes, I have understood the concept. I have to minimize the maximum distance among all distances. Thank You.

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By AHMADUL, history, 11 months ago, In English

There is no contest scheduled for the next 8 days in a row. Besides, we had not enjoy a Global round in this month. So, wouldn't it be nice to have a global round before Round #778? (Thank you, Codeforces.)

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By AHMADUL, history, 21 month(s) ago, In English

Last year, Div-4 was held for the first time on this day. Who wants it to be held once again? In fact, there is no scheduled contest for the upcoming few days. That's why I said so.

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By AHMADUL, history, 21 month(s) ago, In English

Eid wishes to all in advance. "*Eid Mubarak*". Wouldn't it be nice to have a contest on the night before the Eid day?

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By AHMADUL, history, 21 month(s) ago, In English

There is no contest before 29th,April.Wouldn't it be nice to have a contest before "Educational Round-108"?

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By AHMADUL, history, 21 month(s) ago, In English

In which situations the verdict column shows "skipped" status? The term is quite unfamiliar to me.So,could anyone please help me.

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By AHMADUL, history, 2 years ago, In English

There is no scheduled contest for the rest of the month.It's a long time, we are not enjoying "Global Round".So far as I think it is high time to arrange a "Global Round" contest and fill a cell on the "Programming Contest Calender".Thank you,Codeforces.

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By AHMADUL, history, 2 years ago, In English

Is there any possibility to arrange another div-4 round or a sequence of div-4 round for us(Newbies and Pupils)? And how much effective div-4 round is for us?(So far as I think,it will increase our confidence level.That is why I said so.)

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By AHMADUL, history, 3 years ago, In English

I was trying to solve problem B1 of Helvetic Coding Contest 2019 online mirror (teams allowed, unrated). I got WA and TLE for a several time.Then I went to standings and found a line from a submission: int f=lower_bound(dg,dg+b,make_pair(a[i],10000000))-dg;
But,I couldn't understand it,,why I have to subtract dg at last??? Now, I am badly in need of help.Someone please explain the above statement.

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