ma5termind's blog

HackerRank HourRank 7
By ma5termind, 9 years ago, In English

Hi Codeforces !

I am glad to announce seventh HackerRank HourRank round! The contest will be held on 18:00 UTC Friday, April 1 2016. Contestants will be given 4 problems and 1 hour to solve them. You can sign up for the contest here. Top 10 winners will receive a HackerRank T-Shirt. The contest is rated for all users.

HourRank 7 problem set is prepared by me (ma5termind) and is tested by svanidz1. I would like to thank Shafaet for helping us preparing this round.

I am sure that everyone will find this round interesting and challenging. Each problem will be starring my friend Nikita and you have to help her solving some simple but interesting tasks.

Hope to see you participating.

Good Luck & Have Fun

UPDATE 1: Score Distribution: 25 50 70 80. Contest will be stated in less than 2.0 hour.

UPDATE 2: Contest will be stated in less than 20 minutes.

UPDATE 3: Timer begins 60 minutes 4 problems. All The Best :) :)

UPDATE 4: Thank you for participating. Contest has ended. Editorials are published.

Top 10 on the leaderboard
Errichto
anta
mgch
sokian
Vercingetorix
I_love_Tanya_Romanova
rajat1603
savinov
djdolls
zemen

I hope you have enjoyed the contest. Please feel free to provide your feedback in comments.

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

Auto comment: topic has been updated by ma5termind (previous revision, new revision, compare).

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

Auto comment: topic has been updated by ma5termind (previous revision, new revision, compare).

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

Auto comment: topic has been updated by ma5termind (previous revision, new revision, compare).

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

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

Hackerrank.com takes much time to respond , does anyone else face the same problem ?

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

Problem #2:

Nikita must partition the array into 2 non-empty parts

Am I the only one, who didn't understand, that the resulting parts should be SUBARRAYS?
Was trying to solve a problem splitting in subsets and didn't have any idea even for the easiest subproblem..

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

    Nope.That's how I understood it too.Spent 20 minutes wondering how are so many people doing this?

    Sample test cases also supported both the approaches simultaneously.

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

    Well, first I thought the same, but I realized that is too hard to be second task and also I think we wouldn't call parts 'left' and 'right' if they aren't subarrays :P

    I like first three tasks, I think they were on good level for one hour contest. I will read the fourth when I solve third for full score :P

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

    Hi DmitriyH,

    In each move, Nikita must partition the array into 2 non-empty parts such that the sum of the elements in the left partition is equal to the sum of the elements in the right partition. If Nikita can make such a move, she gets 11 point; otherwise, the game ends. __

    I personally don't think that it was confusing as many other participants have solved it. There is nothing called left partition and right partition if we meant to partition it into subsets.

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

      Maybe "split" would be a better word? (better than a verb "partition")

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

        That could be better but I think one shouldn't think about subsets after seeing "left partition" and "right partition".

        Also it was clear from the figures in explanation too, see how the curly brace was used. And its written that "she splits the array into 2 partitions having equal sums."

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

      Thanks! My bad :)

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9 years ago, # |
← Rev. 2   Vote: I like it +46 Vote: I do not like it
  • fine A
  • very cool but maybe a bit hard B (slightly harder than B should be in this contest, in my opinion)
  • fine C (but I don't know how people solved it so quickly — took me a lot of time and after that I was struggling with overflows for extra 5-10 minutes)
  • very cool D (I had enough time only to write a brute force but will definitely upsolve it)
  • in D in constraints you shouldn't say what is required in the output. Instead, in Constraints or Output (or in many places) you should say that it's guaranteed that at least one solution exists.

Nice contest. Next time I will likely participate again after seeing you as a setter.

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

    Thank you errichto. I am glad to have nice words from you :).

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

The tasks were really interesting and enjoyable...

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