shashank21j's blog

101 Hack July'14 — HackerRank
By shashank21j, 10 years ago, In English

Hello Coders!

The July edition of 101 Hack is here. 5 interesting challenges in 2 hours. The contest commences on on 26th July 2014 at 13:00 UTC, You can sign up for the contest here.

The problem statements will be available in English, Russian and Chinese.
Top 10 on leaderboard get cool HackerRank T Shirts
Books for individual challenge-leaderboard toppers

Problem Setters
Gerald

Problem Tester
Bidhan

Please try all problems, Editorials will be available at the end of contest.

GL&HF

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Comments Comments (17)
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10 years ago, # |
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What's is sorting order on HackerRank (in particular on 101 Hack)?

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    10 years ago, # ^ |
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    You mean, sorting order of problems?

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      10 years ago, # ^ |
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      No, I mean sorting order of participants in the leaderboard (Well, first thing is surely points, and then something else (or random?))

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        10 years ago, # ^ |
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        For same score tie breaking is done on Sum(time_of_submit)
        Like cumulative sum
        so challenge 1 got AC at 130th second, Challenge 2 got AC at 400th second. Total penalty is 530 seconds.

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          10 years ago, # ^ |
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          So, basicly as in ACM but without penalty time?

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          10 years ago, # ^ |
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          Is the same holds for standing for each challange?

          here there's label "1 hour ago" when hover me and "44 minutes ago" for person before me. But he is above me somehow.

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10 years ago, # |
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If I just read the statement, will my rating change?

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10 years ago, # |
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Any idea for Xor and sum?

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    10 years ago, # ^ |
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    Let's solve it bit by bit. It's easy to see that on bits with number BIG = 314159 + max(a.len(), b.len()) +-1 and greater the xor'ands are always 0.

    So for each bit we should calculate how many times it's 1. a[bit] is fixed and (b << i)[bit] are b[i], b[i — 1], b[i-314159]. With prefix sums you may understand how many times the last one is 1. So multiply it or (314159 + 1- it) by 2^bit (precalculated for all bits up to BIG)

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10 years ago, # |
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Sorry, but what is default stack limit for C++ solutions? Or where can I found information about it?

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