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abhi2402's blog

By abhi2402, history, 4 years ago, In English

Hello Codeforces!!

I, on behalf of Code Chronicles 1.0 Team, would like to invite you to take part in first ever contest hosted by collaboration of IIIT's (IIIT Pune & IIIT Bhopal), which will take place on Friday, June 19, 2020 at 20:00 ISTUTC+5.5. It is a 2.5 hr long contest. The contest will be open to everyone. We'd be offering you 8 problems with varying difficulties.

PRIZES : 250 Codechef Laddus each to Top 3 Global & Special Goodies for Top 3 IIIT ians.

Contest Link : Code Chronicles 1.0

I would really like to thank:

I hope you will enjoy solving the problems. Please give your feedback on the problem set in the comments below, after the contest.

Upd 1: Editorials have been published for all problems except PWCP-COCR101, which will be published by tomorrow.

Upd 2: Editorial for PWCP has been published. You can check it out below.

Upd 3: Prizes (250 Laddus) have been credited. Congratulations to the winners!

  1. uwi
  2. Egor
  3. BohdanPastuschak

Top IIIT ians :

  1. aneesh2312
  2. sudoBug
  3. agrawal117

Editorials :
Marking the borders-COCR104
Champak and Clocks-COCR105
Sharing is Caring-COCR106
Chef and a New Home-COCR103
Odd One Out-COCR107
Time Travel-COCR102
Maze Runner-COCR108
PWCP-COCR101

About the discrepency in Marking the borders question :

There was a discrepancy in one of the input files for the question, Marking the borders. There was a single line missing in the input file. Even then many participants got accepted, but some received WA or TLE. It was a bit surprising about how had it not come up during the testing phase, but after reviewing a couple of solutions which didn't get accepted because of this, we observed that codes using $$$scanf$$$ were getting affected. Unfortunately even though all testers had tested this question, everyone used $$$cin$$$ / $$$cout$$$. We still don't know for sure that if $$$scanf$$$ / $$$cin$$$ thing was the only difference that lead to such a result. Sorry for the inconvenience caused due to this.

We still hope that you enjoyed the problemset though, and thank you for participating!!

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4 years ago, # |
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Deleted

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The contest begins in less than 10 minutes!

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4 years ago, # |
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I am eager to know the solution to the problem Odd one out, i tried using bitset + BIT using xor like think but it was giving TLE .

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    4 years ago, # ^ |
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    Segment Tree and bitset gave AC for 0.5 second :-0

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    4 years ago, # ^ |
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    Well, I solved it using your approach but included few pragmas to speed it up significantly!

    Code
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    4 years ago, # ^ |
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    The idea was to use bitset and segment trees. However I think BIT + bitset should also work fine with small optimizations. You can have a look at the editorial to get a better idea. https://discuss.codechef.com/t/editorial-odd-one-out-cocr107/69314

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      4 years ago, # ^ |
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      Yeah BIT + biset works fine without any optimization, but my solution was stupid that's why i was getting TLE. Now it works fine in just 0.24. Thanks to you and YouKn0wWho for his nice & clean solution.

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Cool problems! How to solve Maze Runner?

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    4 years ago, # ^ |
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    I tried using meet in the middle but got TLE, btw nice problems!

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      4 years ago, # ^ |
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      Your comment has both the key points necessary to solve this question. Meet in The Middle + Trie. xD abhi2402 the Comment section needs you!

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      4 years ago, # ^ |
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      It was indeed meet-in-the-middle + Trie.

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    4 years ago, # ^ |
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    I thought of using meet in the middle approach with tries to count ways but it was too much to implement :(

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    4 years ago, # ^ |
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    I solved it using meet in the middle and binary search to find the possible combinations.

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    4 years ago, # ^ |
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    meet in the middle
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Please unlock solutions

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    4 years ago, # ^ |
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    Yes, I have made the solutions public, it will take some time to reflect on the website.

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The editorial for Maze Runner(COCR108) is out. Link

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Please enable the submit button of each question.

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    4 years ago, # ^ |
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    We have asked Codechef to move the questions to practice section as soon as possible. Although it may take some time to actually reflect on the website. Thankyou for your patience.

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    4 years ago, # ^ |
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    UPD: All problems have been moved to practice section. You can submit them now.

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Auto comment: topic has been updated by abhi2402 (previous revision, new revision, compare).

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4 years ago, # |
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Auto comment: topic has been updated by abhi2402 (previous revision, new revision, compare).

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4 years ago, # |
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scanf/cin was not a problem imo, because my solution got WA with cin.

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Auto comment: topic has been updated by darshancool25 (previous revision, new revision, compare).

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4 years ago, # |
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Auto comment: topic has been updated by darshancool25 (previous revision, new revision, compare).