Pols_Agyi_Pols's blog

Invitation to CodeChef Starters 98 (Rated till 6 Stars ) — 12th July
By Pols_Agyi_Pols, 17 months ago, In English

We invite you to participate in CodeChef’s Starters 98, this Wednesday, 12th July, rated till 6-stars Coders (ie. for users with rating < 2500).

Time: 8:00 PM — 10:30 PM IST

Note that the duration is 2.5 hours. Read about the recent CodeChef changes here.

Joining us on the problem setting panel are:

Special Thanks to Anshiv sv1shan Singla and Hriday the_hyp0cr1t3 for their valuable feedback.

Written editorials will be available for all on discuss.codechef.com. Pro users can find the editorials directly on the problem pages after the contest.

The video editorials of the problems will be available for all users for 1 day as soon as the contest ends, after which they will be available only to Pro users.

Also, if you have some original and engaging problem ideas, and you’re interested in them being used in CodeChef's contests, you can share them here.

Hope to see you participating.
Good Luck!

UPD: Editorial is out.

  • Vote: I like it
  • +118
  • Vote: I do not like it

Comments Comments (26)
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17 months ago, # |
  Vote: I like it +30 Vote: I do not like it

orz

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17 months ago, # |
  Vote: I like it +25 Vote: I do not like it

orz

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17 months ago, # |
  Vote: I like it +16 Vote: I do not like it

orz

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17 months ago, # |
  Vote: I like it +18 Vote: I do not like it

orz

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17 months ago, # |
  Vote: I like it +21 Vote: I do not like it

cant wait for this contest

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17 months ago, # |
  Vote: I like it +8 Vote: I do not like it

Thank you, like your regular contests.

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17 months ago, # |
  Vote: I like it +16 Vote: I do not like it

Very nice contest, thank you again.

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17 months ago, # |
  Vote: I like it +5 Vote: I do not like it

Didn't manage to solve div.2 D,E or F, but solved G by accident...

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17 months ago, # |
  Vote: I like it 0 Vote: I do not like it

What's the intended solution for HOSTEL? Also should have been a 3 hour contest

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17 months ago, # |
  Vote: I like it +43 Vote: I do not like it

Thanks all for your participation. Since this was my first contest your feedback would be valuable.

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    17 months ago, # ^ |
      Vote: I like it +11 Vote: I do not like it

    Actually, SMQRY can be solved in $$$O(q\log n)$$$ with Link-Cut Tree.

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      17 months ago, # ^ |
        Vote: I like it +21 Vote: I do not like it

      Amazing ! Thanks for pointing out. I am sorry for having no idea of that thing previously but will definitely try to explore about it now.

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17 months ago, # |
  Vote: I like it +42 Vote: I do not like it

orz problemset, could've been a 7* contest too. Loved participating

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17 months ago, # |
  Vote: I like it 0 Vote: I do not like it

How to solve Div2 B Problem Ball Distribution. I thought of binary search but not able to get AC :(

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    17 months ago, # ^ |
    ← Rev. 3   Vote: I like it +5 Vote: I do not like it

    You can divide the boxes into 2 types.
    1: which contains ball of all colors
    2: which has at least one color missing
    Assume initially we have all boxes of type 1.
    Now iterate on each colors, and think how can you minimize type 1 boxes.

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17 months ago, # |
  Vote: I like it +29 Vote: I do not like it

Problems E and F are nice, D was annoying though (subarray sum)

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17 months ago, # |
← Rev. 3   Vote: I like it 0 Vote: I do not like it

In the problem BUILDT (https://www.codechef.com/START98A/problems/BUILDT ), it is not clear to me whether the towers are distinct or not. Additionally, all $$$a_i$$$ in the sample cases are $$$1$$$ or $$$0$$$. Therefore, I was wrong on almost all testcases except the ones with $$$\max a_i \leq 1$$$.

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    17 months ago, # ^ |
      Vote: I like it +16 Vote: I do not like it

    u can consider each tower distinct based on node U and which rank is this tower in creation order T, for each node U now there are few thinks u have to take care of

    for creation order of tower i and tower j, if Ti < Tj, tower i should be placed before tower j

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      17 months ago, # ^ |
      ← Rev. 3   Vote: I like it 0 Vote: I do not like it

      Yes, I got three WAs because I didn't divide $$$a_i!$$$, I treat them as distinct towers. From the editorial, It seems that the only mistake I made was that I should divide $$$a_i!$$$ as towels are identical.

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        17 months ago, # ^ |
          Vote: I like it +16 Vote: I do not like it

        they should be treated differently imo, but u can't create tower x + 1 before creates x towers

        thats why factorial doesn't make sense because u can't order them

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