Morphy's blog

CodeChef January Long Challenge 2020
By Morphy, history, 5 years ago, In English

Codechef January Long Challenge starts in less than 24h.

I challenge top coders to AC everything in less than 5h.

See you in the ranklist!

  • Vote: I like it
  • +70
  • Vote: I do not like it

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

do you mean January long challenge? :x

→ Reply
»
5 years ago, # |
  Vote: I like it +40 Vote: I do not like it

What is Taster? O_O

→ Reply
  • »
    »
    5 years ago, # ^ |
      Vote: I like it +21 Vote: I do not like it

    according to google translate: "a person employed to test food or drink (or problems) for quality by tasting it"

    → Reply
  • »
    »
    5 years ago, # ^ |
      Vote: I like it +38 Vote: I do not like it

    You get to taste the problemset first, I suppose. Yummy-yum.

    → Reply
»
5 years ago, # |
  Vote: I like it 0 Vote: I do not like it

How can I register?

→ Reply
»
5 years ago, # |
  Vote: I like it +15 Vote: I do not like it

I challenge top coders to AC everything in less than 5h.

(including both challenge problems)

→ Reply
  • »
    »
    5 years ago, # ^ |
      Vote: I like it +8 Vote: I do not like it

    To clarify — in the challenge problems, even a 0 score counts as AC, correct? (Since it is relative scoring)

    → Reply
    • »
      »
      »
      5 years ago, # ^ |
      ← Rev. 2   Vote: I like it 0 Vote: I do not like it

      There's an AC verdict and a WA verdict, which is independent of score. It's pretty damn hard to get so few points that they'd be rounded to 0 though.

      That wouldn't be much of a challenge though.

      → Reply
»
5 years ago, # |
  Vote: I like it +4 Vote: I do not like it

How to solve ARMYOFME?

→ Reply
»
5 years ago, # |
  Vote: I like it +3 Vote: I do not like it

How to solve ENGLISH?

→ Reply
»
5 years ago, # |
  Vote: I like it 0 Vote: I do not like it

What was the intended complexity for the solution to ENGLISH?

I saw solutions of order $$$O(n * (n + 1) / 2 * maxlen)$$$ that passed with a few optimizations

→ Reply
  • »
    »
    5 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it
    $$$\mathcal{O}(input)$$$
    → Reply
  • »
    »
    5 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    Yeah, I saw some solutions using trie which I think was intended and is fast enough but some solutions seemed to be using brute force with complexity same as what you wrote. Can anyone explain the solution to this question in detail please?

    → Reply
    • »
      »
      »
      5 years ago, # ^ |
      ← Rev. 2   Vote: I like it 0 Vote: I do not like it

      BRIEF EXPLANATION

      You are given N words and the beauty of a pair of words (w1, w2) is computed as min(length of the common prefix between w1 and w2, length of the common suffix between w1 and w2) ^ 2.

      Find a way to pair the N words such that the total beauty of all the pairs is maximum and it's ok not to pair a word at all.

      Hope this helps.

      → Reply
»
5 years ago, # |
  Vote: I like it +21 Vote: I do not like it

Congrats to the winners!

Div 1.

  1. cheng2014
  2. tmwilliamlin168 (He moved to the top of the scoreboard in the last day!)
  3. WHITE2302
  4. yashChandnani
  5. wrong_answer_1
  6. zhouyuyang
  7. savinov (highest score in CHEFARMY)

Div 2.

  1. cskanani
  2. icecuber
  3. tomas5
  4. amansonkar
  5. flynn_ryder
  6. hawasi_69
  7. AkJn
→ Reply
»
5 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

Are codechef long challenge div1 problems similar to ICPC problems? Or are the made to be more time consuming?

→ Reply
  • »
    »
    5 years ago, # ^ |
      Vote: I like it +6 Vote: I do not like it

    I noticed some legends like ACRush solve everything in ~8h. When we have superhard problems it is solved in 2 or even 4 days.

    The main difference with ICPC (other than partial scoring) is the tie-break problem, in which contestants spend a lot of time (in some problems the winner wrote more than 2^11 lines of code!).

    → Reply
    • »
      »
      »
      5 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Is there a resource for problems similar to challenge problems? Or any resources to learn how to solve them better?

      → Reply
      • »
        »
        »
        »
        5 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        CodeChef has some editorials. Unfortunately sometimes the editorialist is not well versed in approximate problems and we end up without editorial.

        Also you can see topcoder marathon matches.

        → Reply