crap_the_coder's blog

Invitation to D'Code 2023 from Amalthea, IIT Gandhinagar
By crap_the_coder, history, 6 months ago, In English

Hello everyone! Hope you're all doing well.

Guess what? The next edition of D'Code by IIT Gandhinagar is here!

We have 6 algorithmic problems prepared for you to put your mind to test your problem solving skills.
The contest starts today at 9 PM IST and has a duration of 2 hours. Link of the contest: https://www.codechef.com/DCDE2023

Need an incentive? We've got you covered. There are exciting prizes worth ₹26,000 for the top performers!
NOTE: You need to register here, to be eligible for prizes.

Setters/Testers: mshandilya, crap_the_coder, nishuz, Karan-Gandhi, dewansh461.

Good luck for the contest and we hope you all have fun! :D

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6 months ago, # |
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Auto comment: topic has been updated by crap_the_coder (previous revision, new revision, compare).

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6 months ago, # |
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problems not loading

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    6 months ago, # ^ |
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    I got problem links from standings

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    6 months ago, # ^ |
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    No idea what happened. There seems to have been an issue with CodeChef, but it should be fixed now.

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6 months ago, # |
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Clashes with Meta Hacker cup. Pls reschedule.

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    6 months ago, # ^ |
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    Due to the technical summit events in our college, we couldn't have it at a different time. Sorry about the clash :(

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6 months ago, # |
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Status: Wrong Answer Submission ID: 1028653819 Memory: 3.7M Sub-Task Task # Result (time) 1 0 Correct (0.00) Subtask Score: 100% Result — Correct Total Score = 100%

Sorry, i am not familiar with the platform. Total Score is 100% while Wrong Answer! How does it work?

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    6 months ago, # ^ |
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    Hey, sorry. We are trying to figure this out, but the verdict will be "Correct" if your code is correct.

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      6 months ago, # ^ |
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      This happens with me also

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      6 months ago, # ^ |
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      Hi how to submit after the contest. It is not accepting solutions, and problems are neither in practise.

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6 months ago, # |
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bruh wtf is the time limit for D ??

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6 months ago, # |
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nishuz orz

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6 months ago, # |
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Is there a mistake with this idea for Trade Center? Or is it just a mistake in my implementation?

  • Goods from city $$$x$$$ will always travel on the shortest path from $$$x$$$ to $$$t$$$.

  • The shortest path routes represent a tree rooted at $$$t$$$ (since it is "guaranteed that there exists exactly one cheapest path between the Trade Center and any other node")

  • Query 1 is equivalent to $$$w_{u} \cdot dist_{u}$$$.

  • Query 2 is equivalent to $$$\sum_{x \in subtree_{u}} {w_{x}}$$$ in this new tree.

  • Query 3 is equivalent to $$$lca(a, b)$$$ in this new tree.

Query $$$1, 2, 4$$$ can be handled by using any point update, range sum query data structure on the dfs order of the tree since $$$subtree_{x}$$$ represents a contigious range $$$[in_{x}, out_{x}]$$$ in the dfs order. LCA can be calculated normally by your choice of implementation.

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    6 months ago, # ^ |
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    Yes, your solution is correct; there might be a bug in the implementation.

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6 months ago, # |
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IS PROBLEM A HAS SUBTASK 2 MY CODE PASS IN SUBTASK 1 BUT STILL GIVES WRONG ANSWER

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6 months ago, # |
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Posting announcement 3 hours before the contest? Do you think people live on CF or what?

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6 months ago, # |
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How to solve break stick? I used gnu pbds but it gave me TLE.

Also where can the editorial be found?

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    6 months ago, # ^ |
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    Gnu pbds has high constant factor. Here, Use Fenwick tree, it is very fast.

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      6 months ago, # ^ |
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      Hi can i use lazy segment tree? for range updates

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        6 months ago, # ^ |
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        Why do you want to range update? Just do point update and range query

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          6 months ago, # ^ |
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          say if i am breaking about point b[i], then add 1 in [b[i]+1, N]. then do query for value at c[i]. That's my idea.

          Edit : I get you. You will add one to point b[i]+1 and you will query in sum[0, c[i]-1]. Right?

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      6 months ago, # ^ |
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      https://www.codechef.com/viewsolution/1028659335 ???

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        6 months ago, # ^ |
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        I don't have access to your submission. My ordered set soln was also giving TLE.

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          6 months ago, # ^ |
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          I tried this after failing with seg tree and ordered set and still got TLE

          code
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            6 months ago, # ^ |
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            Where are you submitting your code? The problems are not available for submit for practice for me.

            My AC code
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