Invitation for January Cook Off, 2018

After the recently concluded January Long Challenge, I would like to invite you for some more interesting challenges to keep your coding schedule always packed! Participate in the January Cook-Off 2018 and enjoy Chef’s tricky tests.

Joining me on the panel are:

  • Problem Setter and Editorialist: Sidhant Bansal, Arjun Arul
  • Problem Tester and Admin: Hasan Jaddouh, Misha Chorniy
  • Russian Translator: Sergey Kulik
  • Mandarin Translator: Hu Zecong
  • Vietnamese Translator: VNOI Team

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

Contest Details:

Time: 21st January 2018 (2130 hrs - 0000 hrs Indian Standard Time — +5:30 GMT) — Check your timezone.
Contest link:
Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.
Prizes: Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: (For those who have not yet got their previous winning, please send an email to

According to me, the problems are very interesting and I am sure that you will have fun while solving these problems :slight_smile:

Good Luck! Hope to see you participating!!


Thank you @admin :slight_smile:

PS — In this cook off, we have changed the penalty from 20 minutes to 10 minutes. Enjoy!!


Reducing the penalty time is a good step from your side as 20 minutes is too harsh for a short contest of 2.5 Hrs.

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Great step…

Thanks a lot @admin


In the recently concluded COOK90, there were weak test cases for the SURVIVE problem. This was brought to my attention by (preda2or). The below test case was mentioned by him in another thread.


9 8 10

By the end of saturday(6th day you will have 6 chocolates with you and and won’t be able to survive). So expected output is -1 but many submissions give 9 as output.

I had to spend a few more minutes checking for all corner cases and coding it up correctly. As this is the easiest problem in the contest, it is sure to make a difference in the ranks of people. So I request admins to look into this issue and make sure that it doesn’t creep up in future contests. Thank You.

I am also attaching links to a few submission which give WA.

s6 These are only from the first page. @admin


Yeah I also wasted a lot of time and seeing the submissions number I thought myself leaving Competitive Programming because spending many months on it and not able to solve “EASY(by number of submissions)” Question(But now I am happy that my code gives correct answer for above case :slight_smile: ) .Anyways I hope @admin takes a wise decision.



8 7 9
This is just another test case where different solutions give different answers :stuck_out_tongue:


@admin Can you tell us what are your steps taken to handle the issue of weak test cases in problem SURVIVE?

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When will the editorial for problem MAGA be up ?


We will add test cases to break these solutions in practice session. However, according to our policy, we don’t retrospectively rejudge the problems. So, the standings of the cook-off stay as it is.


looking for the same

Very good policy indeed.

1 Like