Invitation to CodeChef September Lunchtime 2018!

Hello CodeChef Community!

We would like to invite you to our next monthly contest and we’re sure you’ll enjoy - the September Lunchtime 2018 sponsored by Sharechat! Get ready for a three-hour test of your coding brains and pit yourself against the best. And there’s more! We have exciting full-time job opportunities by ShareChat for professionals across the globe. More details can be found on the September Lunchtime contest page.
Joining me this time on the problem setting panel are:

  • Problem Setter: kingofnumbers (Hasan Jaddouh)
  • Problem Tester: teja349 (Teja Vardhan Reddy)
  • Editorialist: taran_1407 (taran_1407)
  • Statement Verifier: xellos0 (Jakub Safin)
  • Russian Translator: gomelfk (Fedor Korobeinikov)
  • Mandarin Translator: huzecong (Hu Zecong)
  • Hindi Translator: srijand (Srijan Dubey)
    -Bengali Translator: solaimanope (Mohammad Solaiman)
    -Vietnamese Translator: VNOI Team

Contest Details:

Time: 29th September 2018 (1930 hrs - 2230 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.

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

Good Luck!

Hope to see you participating!

Happy Programming!

I am thinking about hosting a twitch stream soon after the contest to discuss the tasks from the contest.
What is your opinion on it.
Incase there is good response I will host a stream discussing problems.


Incase you feel stream will be helpful. Upvote this comment. so as to get some quantitative idea.


The editorials for first four problems are ready and will be available once admin moves them to public. Editorials for last two would be available within one day.

Hope you all had a great contest.

Problem Link

Can anyone please explain me why

This is giving WA BUT

Got me AC

The only difference is I used an “unordered map” in the second solution. I understand it improves the time complexity but there was still not an issue of that.

Problem Link

“Biased Judgement”

Why is this solution giving a complete 100 pt. ? Link to my practice solution

Why stream on Twitch ? AFAIK its designed specifically for streaming Games although normal streaming isn’t impossible, but still there maybe some issues. Why not live stream on YouTube instead ? And yes a live stream right after the contest would be a really good idea since we can atleast have a sound sleep having understood the problems which gave us a headache during the contest :stuck_out_tongue:

Identical solutions give WA and AC.

You WA solution gets AC if submitted in practice.

You are right @eugalt

I submitted in practice

This is giving AC.

@admin @teja349 @kingofnumbers please look into the matter. There is a serious problem with Codechef I believe. This problem is faced very often these days.


Thanks for reporting. We are looking into this issue and will get back to you soon.

Here is the link of the live stream.

let us all appreciate @teja349 for streaming.