Invitation to CodeChef April Long Challenge 2018!

Hello Fellow Coders!

Greetings from Chef! Close on the heels of an exciting lineup of contests you all enjoyed, here’s more from Chefland to satisfy your coding appetites in April. This time it’s not a quick snack, it’s a full-course meal with ten days prep time!

I would like to invite you to the April Long Challenge 2018 for 10 days of exciting programming challenges. Joining me on the problem setting panel are:

Please give your feedback on the problem set in the comments below, after the contest.

Contest Details:

Time: 6th April 2018 (1500 hrs) to 16th April 2018 (1500 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 global and top 20 Indian winners get 300 Laddus each, 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 !!


As an additional reminder-

Kindly discuss any issues, clarifications etc. related to problem/problem-statements at COMMENTS section of the problem with the setting panel. Any feedback related to this long should be posted here only - the use of separate threads should be avoided as it makes collecting feedback a mess.

Any instance of your code getting public due to online ides like is punishable, and you will be penalized with same punishment as that of any regular plagiarist.

If possible , the challenge should be extended just for a day .As we are having Google code jam today.

Duration of APRIL18 will be extended by one day soon.

It really shouldn’t matter. GCJ was just for 27 hours.

Yes, but we extended APRIL18A from another reason - JADUGAR

1 Like

For 300 laddus rank should be in top-20(Indians) in Division-1 or top-20 in both divisions combined ?

Div1 afaik. The page there says nothing about div2 top 20. It would be unfair for newly gone div1 guys if they’d get equal prize in div2. Would be undesirable.

why duration of APRIL18 long challenge of div-B is not extended while for div-A it is already extended?
@mgch @vijju123

Div1 got extension because the problem JADUGAR was split into two, and a new subproblem was added in the newer version, JADUGAR2. This did not affect div2 in any way.

However, if you want an extension as well, I can talk to @mgch regarding that- but I need a valid reason to do so.

Because code jam take almost one full day.So many participant cant try problem through out whole day…if you kindly extend it…it will be better…@vijju123

I will consult contest admin @mgch over your concern.

The contest for Div2 is extended now. It will end on Tuesday with Div1.

thank you @vijju123

when will the editorials get uploaded.

They already are.

@admin @mgch . I was seeing all submissions page Just after the contest was over. There were submission which were still processing after 3.30 pm. Big queue was there on system. At around 5-6 am. System was taking about 3-4 min to process the result.

One suggestion Please don’t make the challenge problem such that anyone can atleast get AC. For this contest challenge problem Submissions which simply print A[i]. No processing. Or which print A[i]+k . Were awarded around ~80-90 points. This was the main reason for Big Queue.

1 Like

I already replied to your query. I will copy it here for documentation purposes :slight_smile: -

@aryanc403- Thats not correct, and wont help. One instance I can give is, that today itself, some guy submitted ≈60 submissions on PyPy, each of which took 20secs to get verdict.

A better solution which we suggested what “Limit number of submissions a user can make in X minutes to Y”- i.e. dont allow indefinite submissions for any problem.

So with this we conclude our April Long Challenge, 2018.

We hoped you enjoyed the problems, and will enjoy the editorials as well. Any feedback on problems, editorials, or any other issue is appreciated. We will try our best to improve upon those areas :slight_smile:

If theres anything we can do for you, do let us know. Its been a pleasurable experience for me on the other side of the panel (thanks to the team and @mgch ) and I hope I can say the same for you guys as well :).


Yes, this is nice idea. Time duration constraint is okay. Currently we can submit 500 submissions in long challenge. Please don’t reduce this limit. One more suggestion this limit can also be on basis of language used. Because PyPy take around 20 sec. So X can be less for PyPy. And C takes less time So X can be greater for C.