April Challenge 2017

Hi, everybody. This is a place where you can express your general feedback about the April Challenge that has just ended.

Regarding weak tests in DISHLIFE: read my answer here.

What do you think about problems, including their difficulty? My personal opinion is that easy problems should be a bit easier, and there should be one more very hard problem (instead of one medium-hard problem). Do you agree?


This was the very good long challenge and specially because it followed the difficulty of problems given here - (unlike what happens usually)

My personal view on problems -

  1. Cakewalk
  2. Simple
  3. Simple
  4. Easy
  5. Easy-Medium
  6. Easy-Medium
  7. Easy-Medium or Medium (difficult to say)
  8. Medium
  9. Tiebreaker
  10. Didn’t try so can’t say

In my opinion, this Challenge was an unusually easy one. The first 3 questions were alright, easy enough as they should be. But next came 4 easy-medium problems - CLIQUED, CHEFDIV, SMARKET, and RNDGRID, out of which in my opinion, 2 could have been discarded. Instead of them, 2 more medium-difficult problems would have made the contest a much more exciting one.

And yes, one very-hard problem (harder than HLD) would have been good - When the top 20 contestants all have 999 points, the deciding factor becomes luck rather than skill.


APRIL17 was really a nice contest…Contest is so much fun when @errichto is the problem setter!


please also add topic tags to the editorials of the problems.


The contest was really good. I enjoyed solving the problems. What I feel is one easy-medium problem could have been a medium-hard or hard problem. Otherwise, it was a nice problem set.

1 Like

Great contest, loved the fact that there was space even for Naive/Psuedo-Naive solutions. Made the contest much more interesting and even beiginners could attempt almost all problems and get some points.

1 Like

This Long contest was a good one to fetch many points, which helps in motivating one (especially beginners) to keep programming and learn new stuff. The Easy problems were really easy, and there was a lack of Medium/Medium-Hard problems. I liked how DGTCNT could be solved using Inclusion-Exclusion principle too (I am bad with DP :P)

Overall though, there was some inflation in the points scored by people, especially for the top rankers - top 32 above 990 points is unusual! Again that is because of the unequal distribution in difficulty level. But sometimes such Challenges are fun!

Thanks for a great Challenge!

1 Like

I think the gradient of the contest was very appropriate and uniform.All the questions were really interesting and fun to solve with a diverse variety of concepts involved as well such as segmented seive,merge sort tree,digit dp with inclusion/exclusion and tree dp.Great problem setting @errichto.

1 Like

I guess only an addition of a somewhat harder problem than the last question would have resulted in a usual leaderboard. Though there were too many easy-medium/medium problems but the concept and the constructive solution they had was worth a long challange.Also the fun quotient of the questions was good.

Problems were extremely good. The problems were easy compared to other long challenges. I would like to say it was more encouraging.

Agree with categorization

1 Like

The problems were conceptually strong. It required the person to be well versed in multiple concepts. I liked the DGTCNT and that stanle market ones the most. Also by giving that sort-based question, the peoblem setters stressed the vital point that “one must build his fundamentals and have his basic clear” . Because those who arent versed with the sorting algo wouldnt be able to solve the final sub task.

Weak test cases or not, the problems were decent concept wise and APRIL LONGs problems are the ones i recommend solving for practice as they check multiple concepts.


Why didn’t my solution work for Similar Dishes ?
Without \n at the end of the input the program seemed to be running continuously.

My solution : String contains method

Can anyone explain what went wrong?

Ya, errichto is a nice guy. I noticed a change in quality when he and other setters came in :slight_smile:

1 Like

That is how I feel too.

I wouldn’t say that scores for an approximation problem are based on luck more than on skills :wink:


I really liked the challenge.I am a beginner so able to do only first three problems.Can you provide the editorial soon.
Thank You.

1 Like

The editorials are out afaik.

Sorry i saw evening they were not there. I noticed now.Sorry for my mistake