Video Editorials: *September Challenge*

Hey guys,

This is me Rachit Jain.
I had made a playlist for the previous August Challenge, which you can see HERE.

I was busy with office work recently, hence the delay for the video editorials for the September Long Challenge 2017(and also my poor performance :confused: ).

Anyways, my interest and love for the 6th problem(which I missed by 50 points because of a single test case.) which is Weasel Does Xor on Tree motivated me to release the video today itself, highlighting -

  1. How to approach problems when you have no idea?
  2. How to go further into depths, analyzing the problem in hand when you are stuck? Losing hope doesn’t helps. Wait. Relax. Go deep.
  3. The beautiful pattern of the matrix <3 Math really amazes me and I love it!

I have launched the 1st video where I explain the solution journey.
Check it out here:
Part 1: does XOR on Tree - Part 1)
Part 2: does XOR on Tree - Part 2)

I will probably release video for 5th problem: Fill the Matrix tomorrow.

UPDATE: New Video is out.
Check it here: [Tutorial] Codechef SEPT17 Long Challenge - FILLMTR | Union Find | Bipartite Graphs

Feedbacks are most welcome.
Thanks for reading.


The editorial of sumcube is still beyond my reach.
I would be very thankful if you can make a video for sumcube as well.


Hey, I have not solved that myself yet. But I will look into it later definitely.

1 Like

Dude do something with ur audio ;/
i can’t able to hear it anyway .

any editorials for the first 3 4 problems , I guess here forum ignores beginners

I guess you are slamming the beginners by just posting editorials for tougher questions , it would be better if you post for beginners as well , that will help them immensely , as at the starting what they need is proper explanation.

It would be great, if u make videos on Segmented trees, lazy propagation and binary indexed tree and pls give emphasis on problem solving, i mean how to implement them and solve problems, its kind of tough for beginners, and i like the way u make us understand.

yeah the sqrt decomposition part is difficult. a video tutorial on that part will be nice