Is there any other source

I did not understood the from the function part and also I had to explore web for the explanation of “LCA”. As LCA is used this Lecture, I think that we should be given a brief knowledge about them.
Also, there is a VERY LOW VOLUME IN ALL LECTURES OF PERSISTENT S.T.
This is a problem because half of the time I have to figure out that what sir is saying.
I searched the web but didn’t got the particular “COT” spoj problem explained.
So, is there any other sources that can explain this concept in form of Lecture of animation

@Sparda947
I am sorry for the inconvience caused. I’ll tell the team about the issue.
There are some volume booster extensions for chrome/android etc . you can use that.
Video lecture : https://www.youtube.com/watch?v=TH9n_HVkjQM
A very good article with code : https://cp-algorithms.com/data_structures/segment_tree.html#toc-tgt-12

Okay I will look for the extensions you told me about