I want to study plus code data structure from basic, which online class ( free) or website is best for it?

Answer 1

You can find some of that on SoloLearn itself 🙃

Answer 2

I would look at the top results from a web search.

Answer 3

I don't know if it is the best but you can use geeksforgeeks
https://www.geeksforgeeks.org/data-structures/
I prefer using it coz it's really wide

Answer 4

Sololearn 😉