If anyone can share a good resource for learning Policy Based Data Structures (PBDS) of STL. I tried searching about them and found some videos but if someone has good articles that explain them in detail, please do share. Thanks!

I was solving this problem, this was the code that I wrote initially in which I used vector for dp (CODE), but when I replaced it with a global array of the same size it got AC (Updated Code), Can anyone please explain what is the problem with using vector here, or an article which explains this would be helpful.

Thnaks!