Is it a good idea to this or will managers look down on this?
I wouldn’t. I doubt it will get you an interview, and if the interviewer sees you flexing your LC, they might give you harder questions.
RIP JK. They may think that you are gaming the system if LC/HackerRank are there. You can sign up for a dummy GitHub handle to store the answers and tests tho.
Big red flag
You will directly get hired based on rank
Seriously though, does it look good or bad
Bad . It’s like saying you solved 21 questions before your exams. No one cares and it looks bad