What is the problem in this code??

Question

I tried to solve the N queen problem but it's not a working as I wanted. There is no error in this code but it's planning the queen only one. But I want to place queen 4 times. Is here anyone to figure out what's wrong with my code??
https://code.sololearn.com/c9NzfeL141Xb/?ref=app

Answer 1

Plz review my code again. I am not getting what's wrong here is going.