What's the issue with this code?

what’s the possible issue in this code when I submitted this code it cases failed test case 2
and when I opened the input added in that test case it was 1 -11 28
and the result was same as were mine I can’t understand what made this code failed…
I also checked the answer key there was a use of discriminant I don’t think that would be the cause of this error, please help

your output should be in this format

.The next line contains roots(in non-decreasing order) separated by a space if they exist.

you can refer my code as well

I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.

On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.