Why i can't convert string to int in this code !! Some help please

Question

https://code.sololearn.com/cKGD2jQ9OIN1/?ref=app

Answer 1

Line 9:
String[] arr = str.split("");

Line 17:
list.add(i);

I think you may also need to check whether each String array <arr> element was a digit, otherwise you'd end up with conversion error(s) trying to convert non numeric String into an integer.

Answer 2

I added the trim() function in the input and it works fine
Thanks a lot