Error coming while inserting in link list

Question

https://code.sololearn.com/cGvUG2BMW72m/?ref=app

Answer 1

I am not completely sure about the purpose of this statement(I have no experience using lambdas in java), but syntax using -> operator should be like this
" n1->{next=n;} " or " n1->next=n ".

Answer 2

yeeee