Ericsson Interview Question

1st and 2nd round they asked coding questions. First round is coding, second is system design 3rd is cultural and behavior round. In 2nd round interviewer was not ready with questions. He asks to implement binary search. Then asks me to add code to build the tree. Next asked to delete a node things like that. It felt that he was just wanted to kill time. In 3rd round he asked me what do I do after my work. Twice. same question two times.