PubMatic Interview Question

1>Reverse the any two node in linked list 2>internal implementation of HasMap. 3>difference between array and arraylist. 4>one sql query using join 5>collections questions in deep 6> way of creation of thread and one program 7>algo to create the the binary tree 8>basic question related hiberanate and spring 9>what will happen when we insert null in hashmap 10>custom sorting of student class object