please help me with second question, 7. Programming language: Java

6.[10] Write a method max() that takes a reference to the first node in a linked list as argument and returns the value of the maximum key (item) in the list. Assume that all keys are positive integers and returned 0 if the list is empty. 7.[10] Redo solution to question 6, but use an array (circular buffer), instead of pointers, to implement the list