Implement the find maximum function recursively. Compare each element with the maximum of the rest.
Your function takes a list and returns its largest element.
Requirements:
- Base case: single-element list returns that element
- Recursive case: compare first element with max of remaining list
- Assume the list is non-empty
Examples:
find_max([3, 1, 4, 1, 5])->find_max([7])->find_max([-1, -5, -2])->
The pattern: max([3, 1, 4]) = max(3, max([1, 4])) = max(3, max(1, max([4]))) = max(3, max(1, 4)) = max(3, 4) = 4.