For given input, editorial solution will not work.

A : [ 0, 1, 1, 2 ]

B : [ 0, 1, 2, 2 ]

As per the max(X,Y) logic, it is returning 3. But expected value is 2.

Given three points are: (0, 0), (1, 1), (1, 2) and (2,2).

It takes 1 step to move from (0, 0) to (1, 1). It takes one more step to move from (1, 1) to (2, 2).