This is an Algorithms question. Thank you.

Suppose we are given two n-element sorted sequences A and B that should not be viewed as sets (that is, A and B may contain duplicate entries). (a) Describe an O(n)-time algorithm^2 for computing a sequence representing the set A Intersection B. (b) If the sequences A and B are instead unsorted, what is asymptotic time complexity of the most efficient algorithm that you can construct that computes A Intersection B? Describe this algorithm