Intersection Of Sorted Arrays

Find the intersection of two sorted arrays. OR in other words, Given 2 sorted arrays, find all the elements which occur in both the arrays.

Example :

Input : 
    A : [1 2 3 3 4 5 6]
    B : [3 3 5]

Output : [3 3 5]

Input : 
    A : [1 2 3 3 4 5 6]
    B : [3 5]

Output : [3 5]

NOTE : For the purpose of this problem ( as also conveyed by the sample case ), assume that elements that appear more than once in both arrays should be included multiple times in the final output.

public class Solution {
    public ArrayList<Integer> intersect(final List<Integer> A, final List<Integer> B) {
        ArrayList<Integer> ans = new ArrayList<>();
        int i = 0, j = 0;
        while (i < A.size() && j < B.size()) {
            if (A.get(i).compareTo(B.get(j)) == 0) {
                ans.add(A.get(i));
                i++;
                j++;
            } else if (A.get(i).compareTo(B.get(j)) < 0)
                i++;
            else 
                j++;
        }
        return ans;
    }
}