commonTwo

Start with two arrays of strings, a and b, each in alphabetical order, possibly with duplicates. Return the count of the number of strings which appear in both arrays. The best "linear" solution makes a single pass over both arrays, taking advantage of the fact that they are in alphabetical order.
commonTwo(["a", "c", "x"], ["b", "c", "d", "x"]) → 2
commonTwo(["a", "c", "x"], ["a", "b", "c", "x", "z"]) → 3
commonTwo(["a", "b", "c"], ["a", "b", "c"]) → 3

Solution:

public int commonTwo(String[] a, String[] b) {
 int c = 0;
 String last = "";
 for(int i= 0; i