Problem 4. You are given two sorted arrays of integers A and B of size m and n, re spectively. Describe a divide and conquer that takes O(log k) time for computing the k-th smallest element in the union of the two arrays. Assume that integers in the both arrays are distinct, and no integers in A appear in B (and vice versa). Explain carefully why your algorithm takes O(log k) time. Hint: The k-th smallest element in the union of the two arrays has to be contained in A[1...k and B[1...k