A substring B of a sequence A is any consecutive set of values in A. For example, if A = [1, 7, 2, 4, 9, 0, 6] then possible substrings are [7, 2, 4], [0] and [2, 4, 9, 0, 6]. The sequences [1, 2, 7], [1, 7, 4], and [8] are not substrings of A. What is a numSubstring(int [] a, int [] b) method which returns the number of times b appears as a substring of a? For example, if a = [1, 2, 1, 2, 1, 1, 1, 2] then the sequence [1,2] appears 3 times, the sequence [2,1] appears 2 times and the sequence [1,2,3] appears 0 times. I have been instructed that numSubstring should call a recursive method that uses a divide-and-conquer approach to solve this problem.