5. (6 points) Divide-and-Conquer. Given an array A[1...n) consisting of n numbers (each number could be positive or negative). In this problem, you are going to find a consecutive segment of A that sums up to 0 using divide-and-conquer. The straightforward approach to solve this problem is to enumerate all possible starting and ending indices of the segment and test if it sums up to 0. However, it takes O(na) time, which is not ideal. (a) First, you will develop the combine step of the divide-and-conquer algorithm, zero(X[1 ...k], Y[1...l]). zero(X[1 ...k], Y[1 ...1]) determines if there exists 1