Consider the following problem where the input is an array of n numbers A[1...n] which could be positive or negative. We want to find the contiguous sub-array with the largest sum. For example, the contiguous sub-array of [-2,3,5,-1,9,-4] with the largest sum is [3,5,-1,9]. For simplicity, it suffices to output the just sum of such sub-array which is 16 in this case. A) Design a EREW PRAM algorithm that runs in O(log n) time and uses O(n) processors. Extra credit: improve the number of processors to O(n). B) Design an EREW PRAM algorithm that runs in O(log n) time and uses O(n) processors.