Suppose you are given an array A[1, n] of n numbers, which may be positive, negative, or zero. Write down an efficient algorithm that would return true if it finds a subarray A[i,j] that sum to 0. For example, A = [1, 2, 3, 1, 2] has a subarray A[2, 4] that sum to 0. Analyze the complexity of your algorithm.