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Draw the recursion tree when n = 8, where n represents the length of the array, for the following recursive method: int sum (int[ array, int first, int last) if (first = last) return array[firstl; int mid = (first + last) / 2; return sum (array, first, mid) sum (array, mid 1, last) Determine a formula that counts the numbers of nodes in the recursion tree . What is the Big- for execution time? Determine a formula that expresses the height of the tree. What is the Big-? for memory? Write an iterative solution for this same problem and compare its efficiency with this . recursive solution