3. Consider the following algorithm Algorithm XYZ(r, q,n) r, q, n are positive integers 1, if n = 1 then return r 2. else 3. if n is odd then return XYZ(r.q,n(-1)q 4. else return XYZ(r,q,n 1)-(n 1)q a. b. c. What does the algorithm compute? What is the recurrence relation for the algorithm? What is the time complexity of the algorithm (solve the recurrence in part b)