Consider the following algorithm

Algorithm XYZ(r,q,n) \ ,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)+(n-1)q 4. else return XYZ(r,q,n-1)-(n-1)q

a) What does the algorithm compute?

b) What is the recurrence relation for the algorithm?

c) What is the time complexity of the algorithm (solve the recurrence in part b).