Consider the following algorithm. ALGORITHM Mystery (n) //Input: A nonnegative integer n S 0 for i 1 to n do S + S + i*i return S a. What does this algorithm compute? b. What is its basic operation? c. How many times is the basic operation executed? d. What is the efficiency class of this algorithm? e. Suggest an improvement or a better algorithm altogether and indicate its efficiency class. If you cannot do it, try to prove that in fact it cannot be done.