2. [Recurrences, 20 points] For each of the following functions, provide A recurrence, or other expression, T(n) that describes the worst-case runtime of the function in terms of n as provided (i.e. without any optimizations) - The tightest asymptotic upper and lower bounds you can find for T(n) a. int A(int n) 1 int sum-0 for (i-0, i<>