单选题：Suppose that the devide-and-conquer strategy is used to find the

Suppose that the devide-and-conquer strategy is used to find the maximum and the minimum of $$N$$ positive numbers. At each step, the problem is divided into 2 sub-problems of size $$N/2$$. Then the time recurrences is $$T(N) = 2T(N/2)+f(N)$$, where $$f(N)$$ is ____. @[B](2)

A. $$\Omega (N)$$
B. $$O(1)$$
C. $$N/2$$
D. $$\Theta (logN)$$




A.$$\Omega (N)$$
B.$$O(1)$$
C.$$N/2$$
D.$$\Theta (logN)$$


答案：B