172. 배열을 반으로 나누는 재귀 합계

1public class Main {
2    static int calls = 0;
3 
4    static int sum(int[] a, int lo, int hi) {
5        calls++;
6        if (lo == hi) {
7            return a[lo];
8        }
9        int mid = (lo + hi) / 2;
10        return sum(a, lo, mid) + sum(a, mid + 1, hi);
11    }
12 
13    public static void main(String[] args) {
14        int[] a = {2, 5, 1, 4, 3};
15        int total = sum(a, 0, 4);
16        System.out.println(total + " " + calls);
17    }
18}