递归求最值

public class RecSort {
    public static void main(String[] args) {
        int[] arr={3,1,5,2,4,-1};
        int rec = rec(arr, 0, arr.length - 1);
        System.out.println(rec);

    }
    public  static int   rec(int[] arr,int l,int r){
        if(l==r)return arr[l];
        int mid=l+((r-l)>>1);
        int a=rec(arr,l,mid);
        int b=rec(arr,mid+1,r);
        return Math.max(a,b);
    }
}