二分查找的递归和非递归实现

最近在复习基础知识，下面是二分查找算法的递归和非递归实现：

package sortandsearch;

/**
 *@Description:<p>二分查找的递归和非递归算法</p>
 *@author 王旭
 *@time 2016-3-3 上午10:36:29
 */
public class BinarySearch {
    
    
    //非递归
    public static int binSearch1(int[] arr, int target) {
        if(arr == null || arr.length == 0)
            return -1;
        int left = 0, right = arr.length - 1;
        while(left <= right) {
            int mid = (left + right) / 2;
            if(arr[mid] == target) {
                return mid;
            }
            if(arr[mid] < target) {
                left = mid + 1;
            }
            if(arr[mid] > target) {
                right = mid - 1;
            }
        }
        return -1;
    }
    
    //递归
    public static int binSearch2(int[] arr, int target, int left, int right) {
        if(arr == null || arr.length == 0)
            return -1;
        if(left > right) {
            return -1;
        }
        int mid = (left + right) / 2;
        if(arr[mid] == target) {
            return mid;
        }
        if(arr[mid] > target) {
            return binSearch2(arr, target, left, right - 1);
        }
        if(arr[mid] < target) {
            return binSearch2(arr, target, left + 1, right);
        }
        return -1;
    }
    
    

    public static void main(String[] args) {
        int[] testArr = new int[]{1,2,3,5,8,9,12,13,15,19,20,30,50,89,101};
        System.out.println(binSearch1(testArr, 13));
        System.out.println(binSearch2(testArr, 101, 0, 14));
    }
}