题解 | 二分查找-I

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型一维数组 
     * @param target int整型 
     * @return int整型
     */
    public int search (int[] nums, int target) {
       if (nums == null || nums.length == 0) {
            return -1;
        }
        return search(nums, target, 0, nums.length - 1);
    }

    public static int search(int[] nums, int target, int start, int end) {
        if (start > end) {
            return -1;
        }
        int mid = start + (end - start) / 2;
        if (nums[mid] == target) {
            return mid;
        } else if (nums[mid] < target) {
            return search(nums, target, mid + 1, end);
        } else {
            return search(nums, target, start, mid - 1);
        }
    }
}