题解 | #二分查找-I#

注意边界！！！

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) {
        int numsLength = nums.length;

        int left = 0;
        int right = 0;
        int middle = 0;

        if (numsLength != 0) {
            right = numsLength - 1;
            if (nums[left] == target)
                return left;

            if (nums[right] == target)
                return right;
        }

        if (numsLength == 0 || nums == null)
            return -1;

        while (left < right) {
            middle = (right + left) / 2;
            if (nums[middle] == target) {
                return middle;
            } else if (nums[middle] > target) {
                right--;
            } else if (nums[middle] < target) {
                left++;
            }
        }
        return nums[middle] == target ? middle : -1;
    }
}