题解 | #二分查找-I#

二分查找，本质上就是对半拆分集合，比较中间值

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) {
        // write code here
        if (nums == null || nums.length == 0) {
            return -1;
        }
        int left = 0, right = nums.length - 1, middle = left + (right - left) / 2, res = -1;
        while (left <= right) { 
            middle = left + (right - left) / 2;
            if (nums[middle] == target) {
                res = middle;
                break;
            } else if (nums[middle] > target) {
                right = middle - 1;
            } else {
                left = middle + 1;
            }
        }
        return res;
    }
}