力扣-704题 二分查找（C++）- 数组二分法

题目链接：https://leetcode-cn.com/problems/binary-search/
题目如下：

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int low=0,high=nums.size()-1,mid;
		
		//时间复杂度为O(logn)
        while(low<=high){
            mid=(low+high)/2;
            if(nums[mid]>target) high=mid-1;
            else if(nums[mid]<target) low=mid+1;
            else if(nums[mid]==target) return mid; 
        }

        return -1;
    }
};

注：