Binary search method

come from 704. Two points search
The framework is as follows ：

//  Version 2 
class Solution {
    
public:
    int search(vector<int>& nums, int target) {
    
        int left = 0;
        int right = nums.size(); //  Definition target In the interval between left closed and right open , namely ：[left, right)
        while (left < right) {
     //  because left == right When , stay [left, right) It's invalid space , So use  <
            int middle = left + ((right - left) >> 1);
            if (nums[middle] > target) {
    
                right = middle; // target  In the left range , stay [left, middle) in 
            } else if (nums[middle] < target) {
    
                left = middle + 1; // target  In the right range , stay [middle + 1, right) in 
            } else {
     // nums[middle] == target
                return middle; //  Target value found in array , Return the subscript directly 
            }
        }
        //  Target value not found 
        return -1;
    }
};