力扣704. 二分查找

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int left = 0, right = nums.size();
        int middle;
        while(left < right) {
            middle = left + (right - left) / 2;
            if(nums[middle] > target) {
                right = middle;
            } else if (nums[middle] < target) {
                left = middle + 1;
            } else {
                return middle;
            }
        }
        return -1;
    }
};