day14

 1     int search(vector<int>& nums, int target) {
 2         // write code here
 3         int left = 0;
 4         int right = nums.size() - 1;
 5         while (left <= right) {
 6             int middle = (left + right) / 2;
 7             if (nums[middle] > target) {
 8                 right = middle - 1;
 9             }
10             else if(nums[middle] < target){
11                 left = middle + 1;
12             }
13             else{
14                 return middle;
15             }
16         }
17         return -1;
18     }