Given an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. If target exists, then return its index. Otherwise, return -1.

You must write an algorithm with O(log n) runtime complexity.

Example 1:

Input: nums = [-1,0,3,5,9,12], target = 9
Output: 4
Explanation: 9 exists in nums and its index is 4
Example 2:

Input: nums = [-1,0,3,5,9,12], target = 2
Output: -1
Explanation: 2 does not exist in nums so return -1

Constraints:

1 <= nums.length <= 104
-104 < nums[i], target < 104
All the integers in nums are unique.
nums is sorted in ascending order.

solution:

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