class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
     *
     * 
     * @param nums int整型vector 
     * @param target int整型 
     * @return int整型
     */
    int search(vector<int>& nums, int target) {
        // write code here
        if(nums.size()==0)return -1;
        int n = nums.size();
        int i = 0, j = n-1;
        int mid = (i+j)/2;
        for(; i <= n-1 &&j >=0; )
        {
            if(nums[mid] < target )
            {
                i++;
                mid = i;
            }
            else if(nums[mid] > target)
            {
                j--;
                mid = j;
            }
            else 
            {
                return mid;
            }
        }
        return -1;
    }
};