编辑代码

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