啊哈哈哈，挺简单的

class Solution {
public:
vectora;
void Insert(int num)
{
a.insert(a.begin(),num);
}

double GetMedian()
{ 
sort (a.begin(),a.end());
    if(a.size()%2==1)
        return (double)*(a.begin()+(a.size()-1)/2);
     else if(a.size()%2==0)
        return (double)(*(a.begin()+a.size()/2)+*(a.begin()+a.size()/2-1))/2;
}

};