求1+2+3+...+n

class Solution {
public:

    Solution()
        {
        ++n;
        sum+=n;
    }
    static void reset()
        {
        n=0;
        sum=0;
        
    }
    static int getSum()
        {
        return sum;
    }
    int Sum_Solution(int n) {
        reset();
        Solution *a=new Solution[n];
        delete[] a;
        a=NULL;
      return  getSum();
    }
    
private:
    static int n;
    static int sum;
};
int Solution::n=0;
int Solution::sum=0;