题解 | #求1+2+3+...+n#

class Solution {
public:
    Solution()
    {
        count++;
        sum += count;
    }
    int Sum_Solution(int n) {
        Solution arr[n];
        return sum;
    }
    static int count;
    static int sum;
};
int Solution::count = -1;
int Solution::sum = 0;