题解 | #求1+2+3+...+n#

class sum{
public:
    sum()
    {
        cnt+=i;
        i++;
    }
    static int Getret()
    {
        return cnt;
    }

private:
static int cnt;
static int i;


};

int sum::cnt =0;
int sum::i =1;


class Solution {


public:
    int Sum_Solution(int n) {
        sum a[n];
        return sum::Getret();
    }
};