[面试算法题重做]求1+2+...+n

class Sum {
public:
    Sum() {num++; sum+=num;}
    static void Reset() {num = 0; sum = 0;}
    static int GetSum() {
        return sum;
    }
private:
    static int num;
    static int sum;
};

int Sum::num = 0;
int Sum::sum = 0;

int SS(int i) {
    Sum::Reset();
    Sum *p = new Sum[i];
    delete []p;
    p = NULL;

    return Sum::GetSum();
}

int addfunc(int i){
    int r = 0;
    i && (r= i + addfunc(i-1) );
    return r;
}