题解 | #求1+2+3+...+n#
求1+2+3+...+n
https://www.nowcoder.com/practice/7a0da8fc483247ff8800059e12d7caf1
class A { public: A() { _sum+=_i; _i++; } static int GetSum() { return _sum; } private: static int _i; static int _sum; }; int A::_i=1; int A::_sum=0; class Solution { public: int Sum_Solution(int n) { A a[n]; return A::GetSum(); } };