###### 爆long long 了
by cloud_9 @ 2018-11-04 16:28:19
```
s[i]*f[cnt]*f[n-cnt]
```s[i]*f[cnt]*f[n-cnt]
```
by cloud_9 @ 2018-11-04 16:28:56
@[钱逸凡](/space/show?uid=28088)
by cloud_9 @ 2018-11-04 16:32:22
@[uncured](/space/show?uid=109440)
感谢dalao
~~如果考试时考虑了我就310了~~
by 钱逸凡 @ 2018-11-04 17:02:48
谢谢，很有帮助
另（和楼上一样，哈哈290）
by n0000000000o @ 2018-11-06 10:38:15