k1+k2+k3+...+kn
by 2788151462zcz @ 2018-05-11 23:07:01
@[2788151462zcz](/space/show?uid=89562) 即$\sum_{i=1}^{n}ki$。
by Drinkkk @ 2018-05-12 07:28:03
$\color{blue}{\text{就是}\Sigma^{n}_{i=1}ki}$
by M_sea @ 2018-05-12 09:03:19
@[chen_zhe](/space/show?uid=8457) 楼上禁言了解一下
by 长河落日 @ 2018-05-12 09:55:35
```
for(int i=1;i<=n;i++)
k+=k[i];```
by VPYEKINDAR @ 2018-07-17 15:04:45
就是求和公式
by 虞战 @ 2018-07-26 17:00:24