星星之火
摘要:interlinkage: https://www.luogu.org/problemnew/show/P5349 description: solution: 设$g(x)=\sum_{n=0}^{∞}n^xr^n$ $rg(x)=\sum_{n=0}^{∞}n^xr^{n+1}=\sum_{n= 阅读全文
posted @ 2019-05-06 22:31 星星之火OIer 阅读(125) 评论(0) 推荐(0) 编辑