In mathematics you don't understand things, you just get used to them.

标签 combinatorics 下的文章

Link.A. 赢钱 (money)人类智慧题, 好像是写成二进制小数, 每次用 Least Significant Bit 去赌? 不是很能理解...B. 排列 (per)贡献可以分成五类: ...

Link.今天的题解写得有点水, 没什么参考价值.A. 出关 (laozi)可以写出朴素的方程式:$$ f_{i}+A_{s_i} \rightarrowtail f_{i+1} \\ f_i+...