摘要: 757E. Bash Plays with Functions 题意:定义函数 \(f_0(n) = \sum_{u * v =n} [gcd(u, v) = 1]\) \(f_{r + 1}(n) = \sum_{u*v = n} \frac{f_r(u) + f_r(v)}{2}\) 给定 \( 阅读全文
posted @ 2021-11-01 23:58 Time_Limit_Exceeded 阅读(38) 评论(0) 推荐(0) 编辑