摘要: 题面 题解 设 \(\mathbf f' = \mathbf f * \mu\),\(G_{\mathbf f} (n) = \sum_{n | d} \mathbf f(d)\),记 \((i, j) = \gcd(i, j)\),\([i, j] = \operatorname{lcm}(i, 阅读全文
posted @ 2020-08-17 19:56 xgzc 阅读(296) 评论(0) 推荐(2) 编辑