摘要：C Linear Approximation 找出$A_i i$的中位数作为$b$即可 题解 cpp include include include include include // define ivorysi define fi first define se second define M 阅读全文

摘要：题解 听说这是一道论文题orz $\sum_{k = 1}^{\infty} k(p^{k} p^{k 1})$ 答案是这个多项式的第$2^N 1$项的系数 我们反演一下，卷积变点积 $\hat{f_{S}} = \sum_{k = 1}^{\infty} k(\hat{p_{S}}^{k} \ha 阅读全文