七月 27, 2021
2021牛客暑期多校训练营4 B
A Course生成函数来计数不同课的选择方案 \sum_{i=0}^n x^i = \frac{1}{1-x^n}\\ f_i(x) =\prod_{...
八月 03, 2021
Codeforces Round 736 (Div. 2) E - The Three Little Pigs
题目概述对于一个$n$,给定$q$次询问,回答 \sum_{i=1}^{n}C_{3i}^{x}数据范围 1...