zyn_615的博客

Statement pro Solution 拆式子，发现答案为: ∑i=0n∑j=1a+id∑xjxk\sum_{i=0}^n\sum_{j=1}^{a+id}\sum_{x}^jx^ki=0∑n​j=1∑a+id​x∑j​xk 直接暴力插值即可，时间复杂度为O(Tk3)\mathcal O(Tk^3)O(Tk3) #include <bits/stdc++.h> using namespace std; const int MAXK = 2021; const unsigned int