摘要：```cpp 【题目描述】 原题来自：USACO 2009 Feb. Silver 牡 mǔ，畜父也。牝 pìn，畜母也。 ——《说文解字》 约翰要带 N 只牛去参加集会里的展示活动，这些牛可以是牡牛，也可以是牝牛。牛们要站成一排，但是牡牛是好斗的，为了避免牡牛闹出乱子，约翰决定任意两只牡牛之间至少 阅读全文

摘要：```cpp include include include include include include include include using namespace std; const int N=100005; int n,m,p; long long A[N+5],B[N+5]; in 阅读全文

摘要：题面:https://www.luogu.org/problem/P2822 cpp 本题直接将c[i][j]%k=1的(i,j)用前缀和数组记录下来,然后求前缀和即可. 注意:ans[i][j]=ans[i 1][j]+ans[i][j 1] ans[i 1][j 1] Code: include 阅读全文