摘要：
一道纯粹的容斥原理题！！不过有一个trick，就是会出现重复的，害我WA了几次！！代码：#include#include#include#include#include#include#include#define ll long long#define mod 55566677using namespace std;int p[52],ans;int m,n;bool visd[52],visc[52],vis[52][52];struct point{ int a,b;}q[30];void dfs(int s,int i,int f){ ans=(ans+f*p[n-s])%... 阅读全文