ZOJ 3785What day is that day?（循环节找规律）

 

被坑死了，居然是294一个循环！！！打表吧，能发现规律的，有了规律，这题就特别简单

有一个小知识点

（a + b + c）%mod = a%mod + b%mod +c%mod;

(a * b * c)%mod = (a%mod)*(b%mod)*(c%mod);

 

#include <iostream>using namespace std;int a[300];char d[8][10] = {"Saturday","Sunday","Monday","Tuesday","Wednesday","Thursday","Friday"};void init(){int ans,sum=0;for(int i=1;i<=294;i++){ans=1;for(int j=1;j<=i;j++){ans = (ans*(i%7))%7; }sum = (sum + ans)%7;a[i] = sum % 7;}}int main(){int n;int t;cin>>t;init();while(t--){cin>>n;int m = n%294;cout<<d[a[m]]<<endl;}return 0;}