ZOJ 3876 May Day Holiday（找规律||打表-基姆拉尔森计算公式(求某年某月某日星期几)）
As a university advocating self-learning and work-rest balance, Marjar University has so many days of rest, including holidays and weekends. Each weekend, which consists of Saturday and Sunday, is a rest time in the Marjar University.
The May Day, also known as International Workers' Day or International Labour Day, falls on May 1st. In Marjar University, the May Day holiday is a five-day vacation from May 1st to May 5th. Due to Saturday or Sunday may be adjacent to the May Day holiday, the continuous vacation may be as long as nine days in reality. For example, the May Day in 2015 is Friday so the continuous vacation is only 5 days (May 1st to May 5th). And the May Day in 2016 is Sunday so the continuous vacation is 6 days (April 30th to May 5th). In 2017, the May Day is Monday so the vacation is 9 days (April 29th to May 7th). How excited!
Edward, the headmaster of Marjar University, is very curious how long is the continuous vacation containing May Day in different years. Can you help him?
Input
There are multiple test cases. The first line of input contains an integer T indicating the number of test cases. For each test case, there is an integery (1928 <=y <= 9999) in one line, indicating the year of Edward's query.
Output
For each case, print the number of days of the continuous vacation in that year.
Sample Input
3 2015 2016 2017
Output
5 6 9Author: ZHOU, Yuchen
Source: The 12th Zhejiang Provincial Collegiate Programming Contest
题目意思是五一节是5.1-5.5，但是如果有周六周日就连着在一起放了，问这样每年能放多少天假。
当时就调出了window下的日历看了一下规律：
今年是N年（平年），五一是周M，则N+1年时，五一是周M+1；今年是N年（闰年），五一是周M，则N+1年时，五一是周M+2
看了一下网上的代码，可以打表，方便很多，但是当时我自己就只想到了找规律这种方法。
打表：
/*
* Copyright (c) 2016, 烟台大学计算机与控制工程学院
* All rights reserved.
* 文件名称：mayday.cpp
* 作 者：单昕昕
* 完成日期：2016年4月5日
* 版 本 号：v1.0
*/
#include <iostream>
using namespace std;
int main()
{
int t,y,m=5,d=1;
cin>>t;
int a[7]= {6,9,6,5,5,5,5};//五一是周日到周六中的某天时放假的天数
while(t--)
{
cin>>y;
if(m==1||m==2)//此处表示把1，2月计算到上一年的13，14月
m+=12,y--;
int week=(d+2*m+3*(m+1)/5+y+y/4-y/100+y/400+1)%7;//基姆拉尔森计算公式(求某年某月某日星期几)
cout<<a[week]<<endl;
}
return 0;
}
找规律：
/*
* Copyright (c) 2016, 烟台大学计算机与控制工程学院
* All rights reserved.
* 文件名称：zoj.cpp
* 作 者：单昕昕
* 完成日期：2016年4月2日
* 版 本 号：v1.0
*/
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
int a[1000005];
using namespace std;
void f(int d)
{
//cout<<"*"<<d<<endl;
if(d==1)
cout<<"9"<<endl;
else if(d==2||d==7)
cout<<"6"<<endl;
else cout<<"5"<<endl;
}
int main()
{
int t,i;
scanf("%d",&t);
int y;
while(t--)
{
int d=1;
scanf("%d",&y);
if(y>=2000)//我这里以2000年为基准，这天周一
{
for(i=2001; i<=y; ++i)
{
if((i%4==0&&i%100!=0)||i%400==0)//闰年
d+=2;
else
++d;
if(d>7)
d%=7;
}
}
else
{
for(i=2000; i>y; --i)
{
if((i%4==0&&i%100!=0)||i%400==0)
d-=2;
else
--d;
if(d==0)
d=7;
if(d==-1)
d=6;
}
}
f(d);//根据周d判断五一放几天
}
return 0;
}