(应用直接存取类线性表4.1.1)POJ 2080 Calendar(日期计算)

/*
 * POJ_2080.cpp
 *
 *  Created on: 2013年10月25日
 *      Author: Administrator
 */
#include <iostream>
#include <cstdio>

using namespace std;

//将起始时间的星期数作为数组的第一个元素
const char wstr[][20]={
		"Saturday",
		"Sunday",
		"Monday",
		"Tuesday",
		"Wednesday",
		"Thursday",
		"Friday"
};

//计算year有多少天
int days_of_year(int year){
	if(year % 100 == 0){
		return (year % 400 == 0) ? 366 : 365;
	}

	return (year % 4 == 0) ? 366 : 365;
}

//计算year的month月有多少天
int days_of_month(int month,int year){
	if(month == 2){
		return days_of_year(year) == 366 ? 29 : 28;
	}

	int d;
	switch(month){
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:
		d = 31;
	break;
	default:
		d = 30;
	}

	return d;
}


int main(){
	int n;
	while(scanf("%d",&n)!=EOF,n!=-1){
		int year = 2000;
		int month = 1;
		int day = 1;
		int weak = n % 7;

		while(n){
			if(n >= days_of_year(year)){
				n -= days_of_year(year);
				++year;
			}else if(n >= days_of_month(month,year)){
				n -= days_of_month(month,year);
				++month;
			}else{
				day += n;
				n = 0;
			}
		}

		cout<<year<<"-"<<(month < 10 ? "0":"")<<month<<"-"<<(day < 10 ?"0":"")<<day<<" "<<wstr[weak]<<endl;
	}

	return 0;
}