ZOJ 2420 Calendar

 这种处理日期的方法很值得学习！很巧妙！

#include <stdio.h>
int year[2] = {365, 366};    //0 非润年
int month[2][12] = 
{
{31,28,31,30,31,30,31,31,30,31,30,31},
{31,29,31,30,31,30,31,31,30,31,30,31}
};                    //0 非润年的月份
//2000年1月1日 Saturday 
char week[7][10]={"Saturday","Sunday","Monday","Tuesday","Wednesday","Thursday","Friday"};
int isRun(int y){
    if((y % 400 == 0) || (y % 4 == 0 && y % 100 != 0) )
        return 1;    //返回1 润年
    return 0;
}
int main(){
    int day, dayOfweek;
    while( scanf("%d",&day) == 1 && day != -1 ){
        dayOfweek = day % 7;        //day 对7 取模可以知道是周几 得先知道2000年1月1日 是周几
        int i, j;
        for(i = 2000; day >= year[isRun(i)]; ++i){
            day -= year[isRun(i)];
        }
        for(j = 0; day >= month[isRun(i)][j]; ++j){    //i， j， k这些 别搞错     
            day -= month[isRun(i)][j];
        }
        printf("%d-%02d-%02d %s\n",i, j + 1, day + 1, week[dayOfweek]);
    }
    return 0;
}
/*
2004-09-26 Sunday
2004-10-06 Wednesday
2004-10-16 Saturday
2004-10-17 Sunday
*/