输入日期求星期的C程序源码

输入日期求星期的C程序源码

/**
* week.c
* version:1.0 2006-9-14
* auther:jsp
*
* W= (d+2*m+3*(m+1)/5+y+y/4-y/100+y/400) mod 7
* 在公式中d表示日期中的日数，m表示月份数，y表示年数。
* 注意：在公式中有个与其他公式不同的地方：
* 把一月和二月看成是上一年的十三月和十四月，例：如果是2004-1-10则换算成：2003-13-10来代入公式计算。
*/
#include"stdio.h"

struct data{
short year;
short month;
short day;
};

int IsLoopYear(struct data *today)
{
if((today->year % 400 == 0)||((today->year % 100 != 0) &&(today->year % 4 == 0)))
return 1;
else return 0;
}

void main()
{
struct data today,ctoday;
short week;

while(1)
{
printf("请输入今天的日期(dddd-dd-dd):");
scanf("%d-%d-%d",&today.year ,&today.month ,&today.day);
if(today.month ==2)
if (IsLoopYear(&today) == 1)
if((today.day > 29) || (today.day < 1))
{
printf("日期输入错误请重来!/n");
continue;
}

if(today.month ==2)
if (IsLoopYear(&today) == 0)
if((today.day > 28) ||(today.day < 1))
{
printf("日期输入错误请重来!/n");
continue;
}

if((today.month == 1) || (today.month == 3) ||(today.month == 5)||(today.month == 7)||(today.month == 8)||(today.month == 10)||(today.month == 12))
if((today.day > 31) ||(today.day < 1))
{
printf("日期输入错误请重来!/n");
continue;
}
if((today.month == 4) || (today.month == 6) ||(today.month == 9)||(today.month == 11))
if((today.day > 30) ||(today.day < 1))
{
printf("日期输入错误请重来!/n");
continue;
}

if((today.month >12) || (today.month < 1))
{
printf("月份输入错误请重来!/n");
continue;

}

ctoday = today;
if(today.month == 1 )
{
today.month = 13;
today.year = today.year-1;
}

if(today.month == 2 )
{
today.month = 14;
today.year = today.year-1;
}

week = (today.day + 2*today.month +3*(today.month + 1)/5+today.year +today.year /4-today.year /100+today.year /400) %7;
week ++;

switch(week)
{
case 1:
printf("%d年%d月%d日是星期一/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 2:
printf("%d年%d月%d日是星期二/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 3:
printf("%d年%d月%d日是星期三/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 4:
printf("%d年%d月%d日是星期四/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 5:
printf("%d年%d月%d日是星期五/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 6:
printf("%d年%d月%d日是星期六/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
case 7:
printf("%d年%d月%d日是星期天/n",ctoday.year ,ctoday.month ,ctoday.day );
break;
}
}
}