求助，请高手帮下忙，多谢！
求助
编写一个函数，以一个日期某年某月某日为参数，返回该日期是星期几（已知公元一年一月一日是星期一），在MAIN（）函数输入日期输出星期几。（提示：计算公无一年一月一日到该日期的天数，该天除以七的佘数是零是星期天，佘数为一是生期一，如此类推）
THANK YOU！
#include "iostream.h"
#include "stdlib.h"
int day(int year,int month,int date);
void main()
{
int year,month,date;
cout <<"请输入日期（yyyy mm dd）：";
cin >>year>>month>>date;
cout <<"这天是星期"<<day(year,month,date)<<endl;
}
int day(int year,int month,int date)
{
long number=0;
if (month<0 || month>12 || date<0 || date>31)
{
cout <<"输入的日期有误"<<endl;
exit(1);
}
number=year/400*(400*365+(4*24+1))+year%400/100*(365*100+24)+year%100/4*(4*365+1)+year%100%4*365;
switch (month)
{
case 12:
cout <<number <<endl;
number=number+30;
case 11:
cout <<number <<endl;
number=number+31;
case 10:
cout <<number <<endl;
number=number+30;
case 9:
cout <<number <<endl;
number=number+31;
case 8:
cout <<number <<endl;
number=number+31;
case 7:
cout <<number <<endl;
number=number+30;
case 6:
cout <<number <<endl;
number=number+31;
case 5:
cout <<number <<endl;
number=number+30;
case 4:
cout <<number <<endl;
number=number+31;
case 3:
cout <<number <<endl;
number=number+(((year%4==0 && year%100!=0)||year%400==0)?29:28);
case 2:
cout <<number <<endl;
number=number+31;
default:
;
}
cout <<number <<endl;
number=number+date-1;
return number%7;
}
好像还是有地方错了。我对过日子不怎么敏感的，哈哈。再请高手看看吧……
