找错误
当输入数字不会出现错误,但是输入=就会死循环,大家看看
int menu_select()
{

int c;

cout < < "press any key enter menu......\n ";/*提示压任意键继续*/
system( "cls ");
cout < < "********************MENU*********************\n\n ";
cout < < " 0. 查找当日是该年的第几天\n ";
cout < < " 1. 查找某年n天的日期\n ";
cout < < " 2. 查找某年的生肖年\n ";
cout < < " 3. 输入两个日期,查找日期间的差\n ";
cout < < " 4. 输入日期查询日历 \n ";
cout < < " 5. 输入日期查找是星期\n ";
cout < < " 6. 退出程序\n ";
cout < < "***********************************************\n ";
do{
cout < < "\n Enter you choice(0~6): "; /*提示输入选项*/
cin> > c; /*输入选择项*/
if(c <0||c> 6)
cout < < " It is error number ,Please enter you choice again~ ";

}while(c <0||c> 6); /*选择项不在0~11之间重输*/


return c; /*返回选择项，主程序根据该数调用相应的函数*/
}
int main()
{
for(;;)/*无限循环*/
{

switch(menu_select()) /*调用主菜单函数，返回值整数作开关语句的条件*/
{
case 0:day_total();break;
case 1:days_data();break;
case 2:cout < < "ok ";
case 3:cout < < "ok ";
case 4:cout < < "ok ";
case 5:cout < < "ok ";
case 6:cout < < " **谢谢使用!再见!** " < <endl;system( "pause ");exit(0);

}

}
system( "pause ");
return 0;
}


[解决办法]
c的类型改为char吧，后面的作相应的修改