根据输入年月计算该月份的天数

int DayOfMonth(int year, int month)
{    
switch(month)    
{    
case 1:    
case 3:    
case 5:    
case 7:    
case 8:    
case 10:   
case 12:        
return 31;    
case 4:    
case 6:    
case 9:    
case 11:        
return 30;    
case 2:        
if((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)        
{            
	return 29;        
}        
else        
{            
	return 28;        
}    
default:        
return 0;    
}
}