大家看看小弟我写的这段代码算法上的有关问题，验证和实际不符

//这个测试类是得到某年某月一号星期几，从1990年一月一号开始算起的（1990年一月一号星期一）import java.util.GregorianCalendar;public class TestgetFirstDayOfMonth{    public static void main(String[] args)    {        int m=getFirstDay(2012,2);  //这个是测试        System.out.println("m="+m);    }    public static  int getFirstDay(int year,int month)    {        int totalDay=0,totalYearDay=0,totalMonthDay=0,yearDay=0,monthDay=0;            if(year<1900)        {            return(-1);                    }        if((month<1)||(month>12))        {            return(-1);        }                   if (year % 4 == 0 && !(year % 100 == 0) || year % 400 == 0)   //判断是不是闰年，闰年加366，平年加365            {                yearDay=366;            }            else            {                yearDay=365;            }            for(int i=1900;i<year;i++)                            {                totalYearDay = totalYearDay + yearDay;            }                for (int i = 1; i <= month; i++) {            switch (i) {              case 1:              case 3:              case 5:              case 7:              case 8:              case 10:              case 12:                monthDay = 31;                break;              case 2:                if (year % 4 == 0 && !(year % 100 == 0) || year % 400 == 0) {                    monthDay = 29;                } else {                    monthDay = 28;                }                break;              default:                monthDay = 30;                break;            }                        if (i < month) {                totalMonthDay = totalMonthDay + monthDay;            }                    }        for(int i=1;i<month;i++)                            {                totalMonthDay = totalMonthDay + monthDay;            }                totalDay=totalYearDay+totalMonthDay;        return((totalDay+1)%7);    }}        

import java.util.GregorianCalendar;public class TestgetFirstDayOfMonth{    public static void main(String[] args)    {        int m=getFirstDay(2012,2);  //这个是测试        System.out.println("m="+m);    }    public static  int getFirstDay(int year,int month)    {        int totalDay=0,totalYearDay=0,totalMonthDay=0,yearDay=0,monthDay=0;            if(year<1900)        {            return(-1);                    }        if((month<1)||(month>12))        {            return(-1);        }               for(int i=1900;i<year;i++)                    {            //判断闰年的代码应该放在这儿，而且应该是用i来判断的            if (i % 4 == 0 && !(i % 100 == 0) || i % 400 == 0)   //判断是不是闰年，闰年加366，平年加365            {                yearDay=366;            }            else            {                yearDay=365;            }            totalYearDay = totalYearDay + yearDay;        }                for (int i = 1; i < month; i++) {    //我把这里的等号去掉了            switch (i) {              case 1:              case 3:              case 5:              case 7:              case 8:              case 10:              case 12:                monthDay = 31;                break;              case 2:                if (year % 4 == 0 && !(year % 100 == 0) || year % 400 == 0) {                    monthDay = 29;                } else {                    monthDay = 28;                }                break;              default:                monthDay = 30;                break;            }                        //if (i < month) {        //这个判断多此一举            totalMonthDay = totalMonthDay + monthDay;            //}                }       /* for(int i=1;i<month;i++)    //这些都不需要了                            {                totalMonthDay = totalMonthDay + monthDay;            }*/                totalDay=totalYearDay+totalMonthDay;        return((totalDay+1)%7);    }}