链接：http://poj.org/problem?id=2080
注意：上传java代码时，去掉包名，类名改为Main，这是我提交时的规范。
package demo_01_07;
import java.text.ParseException;
import java.util.Calendar;
import java.util.Scanner;
public class POJ_2080 {
public static void main(String[] args) throws ParseException {
Scanner sc = new Scanner(System.in);
Calendar cal = Calendar.getInstance();
String str_week[] = {"","Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
cal.set(Calendar.YEAR, 2000);
cal.set(Calendar.MONTH, 0);
cal.set(Calendar.DAY_OF_MONTH, 1);
int day = 0;
while( true )
{
Calendar cal2 = (Calendar) cal.clone();
int a;
day=Integer.parseInt(sc.next());
if(day == -1)break;
cal2.add(Calendar.DAY_OF_YEAR, day);
String t = "";
t += cal2.get(Calendar.YEAR) + "-";
a = (cal2.get(Calendar.MONTH)+1);
if(a < 10) t += "0" + a + "-";
else t += a + "-";
a = cal2.get(Calendar.DAY_OF_MONTH);
if(a < 10) t += "0" + a;
else t += a;
t += " " + str_week[ cal2.get(Calendar.DAY_OF_WEEK) ];
System.out.println(t);
}
}
}