import java.util.*;public class daily { public static void main(String[]args){ Scanner in=new Scanner(System.in); System.out.println("请输入年份"); int year=in.nextInt(); System.out.println("请输入月份"); int month=in.nextInt(); int sum=0; for(int i=1900;i<=year-1;i++){if(i%4==0&&i%100!=0||i%400==0) {sum+=366;}else{sum+=365;}} for(int i=1;i<=month-1;i++){if(month==2){if(year%4==0&&year%100!=0||year%400==0){sum+=29;}else{sum+=28;}} if(month==1||month==3||month==5||month==7||month==8||month==10||month==12){sum+=31;}else{sum+=30;} } int lastday=(sum+1)%7; System.out.print(lastday);}}为什么输入的星期几都是错的?请高手赐教