万年历

/**
 * @author jliu.l
 * @2020年7月7日
 * 
 */
public class Calendar {

    public static void main(String[] args) {
        System.out.println("================万年历===============");
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入年份：");
        int year = sc.nextInt();
        System.out.print("请输入月份：");
        int month = sc.nextInt();
        int countyear = 0;//1900到此年份的天数
        
        for(int i=1900;i<year;i++) {
            //闰年：能被4整除，但是不能被100整除，或者能被400整除的数
            if((year%4==0 && year%100!=0) || (year%400==0)) {
                countyear += 366;
            }else {
                countyear += 365;
            }
        }
        //输入的月的前面的月的天数
        for(int i=1;i<month;i++) {
            switch (i) {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12: 
                countyear += 31;
                break;
            case 2:
                if((year%4==0 && year%100!=0) || (year%400==0)) {
                    countyear += 29;
                }else {
                    countyear +=28;
                }
                break;
            case 4:
            case 6:
            case 9:
            case 11:
                countyear +=30;
                break;
            default :
                break;
            }
        }
        
        int nowday = 0;
        if(month == 2) {
            if((year%4==0 && year%100!=0) || (year%400==0)) {
                nowday = 29;
            }else {
                nowday = 28;
            }
        }else if (month == 4 || month == 6 ||month == 9 ||month == 11) {
            nowday = 30;
        }else {
            nowday = 31;
        }
        System.out.println(countyear);
        System.out.println(nowday);
        System.out.println("日	一	二	三	四	五	六");
        int mday = countyear%7+1;
        
        for(int i =1; i<=mday; i++) {
            System.out.print("	");
        }
        
        for (int i = 1; i <= nowday; i++) {
            System.out.print(i+"	");
            if((mday + i) % 7 == 0){
                System.out.println();
            }
        }
    }

}