【20171002】Java每日一练

【插播】已知年月日求星期（1900年之后）

代码实现1：

package c2;

import java.util.Scanner;

public class C2_03 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        int month;
        int mmonth;
        int year;
        int date;
        int day;
        long total = 0;

        System.out.println("请输入年份：");
        Scanner sc3 = new Scanner(System.in);
        year = sc3.nextInt();

        System.out.println("请输入月份：");
        Scanner sc = new Scanner(System.in);
        month = sc.nextInt();

        System.out.println("请输入日期：");
        Scanner sc2 = new Scanner(System.in);
        date = sc2.nextInt();




        for(int j = 1900; j <= year ; j++)
        {
            if(((j % 100 != 0) && (j % 4 == 0)) || (j % 400) == 0){
                total+=1;
            }

        }
        total = total +(year - 1900) * 365 + date;


        for(mmonth = month -1;mmonth >=1;mmonth --){

                if(mmonth == 1)
                {
                     total += 31;continue;
                }    
                if(mmonth <= 2){
                    if(((year % 100 != 0) && (year % 4 == 0)) || (year % 400) == 0){

                            total +=29;continue;
                        }
                    else{
                            total += 28;continue;
                        }

                        }

                if(mmonth <= 3)
                {
                    total += 31;continue;
                }

                if(mmonth <= 4)
                {
                    total += 30;continue;
                }

                if(mmonth <= 5)
                {
                    total += 31;continue;
                }
                if(mmonth <= 6)
                {
                    total += 30;continue;
                }
                if(mmonth <= 7)
                {
                    total += 31;continue;
                }
                if(mmonth <= 8)
                {
                    total += 31;continue;
                }
                if(mmonth <= 9)
                {
                    total += 30;continue; 
                }
                if(mmonth <= 10)
                {
                    total += 31;continue;
                }
                if(mmonth <= 11 )
                {
                    total += 30;continue;
                }



        }



        System.out.println("这一天是第" + total + "天");

        day = (int)(total % 7);
        //System.out.println("今天是星期" + day);

        switch(day)
        {
        case 1:
            System.out.println("这一天是星期1。");
            break;
        case 2:
            System.out.println("这一天是星期2。");
            break;
        case 3:
            System.out.println("这一天是星期3。");
            break;
        case 4:
            System.out.println("这一天是星期4。");
            break;
        case 5:
            System.out.println("这一天是星期5。");
            break;
        case 6:
            System.out.println("这一天是星期6。");
            break;
        default:
            System.out.println("这一天是星期7。");

        }



    }

}

代码实现2：蔡勒公式