Jobdu-1096-日期差值

Question

• 题目描述：

  有两个日期，求两个日期之间的天数，如果两个日期是连续的我们规定他们之间的天数为两天

• 输入：

  有多组数据，每组数据有两行，分别表示两个日期，形式为YYYYMMDD

• 输出：

  每组数据输出一行，即日期差值

• 样例输入：

  2011041220110422

• 样例输出：

  11

Answer

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int date1 = sc.nextInt();
        int date2 = sc.nextInt();
        // exchange, s.t. date1 < date2
        int temp;
        if(date1 < date2){
            temp = date1;
            date1 = date2;
            date2 = temp;
        }
        int year1, month1, day1, year2, month2, day2;
        year1 = date1 / 10000;
        month1 = (date1 / 100) % 100;
        day1 = date1 % 100;
        year2 = date2 / 10000;
        month2 = (date2 / 100) % 100;
        day2 = date2 % 100;
        System.out.println(diffBetweenDates(year1, month1, day1, year2, month2, day2));
    }

    public static int diffBetweenDates(int year1, int month1, int day1, int year2, int month2, int day2){
        int count = 0;
        if(year1 == year2){
            return Math.abs(countDaySinceNewYear(year1, month1, day1)-countDaySinceNewYear(year2, month2, day2));
        }else{
            for(int i=year1+1;i<year2;i++){
                if(isLeap(i))
                    count += 366;
                else
                    count += 365;
            }
            if(isLeap(year1))
                return 367 - countDaySinceNewYear(year1, month1, day1) + count + countDaySinceNewYear(year2, month2, day2) + 1;//要求相邻两天相差2天
            else
                return 366 - countDaySinceNewYear(year1, month1, day1) + count + countDaySinceNewYear(year2, month2, day2) + 1;
        }
    }
    public static boolean isLeap(int year){
        //四年一闰 百年不闰 四百年再闰
        if(year%4==0&&year%100!=0 || year%400==0)
            return true;
        else
            return  false;
    }
    public static int countDaySinceNewYear(int year, int month, int day){
        int[] LeapMonth = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        int[] CommonMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        int farAwayFromNewYear = 0;
        if(isLeap(year)){
            for(int i=0;i<month;i++){
                farAwayFromNewYear += LeapMonth[i];
            }
            farAwayFromNewYear += day;
        }else{
            for(int i=0;i<month;i++){
                farAwayFromNewYear += CommonMonth[i];
            }
            farAwayFromNewYear += day;
        }
        return farAwayFromNewYear;
    }
}