java - 如何编写没有 for 和 if 语句的代码

Question

我正在尝试在没有条件语句和循环的情况下重写我的代码。 我的代码是根据这样的指令编写的，但另外没有循环和条件语句

将输入作为开始月份和日期到结束月份和日期的程序

计算总价。

假定的输入始终正确。

输入范围为同年1月1日至12月31日

1 月 1 日是星期一。

输入开始日期始终为星期一

偶数月有 31 天，奇数月有 30 天

平日价格 -> 2 美元

周六 -> $3

周日 -> $5

如果客户预订超过 50 天，价格将持平至 1 美元

 public class test {
    int startMonth;
    int startDay;
    int endMonth;
    int endDay;
    int totalDate;

    public test (int startMonth, int startDay, int endMonth, int endDay) {
        this.endMonth = endMonth;
        this.endDay = endDay;
        this.startMonth = startMonth;
        this.startDay = startDay;
    }
    public int getPrice() {
        getTotalDate();
        int price = 0;
        int discount = totalDate > 50 ? totalDate - 50 : 0;
        System.out.println("discount " + discount);
        totalDate = totalDate > 50 ? 50 : totalDate % 50;
        System.out.println("totalData : " + totalDate);
        int sunDay = totalDate/7;
        int satDay = totalDate/7 + (totalDate%7)/6;
        int weekDay = totalDate - sunDay - satDay;
        price+= sunDay*5 + satDay*3 + weekDay*2;
        return price + discount;

    }
    public int getTotalDate() {
        int gapOfMonth = endMonth - startMonth;
        totalDate = gapOfMonth*30 + (gapOfMonth +1)/2 + (endDay - startDay);
        return totalDate;
    }

    public static void main (String[] args) {
        test t = new test(1,1,2,30);
        System.out.println("test");
        System.out.println(t.getPrice());
    }
}

Answer 1

设法在没有三元的情况下完成它

public int getPrice(int totalDay) {
    int totalPrice = 0;
    int difference = totalDay-50;
    //from https://stackoverflow.com/a/2707438/529282
    int absDifference = difference*(1-2*((3*difference)/(3*difference+1)));

    //this essentially gives the minimum value between totalDay and 50
    int before50 = (totalDay+50-absDifference)/2;

    int after50 = totalDay-before50;

    totalPrice += after50;

    //the before 50 is where the complex calculation is needed
    int before50 = totalDay - after50;

    //first, the base price for weekday
    totalPrice += before50 * 2;

    //then we add the whole week difference (sat+sun price - weekday price)
    totalPrice += (before50 / 7) * 4;

    //the we add the stray saturday if any
    totalPrice += (before50 % 7) / 6;

    return totalPrice;
}

public int getTotalDate() {
    int totalDate = 0;
    //add month difference
    totalDate += 30 * (endMonth - startMonth);

    //add day difference
    totalDate += (endDay - startDay);

    //add the extra from having 31 days every two months
    totalDate += (endMonth - startMonth) / 2;

    //if the month start from even months and the end month is different, 
    //add another day since it ends with 31
    //the trick here, if startMonth == endMonth, startMonth/endMonth = 1,
    //so 1-1 is 0, nothing get added
    //while if startMonth<endMonth, startMonth/endMont = 0, so 1-0 is 1
    totalDate += ((startMonth + 1) % 2) * (1 - startMonth / endMonth);

    return totalDate;

}