书的价钱

设计思路：没什么思路，知道书买多了的规律，还是很好做的。

package time1;
import java.util.InputMismatchException;
import java.util.Scanner;
public class book02 {
    public static void main(String[] args)
    {
        int bookNum = 0;
        double money = 0;
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入您要买的书的数量:");
        try{
            bookNum = sc.nextInt();
        }
        catch(InputMismatchException e)
        {
            System.out.println("你的输入有误");
        }
        if(bookNum == 3)
        {
            money = 21.6;
        }
        else if(bookNum % 5 == 3)
        {
            money = bookNum*8 - ((bookNum - 8)%5)*10 - 12.8;
        }
        else if(bookNum % 5 == 1)
        {
            money = (bookNum/5)*30 + 8;
        }
        else if(bookNum % 5 == 2)
        {
            money = (bookNum/5)*30 + 15.2;
        }
        else if(bookNum % 5 == 4)
        {
            money = (bookNum/5)*30 + 25.6;
        }
        else if(bookNum % 5 == 0)
        {
            money = (bookNum/5)*30;
        }
        System.out.println("书价最便宜是:"+money);
          }
}