《哈利波特》最低折扣

import java.util.Scanner;

public class BuyBook {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入需要购买书本的数量：");
        int booknumber = sc.nextInt();
        int num=booknumber%5;//除5求余数
        double price=0;
        switch(num)
        {
        case 0://买的数量刚好为5的倍数
            price=booknumber*8*0.75;
            break;
        case 1://买的数量除5余1
            price=(booknumber-1)*8*0.75+8;
            break;
        case 2://买的数量除5余2
            price=(booknumber-2)*8*0.75+2*8*0.95;
        case 3://买的数量除5余3
            if(booknumber==3)
            {
                price=3*8*0.9;
            }
            else
            {
                price=(booknumber-8)*8*0.75+2*4*8*0.8;
            }
            break;
        case 4://买的数量除5余4
            price=(booknumber-4)*8*0.75+4*8*0.8;
            break;
        }
        System.out.println("购书的最低价格为"+price);
    }
}