import java.util.Scanner;

public class Shop {
	public static void main(String[] args) {
		System.out.println("MyShopping管理系统>购物结算");
		System.out.println("********************************");
		System.out.println("请选择购买的商品编号：");
		System.out.println("1.T恤               2.网球鞋             3.网球拍");
		System.out.println("********************************");
		String j = "y";
		double price1 = 245;// 商品单价
		double price2 = 570;
		double price3 = 770;
		int n1 = 0, n2 = 0, n3 = 0;// 各个商品数量
		do {
			Scanner input = new Scanner(System.in);
			System.out.print("请输入商品编号：");
			int i = input.nextInt();
			System.out.print("请输入购买数量：");
			int n = input.nextInt();
			switch (i) {
			case 1:
				n1 = n1 + n;
				double p1 = n * price1;// 此项金额
				System.out.println("T 恤  ￥245.0\t数量 " + n + "\t合计 ￥" + p1);
				break;
			case 2:
				double p2 = n * price2;
				n2 = n2 + n;
				System.out.println("网球鞋 ￥570.0\t数量 " + n + "\t合计 ￥" + p2);
				break;
			case 3:
				double p3 = n * price3;
				n3 = n3 + n;
				System.out.println("网球拍  ￥770.0\t数量 " + n + "\t合计 ￥" + p3);
				break;
			default:
				System.out.println("输入错误");
			}
			System.out.print("\n是否继续（y/n）:");
			Scanner input2 = new Scanner(System.in);
			j = input2.next();
		} while ("y".equals(j));

		System.out.println("折扣：0.8");
		double p = 0.8 * (n1 * price1 + n2 * price2 + n3 * price3);// 计算总金额
		System.out.println("应付金额：" + p);
		System.out.print("实付金额：");
		Scanner input3 = new Scanner(System.in);
		double q = input3.nextDouble();
		double m = q - p;
		System.out.println("找钱：" + m);
	}
}