两位数加法测试

package com;

import java.text.DecimalFormat;
import java.util.Random;
import java.util.Scanner;

public class math {
    public static void main(String[] args) {

        Random random = new Random();    //实例化Random
        double a = random.nextDouble(90)+10, b = random.nextDouble(90)+10;      //初始化a、b两个数
        Scanner sc = new Scanner(System.in);    //实例化Scanner
        int ATK = 0;    //用户能力值
        int i = 1;     //循环变量i

        //菜单
        System.out.println("----------------------------");
        System.out.println("**\t\t 数学加法运算\t\t  **");
        System.out.println("**\t\t(1) 简单模式 \t\t  **");
        System.out.println("**\t\t(2) 进阶模式 \t\t  **");
        System.out.println("**\t\t(3) 游戏规则 \t\t  **");
        System.out.println("**\t\t(4) 退出游戏 \t\t  **");
        System.out.println("----------------------------");
        System.out.print("**\t请选择: > ");

        int choice = sc.nextInt();
        switch(choice){
            case 1:
                while(i<=10) {
                    DecimalFormat de = new DecimalFormat("0.00");   //限制数字格式
                    String  a1 = de.format(a);
                    String  b1 = de.format(b);
                    String  res1 = de.format(a+b);
                    double res = Double.parseDouble(res1);  //将String转换成double类型
                    System.out.print("("+i+") "+a1+ "+" + b1 + "="+res1);
                    if (res == sc.nextDouble()) {
                        ATK += 2;
                        System.out.println("ATK+2,当前ATK:"+ATK);
                    } else {
                        System.out.print("答案错误，您还有一次作答机会。。。\n"+"("+i+") "+a1+ "+" + b1 + "=");
                        if (res == sc.nextDouble()) {
                            ATK++;
                            System.out.println("ATK+1,当前ATK:"+ATK);
                        } else {
                            ATK-=2;
                            System.out.println("ATK-2,当前ATK:"+ATK);
                        }
                    }
                    i++;

                }
                System.out.println("当前ATK:"+ATK);
                System.out.println("---------------------------");
                System.out.print("\t恭喜你!达成段位:");
                switch (ATK/2){
                    case 0: System.out.println("倔强青铜");break;
                    case 1: System.out.println("秩序白银");break;
                    case 2: System.out.println("荣耀黄金");break;
                    case 3:
                    case 4: System.out.println("尊贵铂金");break;
                    case 5:
                    case 6: System.out.println("永恒钻石");break;
                    case 7:
                    case 8:System.out.println("最强王者");break;
                    case 9:
                    case 10: System.out.println("荣耀王者");break;
                    default:System.out.println("快乐黑铁");break;
                }
                System.out.println("---------------------------");


                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                System.out.println("游戏退出");
                break;

        }



    }
}