小学生口算题卡系统

//小学生口算题卡系统(不能为负数和小数,小小学生还不知道)
import java.util.Scanner;

public class SwitchFor {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner input = new Scanner(System.in);
		int m1 = 1234;
		int pass;
		int sum1 = 0,sum2 = 0;//总题数，对题数
		//int i;
		int x,y,i = 1;
		int z,j,choice;
		int num;
		System.out.println("<<欢迎使用天命学习软件>>");
		System.out.println("密码只能输入三次");
		while(i <= 3)
		{
		System.out.println("请输入密码:");
		pass = input.nextInt();
		
		if(pass == m1)
		{
			System.out.println("恭喜你，登陆成功");
		
		
		
		while(true)
		{
			System.out.println("1,加法运算");
			System.out.println("2,减法运算");
			System.out.println("3,乘法运算");
			System.out.println("4,除法运算");
			System.out.println("5,退出系统");
			System.out.print("请输入你的选择");
			choice = input.nextInt();
			
			switch(choice)
			{  
			case 1:
				
				System.out.print("请输入你要完成的题目数:");
				num = input.nextInt();
				for(i = 1;i <= num;i ++)
				{
					x = (int)(Math.random() * 10);
					y = (int)(Math.random() * 10);
					System.out.print(x + "+" + y + "=");
					z = input.nextInt();
					if(z == (x + y))
					{
						System.out.println("恭喜你，回答正确");
						sum2 ++;
					}
					else
					{
						System.out.println("答案错误,正确答案为:" + x + "+" + y + "=" + (x + y));
					}
					sum1 ++;
				}
				break;
			case 2:
				System.out.print("请输入你要完成的题目数:");
				num = input.nextInt();
				for(i = 1;i <= num;)
				{
					
					x = (int)(Math.random() * 10);
					y = (int)(Math.random() * 10);
					if(x > y)
					{
						System.out.print(x + "-" + y + "=");
						z = input.nextInt();
						if(z == (x - y))
						{
							System.out.println("恭喜你，回答正确");
							sum2 ++;
						}
						else
						{
							System.out.println("答案错误,正确答案为:" + x + "-" + y + "=" + (x + y));
						}
					    sum1 ++;
						i ++;
					}
				}
				break;
			case 3:
				System.out.print("请输入你要完成的题目数:");
				num = input.nextInt();
				for(i = 1;i <= num;i ++)
				{
					x = (int)(Math.random() * 10);
					y = (int)(Math.random() * 10);
					System.out.print(x + "*" + y + "=");
					z = input.nextInt();
					if(z == (x * y))
					{
						System.out.println("恭喜你，回答正确");
						sum2 ++;
					}
					else
					{
						System.out.println("答案错误,正确答案为:" + x + "*3" + y + "=" + (x + y));
					}
				   sum1 ++;
				}
				
				
				break;
			case 4:
				
				System.out.println("友情提示:只写整数部分，不用考虑四舍五入");
				System.out.print("请输入你要完成的题目数:");
				num = input.nextInt();
				for(i = 1;i <= num;)
				{
					x = (int)(Math.random() * 10);
					y = (int)(Math.random() * 10);
					if(x > y && y != 0)
					{
						System.out.print(x + "/" + y + "=");
						z = input.nextInt();
						if(z == (x / y))
						{
							System.out.println("恭喜你，回答正确");
							sum2 ++;
						}
						else
						{
							System.out.println("答案错误,正确答案为:" + x + "/" + y + "=" + (x + y));
						}
						i ++;
						sum1 ++;
					
					}
				}
				
				break;
			case 5:
				System.out.println("总题数：" + sum1  + "答对的题数:" + sum2);
				System.out.println("系统已退出,欢迎下次使用");
				System.exit(0);
				break;
				
			default:
				
				System.out.println("选择错误。请重新选择");
			
			
			
			}
		}
		
		

		}
		else
		{
			System.out.println("密码输入错误");
			
		}
		i ++;
		}
		System.out.println("密码错误三次。请明天再来");
	}

}