第一个Java文件：  import java.util.Scanner;     public class GameA_B {   public static void main(String[] args) {        Scanner reader=new Scanner(System.in);         int area;          System.out.println("Game Start…………Please enter the area:(1-9)" +       '\n'+"1,2,3 means easy"+'\n'+"4,5,6 means middle"+'\n'+         "7,8,9 means hard"+'\n'+"Please choose:");       area=reader.nextInt();      switch((area-1)/3)      {       case 0:System.out.println("You choose easy! ");break;      case 1:System.out.println("You choose middle! ");break;      case 2:System.out.println("You choose hard! ");break;      }       System.out.println("Good Luck!");       GameProcess game1=new GameProcess(area);         game1.process();  }   }    第二个Java文件：  import java.util.Random; import java.util.Scanner;  

  public class GameProcess {  int area,i,arrcount,right,midright,t;   int base[]=new int[arrcount],userNum[]=new int[area],sysNum[]=new int[area];    Random random=new Random();     Scanner reader=new Scanner(System.in);  GameProcess(int a)  {   area=a;   arrcount=10;     right=0;