Java中报错No enclosing instance of type caiquan is accessible. Must qualify the allocation with an enclosing instance of type caiquan (e.g. x.new A() where x is an instance of caiquan).

package test;
import java.util.Scanner;
import java.util.Random;
public class caiquan {
public static void main(String[] args){
Game g=new Game();
g.begin();
}

//将这个类定义为静态就好了，也就说改成 static class Game
class Game{
public void begin(){
System.out.println("********************");
System.out.println("A finger-guessing game");
System.out.println("********************");
System.out.println("Start game（1/0）");
Scanner input = new Scanner(System.in);
int result = input.nextInt();
if(result==1){
System.out.println("请输入猜拳次数：");
int num = input.nextInt();
play(num);
}else{
System.out.println("Go Fuck Yourself!");
}
}
public void play(int num){
int userScore=0;//人赢的次数
int pcScore=0;//pc赢的次数
Random r = new Random();
Scanner input = new Scanner(System.in);
while(num>0){
int x = r.nextInt(100)%3+1;
System.out.println("请输入（1，剪刀 2,石头 3,布）");
int s = input.nextInt();

if(s>=4||s==0){
System.out.println("瓜娃子看不懂嗦，只能输入1,2,3！");
}

if(s==1){
switch(x){
case 1:
System.out.println("平局，你出剪刀，电脑出剪刀");
case 2:
System.out.println("你输了，你出剪刀，电脑出石头");
pcScore++;
case 3:
System.out.println("你赢了，你出剪刀，电脑出布");
userScore++;
}
}
if(s==2){
switch(x){
case 1:
System.out.println("你赢了，你出石头，电脑出剪刀");
userScore++;
break;
case 2:
System.out.println("平局，你出石头，电脑出石头");
break;
case 3:
System.out.println("你输了，你出石头，电脑出布");
pcScore++;
break;
}
}
if(s==3){
switch(x){
case 1:
System.out.println("你输了，你出布，电脑出剪刀");
pcScore++;
break;
case 2:
System.out.println("你赢了，你出布，电脑出石头");
userScore++;
break;
case 3:
System.out.println("平局，你出布，电脑出布");
break;
}
}
num--;
}
System.out.println("**************");
System.out.println("你赢了："+userScore+"次！");
System.out.println("电脑赢了："+pcScore+"次！");
if(userScore==pcScore){
System.out.println("平局！");
}else if(userScore>pcScore){
System.out.println("你赢了！");
}else{
System.out.println("电脑赢了！");
}
}
}
}

//在Java中，类中的静态方法不能直接调用动态方法。只有将某个内部类修饰为静态类，然后才能够在静态类中调用该类的成员变量与成员方法