java实现24点游戏

24点游戏是经典的纸牌益智游戏。
常见游戏规则：
从扑克中每次取出4张牌。使用加减乘除，第一个能得出24者为赢。（其中，J代表11，Q代表12，K代表13，A代表1），按照要求编程解决24点游戏。
用户初始生命值为一给定值（比如3），初始分数为0。随机生成4个代表扑克牌牌面的数字或字母，由用户输入包含这4个数字或字母的运算表达式（可包含括号），如果表达式计算结果为24则代表用户赢了此局。

import java.util.*;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

public class th {
	private double[] poker = new double[4];
	private int lives = 3;	//生命值
	private int score = 0;	//分数
	private final char [] symbol = {'1', '1', '2', '3', '4', '5', '6', '7',
			'8', '9', '0', 'J', 'Q', 'K'};	//显示牌面数组
	private String answer = new String();
	public static String playerName = new String();
	
	//随机生成4个在1~13内的数字
	public void randomPoker()
	{
		int i = 0;
		while(i != 4)
		{
			poker[i] = (int)(Math.random()*14);
			if(poker[i] != 0)	//判断生成的数字为0跳出本次循环
				i++;
			else 
				continue;
		}
	}
	
	//数字对应牌名输出
	public void showPoker()
	{
		System.out.println("随机四张牌为：");
		for(int i = 0; i < 4; i++)
		{
			if(poker[i] == 10)
				System.out.print("10  ");
			else
				System.out.print(symbol[(int)poker[i]] + "  ");
		}
	}
	
	
	//判断运算符优先级
	public static int getValue(String op)
	{
		int result;
        switch (op)
        {
            case "+":
                result=1;
                break;
            case "-":
                result=1;
                break;
            case "*":
                result=2;
                break;
            case "/":
                result=2;
                break;
            default:
//                System.out.println("不存在该运算符");
                result=0;
        }
        return result;
    }

	
	 public static List<String> toInfixExpression(String s) 
	 {
	        List<String> ls = new ArrayList<String>();//存储中序表达式
	        int i = 0;
	        String str;
	        char c;
	        do 
	        {
	            if ((c = s.charAt(i)) < 48 || (c = s.charAt(i)) > 57) 
	            {
	                ls.add("" + c);
	                i++;
	            } else {
	                str = "";
	                while (i < s.length() && (c = s.charAt(i)) >= 48
	                        && (c = s.charAt(i)) <= 57) 
	                {
	                    str += c;
	                    i++;
	                }
	                ls.add(str);
	            }

	        } while (i < s.length());
	        Stack<String> s1=new Stack<String>();
	        List<String> lss = new ArrayList<String>();
	        for (String ss : ls) 
	        {
	            if (ss.matches("\\d+"))
	            {
	                lss.add(ss);
	            } 
	            else if (ss.equals("("))
	            {
	                s1.push(ss);
	            } 
	            else if (ss.equals(")"))
	            {

	                while (!s1.peek().equals("(")) 
	                {
	                    lss.add(s1.pop());
	                }
	                s1.pop();
	            } 
	            else 
	            {
	                while (s1.size() != 0 && getValue(s1.peek()) >= getValue(ss)) 
	                {
	                    lss.add(s1.pop());
	                }
	                s1.push(ss);
	            }
	        }
	        while (s1.size() != 0) {
	            lss.add(s1.pop());
	        }
	        return lss;
	    }

	    public static int calculate(List<String> ls) 
	    {
	        Stack<String> s=new Stack<String>();
	        for (String str : ls) 
	        {
	            if (str.matches("\\d+")) 
	            {
	                s.push(str);
	            } 
	            else 
	            {
	                int b = Integer.parseInt(s.pop());
	                int a = Integer.parseInt(s.pop());
	                int result=0;
	                if (str.equals("+")) 
	                {
	                    result = a + b;
	                } 
	                else if (str.equals("-")) 
	                {
	                    result = a - b;
	                } 
	                else if (str.equals("*")) 
	                {
	                    result = a * b;
	                } 
	                else if (str.equals("\\")) 
	                {
	                    result = a / b;
	                }
	                s.push("" + result);
	            }
	        }
	       // System.out.println(s.peek());
	        return Integer.parseInt(s.pop());
	    }
	
	//判断玩家输入运算式结果是否为24
	public boolean judge(String a)
	{
	        String rpnStr="";
	        for(String str:toInfixExpression(answer))
	        {
	            rpnStr+=str;
	        }
        if(calculate(toInfixExpression(answer)) == 24)
        	return true;
        else
        	return false;
	}
	
	//判断生成4个数有无运算出24的可能
	public boolean pokerJudge(double[]a, int n)
	{
		double[] b = new double [5];
		//当数组a里面的元素只剩一个的时候 对a[0]进行判断 
		if(n == 1)
		{
			if((a[0] - 24) <=1e-6 && (a[0] - 24) >= (1e-6) * -1.0)
				return true;
			else 
			    return false;
		}
		else
		{
			for(int i = 0; i < n-1; i++)
			{   //任选两数进行枚举 
				for(int j = i+1; j < n; j++)
				{
					int m = 0;
					for(int k = 0;k < n;k++)
					{
						if(k != i && k != j)   b[m++] = a[k];  //将剩余的数放入b数组 
					}
					b[m] = a[i] + a[j] ; //将两数加进行递归 
					if(pokerJudge(b,m+1))   
					      return true;
					b[m] = a[i] - a[j] ; //将两数差进行递归 
				    if(pokerJudge(b,m+1))
					      return true;
					b[m] = a[j] - a[i] ; //将两数差进行递归 
					if(pokerJudge(b,m+1))   
					      return true;
					b[m] = a[j] * a[i] ; //将两数积进行递归 
					if(pokerJudge(b,m+1))  
					      return true;
		            if(a[i] != 0)
		            {      //将两数商进行递归 
		            	b[m] = a[j]/a[i];
		            	if(pokerJudge(b,m+1))   return true;
		            }	
					if(a[j] != 0)
					{     //将两数商进行递归 
		            	b[m] = a[i]/a[j];
		            	if(pokerJudge(b,m+1))   return true;
		            }		 
				}
			}
		}
		return false ;
	}
	
	public void play()
	{
		Scanner getAnswer = new Scanner(System.in);
		while(lives != 0)
		{
			randomPoker();
			if(pokerJudge(poker, 4))
			{
				showPoker();
				System.out.println("输入你的答案");
				answer = getAnswer.nextLine();
				if(judge(answer))
				{
					score += 10;
					System.out.println("回答正确");
					System.out.println("当前分数" + score);
				}
				else
				{
					lives--;
					System.out.println("回答错误，还有" + lives + "生命值");
				}
			}
			else
				continue;
		}
		System.out.println("游戏结束，分数已保存");
		File file = new File("D:/TopList.txt");
		FileWriter fw = null;
		try {
		//如果文件存在，则追加内容；如果文件不存在，则创建文件
		File f=new File("D:\\TopList.txt");
		fw = new FileWriter(f, true);
		} catch (IOException e) {
		e.printStackTrace();
		}
		PrintWriter pw = new PrintWriter(fw);
		pw.println("玩家姓名  " + playerName + " 成绩 " + score);
		pw.flush();
		try {
		fw.flush();
		pw.close();
		fw.close();
		} catch (IOException e) {
		e.printStackTrace();
		}
	}
	
	public void replay() 
	{
		lives = 3;
		score = 0;
	}
	
	public static void main(String[] args)
	{
		th Game = new th();
		Scanner getName = new Scanner(System.in);
		while(true)
		{
			System.out.println("请输入玩家姓名：");
			th.playerName = getName.nextLine();
			Game.play();
			Game.replay();
		}
		
		//Game.outPut();
	}
}