computeexpression.java

用java语言实现了二十四点游戏的源代码

package TwentyFourdot;
import java.lang.*;
import java.util.*;
public class ComputeExpression{
    //private String expression,subexpression;
    private int i,result,flag;
    private int[] start , end;
    public double cal(Object oper,double l,double k){
    	if (oper.equals("+"))
    	l+=k;
    	else if (oper.equals("-"))
    	l-=k;
    	else if (oper.equals("*"))
    	l = l*k;
    	else if (oper.equals("/"))
    	l = l/k;
    	return l; 
    	}
    public double calculate(String expression){
    	StringTokenizer strtoken = new StringTokenizer(expression ,"+-*/()",true);
    	String strElement = new String();
    	Hashtable hsOperator = new Hashtable(); //创建一个哈希表用来控制运算优先级       
    	hsOperator.put("+", new Integer(1));
    	hsOperator.put("-", new Integer(1));        
    	hsOperator.put("*", new Integer(2));        
    	hsOperator.put("/", new Integer(2));        
    	hsOperator.put("(", new Integer(3));        
    	hsOperator.put(")", new Integer(0));
    	while(strtoken.hasMoreElements())
    	{
    	    strElement = strTok.nextToken();
    	}
    	}
    /*public ComputeExpression(String s){
    	expression = s;
    	if (expression.length()<7&&expression.length()>9)
    	{
    		System.out.println("please input right expression!");
    	}
    	}
    public String getExpression(){
    	return expression;
    	}
    public int compute(){
    	flag = 0;
    	start = new int[3];
    	end = new int[3];
    	for (i = 0;i<expression.length();i++)
    	{
    		if (expression.toCharArray()[i] == "*".charAt(0)&&expression.toCharArray()[i]=="/".charAt(0))
    		{
    			flag = flag + 1;
    			start[flag-1] = i - 1;
    			end[flag-1] = i + 1;
    		}
    	}
    	switch(flag)
    	{
    		case 0;
    		break;
    		case 1;
    			
    	}*/
}