后缀表达式求值

package expr;

import java.util.Scanner;

import linkStack.LinkStack;

/**
* 任务三：栈的应用--后缀表达式求值
阅读教材及有关参考书。
（1）利用任务一中实现的栈（SeqStack或者LinkStack），实现一位数字的整型后缀表达式求值程序，编写主函数测试算法正确性。
（2）利用任务一中实现的栈（SeqStack或者LinkStack），实现实数（带小数点，位数不限）的后缀表达式求值程序，编写主函数测试算法正确性。
* @author asus
*
*/
public class ExprDemo2 {
static LinkStack<Character> s=new LinkStack<Character>();
static LinkStack<Double> s1=new LinkStack<Double>();
public static void main(String args[]){
Scanner sc=new Scanner(System.in);

System.out.println("请输入要求值的表达式：");
String str=sc.nextLine();
System.out.println(str);
s.add('#');
String pstr=transformz(str);
System.out.println(pstr);
double result=Calcu(pstr);
System.out.println(result);//12*(3+61)/8
}
public static String transformz(String str)
{
String pstr="";
for(int i=0;i<str.length();i++){
char c=str.charAt(i);
if((c>='0' && c<='9') || c=='.'){
pstr=pstr+c;
continue;
}
pstr=pstr+" ";
if(c=='(')
s.push(c);
else if(c==')'){
while(s.getTop()!='(')
{
pstr+=s.pop();
}
s.pop();
}
else if(c=='+' || c=='-' || c=='*' || c=='/' || c=='%' || c=='^' )
{
char operator=s.getTop();
while(Tokenpriority(c)<=Stackpriority(operator))
{
pstr=pstr+operator;
s.pop();
operator=s.getTop();
}
s.push(c);
}

}
while(!s.isEmpty())
pstr+=s.pop();
return pstr.substring(0, pstr.length()-1);
}
private static int Tokenpriority(char operator) {
if(operator=='+' || operator=='-')
return 1;
if(operator=='*' || operator=='/' || operator=='%')
return 2;
if(operator=='^')
return 4;
if(operator=='(')
return 5;
return -1;
}
private static int Stackpriority(char operator) {
if(operator=='+' || operator=='-')
return 1;
if(operator=='*' || operator=='/' || operator=='%')
return 2;
if(operator=='^')
return 3;
if(operator=='(')
return 0;
return -1;
}
public static Double Calcu(String str)
{
String pstr2="";
for(int i=0;i<str.length();i++)
{
char  c=str.charAt(i);

if((c>='0' && c<='9') || c=='.')
{
pstr2=pstr2+c;
continue;
}
if(pstr2.length()>0){
Double n=Double.parseDouble(pstr2);
s1.push(n.doubleValue());
}

if(c=='+' || c=='-' || c=='*' || c=='/' || c=='%' || c=='^' ){
Double a=s1.pop();
Double b=s1.pop();
if(c=='+')
s1.push(b+a);
if(c=='-')
s1.push(b-a);
if(c=='*')
s1.push(b*a);
if(c=='/')
s1.push(b/a);
}
pstr2="";
}
return s1.pop();
}
}
//12.99289*(33.33+61)/8.3222