我需要它以一种不需要任何空间的方式运行

Question

我需要这个程序才能运行而不需要在每个字符之间留出任何空格。如右图所示，如果在输入的每个字符之间存在空格，则此代码将计算表达式，我需要它运行以便它将在没有或带空格的情况下运行。谢谢

public class InfixEval {

Stack<String> operandsStk; //for operands
Stack<Character> operatorsStk;//for operators +,-,*,/,(,)
InfixEval()
{
     //instantiate the stacks
     operandsStk=new Stack<String>();
     operatorsStk=new Stack<Character>();
}
//evaluates and returns the result
public int evaluate(String exp) throws ArithmeticException
{
     boolean fail=false;
     try
     {
         //tokenize the expression
     String tokens[]=exp.split("");
     for(int i=0;i<tokens.length;i++)
     {
         //if it is an operand push it onto the operand stack
         if(!tokens[i].equals("+")&& !tokens[i].equals("*")&&!tokens[i].equals("-")
                   &&!tokens[i].equals("/") && !tokens[i].equals("(")&&!tokens[i].equals(")"))
         {
              operandsStk.push(tokens[i]);
         }
         //if it is a left parenthesis
         else if(tokens[i].equals("("))
         {
              //push it onto the operator stack
              operatorsStk.push((Character)tokens[i].charAt(0));
         }
         //it is a right parenthesis
         else if(tokens[i].equals(")"))
         {
              //while top of the operator stack is not a left parenthesis   
              while(operatorsStk.peek()!='(')
              {
                   // pop two operands and an operator
                   int x=Integer.parseInt(operandsStk.pop());
                   int y=Integer.parseInt(operandsStk.pop());
                   char opr=operatorsStk.pop();
                   //    perform the calculation   
                   int result=0;
                   if (opr=='+')
                   {
                        result= y+x;
                        //push the result onto the operand stack    
                        operandsStk.push(result+"");
                   }
                   else if(opr=='-')
                   {
                        result= y-x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
                   else if(opr=='*')
                   {
                        result= y*x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
                   else if(opr=='/')
                   {   
                        result=y/x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }

              }
              //pop top of the operator stack and ignore it
              operatorsStk.pop();
         }
         //if it is an operator
         else if(tokens[i].equals("+")||tokens[i].equals("-")
                   ||tokens[i].equals("*")||tokens[i].equals("/"))
         {
              //while the operator stack is not empty and         
              //the operator at the top of the stack has higher
              //or the same precedence than the current operator
              while(!operatorsStk.empty()&&hasHigherPrecedence(operatorsStk.peek(),tokens[i].charAt(0)))
              {
                   //pop two operands
                   int x=Integer.parseInt(operandsStk.pop());
                   int y=Integer.parseInt(operandsStk.pop());
                   char opr=operatorsStk.pop();
                   //perform the calculation   
                   int result=0;
                   if (opr=='+')
                   {
                        result= y+x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
                   else if(opr=='-')
                   {
                        result= y-x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
                   else if(opr=='*')
                   {
                        result= y*x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
                   else if(opr=='/')
                   {   
                        result=y/x;
                        //push the result onto the operand stack
                        operandsStk.push(result+"");
                   }
              }

              operatorsStk.push(tokens[i].charAt(0));
         }
     }
     //while the operator stack is not empty
     while(!operatorsStk.empty())
     {
         // pop two operands and an operator
         int x=Integer.parseInt(operandsStk.pop());
         int y=Integer.parseInt(operandsStk.pop());
         char opr=operatorsStk.pop();
         //perform the calculation
         int result=0;
         if (opr=='+')
         {
              result= y+x;
              // push the result onto the operand stack
              operandsStk.push(result+"");
         }
         else if(opr=='-')
         {
              result= y-x;
              // push the result onto the operand stack
              operandsStk.push(result+"");
         }
         else if(opr=='*')
         {
              result= y*x;
              // push the result onto the operand stack
              operandsStk.push(result+"");
         }
         else if(opr=='/')
         {   
              result=y/x;
              // push the result onto the operand stack
              operandsStk.push(result+"");
         }
     }
     }
     catch(EmptyStackException e)
     {        
         //if an error occurs
         fail=true;
     }
     if(fail==false)
         //the final result is at the top of the operand stack and return it
         return Integer.parseInt(operandsStk.pop());
     else
         return -1;
}
//returns true, if the top has high precedence than current
boolean hasHigherPrecedence(char top, char current)
{
     int topPre=-1;
     int curPre=-1;
     if(top == '+' || top == '-')
     {
         topPre=0;
     }
     if(top == '*' || top == '/' || top== '%')
     {
         topPre=1;
     }
     if(current == '+' || current == '-')
     {
         curPre=0;
     }
     if(current == '*' || current == '/' )
     {
         curPre=1;
     }
     if(topPre>=curPre)
         return true;
     else
         return false;
}


}

Answer 1

仔细看看这一行：

String tokens[]=exp.split("");

您使用什么定界符将行拆分为标记？