我正在尝试创建一个java类，允许用户在放入计算器的标记时放入空格，然后将其转换为后缀。
但它没有提供正确的输出。例如，对于输入1+2，输出应为12+，但为12。
import java.util.*;
public class Infix
{
Stack loco = new Stack();
//create a scanner
//now to create a stack
public String Prefix(String gordo)
{
//Here is where the Program Begin
//type the the regular expression
String[] red;
red=gordo.split("(?=[()+\\-*/])|(?<=[()+\\-*/])"); //tokenize the string include delimiter
System.out.println("THE EXPRESSION IN INFIX IS");
for(int k=0;i<red.length;k++)
{
red[i]=red[i].trim(); //remove white spaces
}
//now we will test out if what is stored is digit or character
System.out.println("BREAKING IT ALL DOWN INTO A STRING OF CHARACTERS");
String ramon;
char[] c; //an array of characters
char feo; // a single character
String post=""; //this is where the post fix expression will be put in
for(int i=0;i<red.length;i++)
{
ramon=red[i];
c=ramon.toCharArray();
for(int j=0;j<c.length;j++)
{
System.out.println(c[j]); //print what is stored in C
feo=c[j];
if(Character.isLetterOrDigit(feo) == true)
{
post=post+feo; //add character to string to post fix
}
else if( feo == '(' )
{
loco.push(feo);
}
else if( feo == ')')
{
char look;
while((look = LookAt()) != '(')
{
post=post+look; //add it all in there
PopIt();
}
}
//this does the associtivity and the operator precdence
//if the operator is lower or equal to the precedence change
//the current operand pop it from stack and put it into output
//string
else
{
while(LaPrio(feo) <= LaPrio(LookAt()))
{
post=post+LookAt();
PopIt();
}
}
}
}
System.out.println("THIS IS THE POSTFIX EXPRESSION");
return post;
}
//this will determine operator precedence
private int LaPrio(char operator)
{
if(operator == '/' || operator == '*' || operator == '%')
{
return 2;
}
if(operator == '+' || operator == '-')
{
return 1;
}
return 0;
}
//this will do the see what is one top of the stack
private Character LookAt()
{
if( !loco.empty() == false) //if there no items it will return false plus ! make it true
{
return(Character) loco.peek();
}
else
return 0;
}
private void PopIt()
{
if(!loco.empty())
{
loco.pop();
}
}
}