Java Code House

import java.util.Scanner;
import java.util.Stack;

public class PostfixToInfix {
 
 /**
  * Checks if the input is operator or not
  * @param c input to be checked
  * @return true if operator
  */
 private boolean isOperator(char c){
  if(c == '+' || c == '-' || c == '*' || c =='/' || c == '^')
   return true;
  return false;
 }
 
 /**
  * Converts any postfix to infix
  * @param postfix String expression to be converted
  * @return String infix expression produced
  */
 public String convert(String postfix){
  Stack<String> s = new Stack<>();
  
  for(int i = 0; i < postfix.length(); i++){
   char c = postfix.charAt(i);
   if(isOperator(c)){
    String b = s.pop();
    String a = s.pop();
    s.push("("+a+c+b+")");
   }
   else
    s.push(""+c);
  }
  
  return s.pop();
 }
 
 public static void main(String[] args) {
  PostfixToInfix obj = new PostfixToInfix();
  Scanner sc =new Scanner(System.in);
  System.out.print("Postfix : ");
  String postfix = sc.next();
  System.out.println("Infix : "+obj.convert(postfix));
 }
}

Postfix : ABC^^
Infix : (A^(B^C))