Question: import java.util.EmptyStackException; import java.util.Stack; public class Arithmetic { private Stack stk; private int length; String expression; public Arithmetic(String expression) { stk = new Stack ();

import java.util.EmptyStackException;

import java.util.Stack;

public class Arithmetic { private Stack stk; private int length; String expression; public Arithmetic(String expression) { stk = new Stack(); this.expression = expression; this.length = expression.length(); } // Determine if parentheses are balanced boolean isBalance() { int index = 0; boolean fail = false; try { while (index < length && !fail) { char ch = expression.charAt(index); switch (ch) { case Constants.LEFT_NORMAL: stk.push(new Character(ch)); break; case Constants.RIGHT_NORMAL: stk.pop(); break; default: break; }//end of swtich index++; }//end of while }//end of try catch (EmptyStackException e) { System.out.println(e.toString()); fail = true; } if (stk.empty() && !fail) return true; else return false; } }

class RPN { public static void main(String[] arg) { String s[] = {"5 + ) * ( 2", " 2 + ( - 3 * 5 ) ", "(( 2 + 3 ) * 5 ) * 8 ", "5 * 10 + ( 15 - 20 ) ) - 25", " 5 + ( 5 * 10 + ( 15 - 20 ) - 25 ) * 9" }; for (int i = 0; i < s.length; i++) {

Arithmetic a = new Arithmetic(s[i]); if (a.isBalance()) { System.out.println("Expression " + s[i] + " is balanced "); a.postfixExpression(); System.out.println("The post fixed expression is " + a.getPostfix()); a.evaluateRPN(); // Supply the necessary codes to determine the validity of your answers } else System.out.println("Expression is not balanced "); } } }

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

class Arithmetic { Stack stk; String expression, postfix; int length;

Arithmetic(String s) { expression = s; postfix =""; length = expression.length(); stk = new Stack(); } // Validate the expression - make sure parentheses are balanced boolean isBalance() { // Already defined }

// Convert expression to postfix notation void postfixExpression() { stk.clear(); // Re-using the stack object Scanner scan = new Scanner(expression); char current; // The algorithm for doing the conversion.... Follow the bullets while (scan.hasNext()) { String token = scan.next();

if (isNumber(token)) // Bullet # 1 postfix = postfix + token + " "; else { current = token.charAt(0);

if (isParentheses(current)) // Bullet # 2 begins { if(stk.empty() || current == Constants.LEFT_NORMAL) {

// push this element on the stack; } else if (current == Constants.RIGHT_NORMAL) { try { /* Some details ... whatever is popped from the * stack is an object, hence you must cast this * object to its proper type, then extract its * primitive data (type) value. */ Character ch = (Character)stk.pop(); char top = ch.charValue();

while (top != Constants.LEFT_NORMAL) { /* Append token popped onto the output string * Place at least one blank space between * each token */ } } catch(EmptyStackException e) {

} } }// Bullet # 2 ends else if (isOperator(current))// Bullet # 3 begins { if(stk.empty()) stk.push(new Character(current)); else { try { // Remember the method peek simply looks at the top // element on the stack, but does not remove it.

char top = (Character)stk.peek(); boolean higher = hasHigherPrecedence(top, current);

while(top != Constants.LEFT_NORMAL && higher) { postfix = postfix + stk.pop() + " "; top = (Character)stk.peek(); } stk.push(new Character(current)); } catch(EmptyStackException e) { stk.push(new Character(current)); } } }// Bullet # 3 ends } } // Outer loop ends

try { while(!stk.empty()) // Bullet # 4 ; // complete this } catch(EmptyStackException e) {

} }

boolean isNumber(String str) { //define this method }

boolean isParentheses(char current) { // define this method; }

boolean isOperator(char ch) { // define this method }

boolean hasHigherPrecedence(char top, char current) { // define this method }

String getPostfix() { // define method } }

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Databases Questions!

Q:

// here is my attempt at implementing a RPN calculator. I can't figure out why it is throwing exceptions when it shouldn't be. // for example if the string is String[] e1 = {"1", "1", "+"}; // the...

Q:

I need help with the following problem. ArrayStack.java, LinkedStack.java, and EvaluateDemonstration.java are at the bottom. For part c, ignore the "check your answers from problem #2." Please make...

Q:

import java.util.Stack; import java.util.StringTokenizer; public class Evaluator { private Stack operandStack; private Stack operatorStack; private StringTokenizer tokenizer; private static final...

Q:

package edu.csc413.calculator.evaluator; import edu.csc413.calculator.exceptions.InvalidTokenException; import edu.csc413.calculator.operators.*; import java.util.Stack; import...

Q:

We will be creating and using a stack ADT (Abstract Data Type) to be used with a simple calculator. Our calculator will be capable of evaluating the following simple expression: 2.3 * 1.2 + 14.0 The...

Q:

Please, don't copy-paste the answer that's already on chegg. It didn't work/run. Thanks. EVALUATOR: import java.util.*; public class Evaluator { private Stack operandStack; private Stack...

Q:

Consider simple infix expressions that consist of single-digit operands; +,-,*,%, and/; and parentheses. Assume that unary operators are illegal and that the expression contains no embedded spaces....

Q:

EVALUATOR: import java.util.*; public class Evaluator { private Stack operandStack; private Stack operatorStack; private StringTokenizer tokenizer; private static final String DELIMITERS = "+-*^/()...

Q:

We will be creating and using a stack ADT to be used with a simple calculator. Our calculator will be capable of evaluating the following simple expression: 2.3 * 1.2 + 14.0 The operators for our...

Q:

**********Evaluator.java**************** package evaluator; import java.util.*; import operand.Operand; import operator.Operator; public class Evaluator { private Stack operandStack; private Stack...

Q:

WYZ Ltd. is a manufacturing company incorporated in Ghana under the Companies Act of 2019, Act 992. After successfully conducting their external and internal audits, the company formulated and...

Q:

Three mutually exclusive alternatives are being evaluated, and their costs and revenues are listed in Table P6-1. (6.4) a. If the MARR is 20% per year and the analysis period is 10 years, use the PW...

Q:

1. A customer says that his car should not start unless the clutch has been pressed. Should it be considered as a valid customer need? Justify your answer.

Q:

Seved Help 14 Wisconsin Snowmobile Corp. is considering a switch to level production Cost efficiencies would occur under level production, and aftertax costs would decline by $31,500, but inventory...

Q:

=+ c. a company president deciding whether to open a new factory

Q:

=+ b. a member of Congress deciding how much to spend on national parks

Q:

=+ 2. You are trying to decide whether to take a vacation. Most of the costs of the vacation (airfare, hotel, and forgone wages) are measured in dollars, but the benefits of the vacation are...