This question is for \" Data Structure course \". ( check the image below ) I pr

ID: 3812225 • Letter: T

Question

This question is for "Data Structure course". (check the image below)

I prefer a brief answer & If you are going to use any programming language to solve this problem, then use JAVA language.

** Please don't provide a handwritten solution or a picture of the solution. Just post the answer here so I can read it easily.

Expression: a * - b + c

Problem 4 Write the postfix form of the infix expression below. Then describe how each token is processed to generate postfix expression out by using stack expression a b c

Explanation / Answer

Hi, Pleqase find my implementation.

Please let me know inn case of any issue.

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.util.Stack;

public class InfixToPostfixConverter {

public String convert(char[] infix)

// converts an infix expression to postfix

{

Stack<Character> operators = new Stack<Character>();

char symbol;

String postfix = "";

for (int i = 0; i < infix.length; ++i)

// while there is input to be read

{

symbol = infix[i];

// if it's an operand, add it to the string

if (Character.isLetter(symbol) || Character.isDigit(symbol))

postfix = postfix + symbol;

else if (symbol == '(')

// push (

{

operators.push(symbol);

} else if (symbol == ')')

// push everything back to (

{

while (operators.peek() != '(') {

postfix = postfix + operators.pop();

}

operators.pop(); // remove '('

} else

// print operators occurring before it that have greater precedence

{

while (!operators.isEmpty() && !(operators.peek() == '(')

&& prec(symbol) <= prec(operators.peek()))

postfix = postfix + operators.pop();

operators.push(symbol);

}

while (!operators.isEmpty())

postfix = postfix + operators.pop();

return postfix;

}

public int prec(char x) {

if (x == '+' || x == '-')

return 1;

if (x == '*' || x == '/' || x == '%')

return 2;

return 0;

}

// main method

public static void main(String[] args)throws IOException

{

// declaring object

//PostfixEvaluator postfixEval = new PostfixEvaluator();

InfixToPostfixConverter infixToPostfix = new InfixToPostfixConverter();

System.out.println("Reading from in.dat file");

String input;

FileReader isr = new FileReader("in.dat");

BufferedReader br = new BufferedReader(isr);

FileWriter fr = new FileWriter("post.dat");

BufferedWriter bw = new BufferedWriter(fr);

while(true)

{

//System.out.println("Enter the Infix expresion(of enter Q/q to stop)");

input = br.readLine();

//input=getString();

if(input.equalsIgnoreCase("q"))

break;

char[] infix = input.trim().toCharArray();

String postfix = infixToPostfix.convert(infix);

bw.write(postfix);

bw.newLine();

//System.out.println("Postfix Expression:- "+postfix);

}

System.out.println("Successfully written in post.dat");

}

Sample run: