In this lab, you'll implement a simple calculator and equation converter. It'll

parse expressions written in $[$reverse Polish notation$][$rpn$].$ Then, depending on

a command line argument, it will do one of the following:

Print the expression in $[$Polish notation$][$pn$].$

Print the expression in reverse Polish notation.

Evaluate the expression and print the result.

Your calculator should operate on 'double's and support the following operators.

$"+$ adds two numbers $(34+$ is $).$

$"-"$ subtracts one number from another $($ is $-4^{\text{'}}).$

$"*"$ multiplies two numbers $(27*{*}^2$ is $\text{'}{14}^{\text{'}}).$

$"$ divides one number by another $(7-\frac{4}{?}$ is $\{$:${?}^{\text{'}}-1\mathrm{.}75).$

$\text{'}\%{?}^{\text{'}}$ returns the remainder after dividing one number by another $(0\mathrm{.}70\mathrm{.}3\%$ is $\text{'}{0\mathrm{.}1}^{\text{'}}).$

$$ negates a single number $(8$ is ${?}^{\text{'}}-8^{\text{'}}).$

Your calculator should read one line of input at a time, print some output, then

move on to the next line. It should exit when it reaches the end of the input.

Use $\text{'}$Ctrl$+$D$\text{'}$ to simulate this on Mac and Linux, or $"$Ctrl $1+Z\text{'}$ followed by "Enter'

on Windows.

Definitions

All the following examples are representations of this equation, written here in

standard $($infix$)$ notation. It evaluates to $67\mathrm{.}5.$

$(12+3)**(\frac{5+4}{2})$

Polish Notation

In Polish notation, also known as prefix notation, the operator comes before its

arguments.

$**+\frac{123}{+}542$

In reverse Polish notation, also known as postfix notation, the operator comes

after its arguments.