Project $1$

Logic $$ Evaluating Logical Expressions

Total $100$ pts$.$

Write a program that will evaluate a logical expression $($compound proposition$)$ based on the

given truth values of individual propositional variables. A logical expression may include the

logical AND $(/\backslash ),$ logical OR $(\backslash /),$ and logical NOT $($~$)$ operators.

Here is an example of a logical expression using proper notation:

a $$ b $$c $$ d

This expression will need to be input as the following in this program to accommodate simple

keyboard input:

a $/\backslash$ b $\backslash /$ ~c or d

Note that the logical AND and logical OR operators are input using the keys $/$ and $\backslash$ on your

keyboard. These symbols use two keys on your keyboard with no space in between. Also note

that there is no space between the logical NOT operator and the variable that it is attached to$.$

There needs to be a space included between a variable and the other operators.

The logical operators will be evaluated left to right in the order of precedence of the operators.

Parentheses will not be included. Check Zybook section $1\mathrm{.}2$ for details.

Input

Your program should take as input the following information:

$$ number of variables in an expression, between $1$ and $5$

$$ the truth values of each of these variables

$$ a logical expression involving these variables and logical operators

Code

Your program should allow the user to interact via the keyboard. There is no need for any file

input. Your program should guide the user if they provide incorrect input instead of stopping or

crashing.

Your program should adhere to the following programming guidelines:

$$ Use proper naming conventions, such as upper case for constants, lower case for

variables, and title case for classes.

$$ Use proper formatting, such as tabs$,$ spaces, line breaks, and curly braces.

$$ Display good documentation, such as$,$ a header block for each file and and inline

comments, as needed.

$$ Display good design, such as$,$ decomposition of tasks and modular code.

$$ Should be no more complex than necessary, for example, if a task can be accomplished

by a single loop, it should not be programmed with a $3-$way nested loop.

$$ Satisfy all the requirements specified in this document.

COSC $314$ Project $12$

Output

A sample program output is given below. User input is displayed in green font.

Logical Expressions Evaluator

$-----------------------------$

Enter the number of variables in the expression: $4$

Enter the values of variables $-$ true or false:

a: true

b: false

c: true

d: false

Enter the logical expression:

c $/\backslash$ ~d $\backslash /$ a $\backslash /$ b

The value of the given logical expression is true.

Below is a program output including errors in user input. Your program should not crash.

Logical Expressions Evaluator

$-----------------------------$

Enter the number of variables in the expression: $2$

Enter the values of variables $-$ true or false:

a: one

Invalid value. Enter true of false.

true

b: false

Enter the logical expression:

a $/\backslash$ d

Invalid expression. Enter again.

a $/\backslash$ b

The value of the given logical expression is false.

Test cases

$1.$ Variables $(4)$: a $=$ true, b $=$ false, c $=$ true, d $=$ false

Expression: c $/\backslash$ ~d $\backslash /$ a $\backslash /$ b

$2.$ Variables $(3)$: a $=$ false, b $=$ false, c $=$ true

Expression: ~a $/\backslash$ ~b $/\backslash$ c

$3.$ Variables $(5)$: a $=$ false, b $=$ false, c $=$ true, d $=$ true, e $=$ false

Expression: c $/\backslash$ e $/\backslash$ b $/\backslash$ ~a $\backslash /$ d