Assignment $3$ will use code from assignment $2$ to encrypt and decrypt a plaintext $($p$)$ string of characters,

the digits $0-9$ and two special characters, a question mark $?$ and a square bracket $].$ The plaintext will

not contain spaces or other characters $($e$.$g$.$@$,*,$etc.$).$ New to assignment $3$ will be the use of functions,

array parameters and file input$/$output $($I$/$O$),$ including two user$-$defined functions named encrypt and

decrypt described in this handout. For file I$/$O the commmand line arguments from Assignment $2$ will

be stored in a configuration file and the name of the configuration file will be the only command line

argument for Assignment $3.$

For this assignment, the encryption and decryption code in main from Assignment $2$ needs to be placed

into two functions named encrypt and decrypt. Also, the the codebook, plaintext and ciphertext input

will be input as files instead of the command line. The only command line argument in A$03$ will be a

configuration file that contains the names of the input and output files, the shift amount $(-$k$),$ an option

to encrypt $(-$e$)$ or decrypt $(-$d$),$ and the codebook filename.

Refer to the code listing for details about all the functions to write. The encryption and decryption

algorithm $($shift cipher$)$ stays the same as described in the handout for assignment $2.$

For A$03,$ the sourcecode files defs.h with the configuration struct, A$03.$h file with function proto$-$

types, A$03.$cpp with the empty function definitions, an example autograder.cpp driver file, and the

codebook.csv have been provided in A$03.$zip. Read in the contents of the codebook.csv file and store

the values in a character array named codebook: char codebook$[64]$;$.$ Pass the codebook array to

your encrypt and decrypt functions. This approach differs from assignment $2$ when codebook was a

global variable.

Your A$03$ program will accept a single command line argument that is the name of the configuration

file. The contents of an example configuration file to encrypt are shown below:

$-$k $5$

$-$i plaintext.txt

$-$o ciphertext.txt

$-$e

$-$c codebook.csv

To decrypt, replace $-$e with $-$d and the input and output filenames in the configuration file.

Program Description and Functionality: Provide the following in your source file:

$1.$ Comments at the top of your $.$cpp file.

$2.$ Use the A$03.$cpp skeleton code file and implement all the defined functions

$3.$ Use only C$++$ headers that place all standard$-$library routines in namespace std$.$ For C$++$

file stream I$/$O use #include.

$4.$ The use of command line arguments $($int argc, char$*$ argv$[])$ will be used to get the configuration

filename and is hardcoded as argv$[1]$ in the example autograder.cpp application. Ensure your code

exits without an error if the filename argument is not provided.

$5.$ The characters for the codebook array are stored as a comma separated list in a file named

codebook.csv and are the same character$-$set used in A$02.$

$1)$Z $,$z $,$Y $,$y $,$X $,$x $,$W $,$w $,$V $,$v $,$U $,$u $,$T $,$t $,$S $,$s $,$R $,$r $,$Q $,$q $,\backslash$

$2)$P $,$p $,$O $,$o $,$N $,$n $,$M $,$m $,$L $,$l $,$K $,$k $,$J $,$j $,$I $,$i $,$H $,$h $,$G $,$g $,\backslash$

$3)$F $,$f $,$E $,$e $,$D $,$d $,$C $,$c $,$B $,$b $,$A $,$a $,9,8,7,6,5,4,3,2,\backslash$

$4)1,0,?,]$

$6.$ Implement the functions to assist with encrypting, decrypting and reading and writing the files for

assignment $3.$ Refer to the following code listing for the function specifications.

$1/*$ A$3$ : Write two functions encrypt and decrypt $.*/$

$2$ void encrypt $($ std :: string & plaintext $,$ int k $,$ char codebook $[],$ int codebook$\_$length $)$;

$3$ void decrypt $($ std :: string & ciphertext $,$ int k $,$ char codebook $[],$ int codebook$\_$length $)$;

$4$

$5/*$ A$3$ : Use the following struct to hold the current configuration $.$

$6$ provided in the defs $.$ h file $*/$

$7$

$8$ struct Configuration $\{$

$9$ int k $=0$;

$10$ std :: string config$\_$filename $=""$ ;

$11$ std :: string codebook$\_$filename $=""$ ;

$12$ std :: string infile $=""$ ;

$13$ std :: string outfile $=""$ ;

$14$ bool encrypt $=$ true ;

$15\}$;

$16$

$17/*$ A$3$ : Write a function to parse the configuration file and

$18$ initialize a configuration struct $.$

$19$

$20$ Tip : The configuration struct must be a reference or else no changes

$21$ will be preserved from the calling function $*/$

$22$

$23$ void par se$\_$config$\_$file $($ Configuration & c $)$

$24$

$25/*$ A$3$ : Write a function read$\_$codebook to read in the codebook $.$ csv file $.$

$26$

$27$ Tip : this function requires the configuration filename

$28$ read in from the command line arguments and stored in

$29$ the configuration Struct string member variable : c $.$ codebook$\_$filename $*/$

$30$

$31$ void read$\_$codebook $($ Configuration & c $,$ char codebook $[],$ int length $)$

$32$

$33/*$ A$3$ : Write a function to read the plaintext or ciphertext message from the infile

$34$

$35$ Tip : the Configuration struct c will contain the string c $.$ infile name

$36$ the msg is the same variable from A$02*/$

A$3$ Tasks : Implementation File A$0($I submitted SS top right is A$02$ encrypr decrypt code if u need it$.)$ Top left pic is what i need