Please help me to rewrite following code in different way: #include

#include

#include

using namespace std;

string encrypt$($string$,$ string$)$;

string decrypt$($string$,$ string$)$;

void encryptFile$($string$,$ string, string$)$;

void decryptFile$($string$,$ string, string$)$;

int main$()\{$

int s;

string inputFile, outputFile, key;

cout $<<$ "Encrypt a file$(1)/$Decrypt a file$(2)"<<$ endl;

cout $<<$ "Enter your selection: $"$;

cin $>>$ s;

while $($s $!=1$ && s $!=2)\{$

cout $<<$ "Invalid selection. Please enter $1$ to encrypt or $2$ to decrypt: $"$;

cin $>>$ s;

$\}$

cout $<<$ "Enter name for input file: $"$;

cin $>>$ inputFile;

cout $<<$ "Enter name for output file: $"$;

cin $>>$ outputFile;

$//$ Any word is fine but no numbers only intergers and it has to be same for encypt and decrypt

cout $<<$ "Enter a string key to execute it: $"$;

cin $>>$ key;

if $($s $==1)\{$

encryptFile$($inputFile$,$ outputFile, key$)$;

cout $<<$ "Encrypted" $<<$ endl;

$\}$ else if $($s $==2)\{$

decryptFile$($inputFile$,$ outputFile, key$)$;

cout $<<$ "Decrypted" $<<$ endl;

$\}$

return $0$;

$\}$

$//$ Vigen$$re cipher encryption function

string encrypt$($string plaintext, string key$)\{$

string encryptedText $=""$;

int keyIndex $=0$;

int keyLength $=$ key.length$()$;

$//$ Loop through each character in the plaintext

for $($char &c : plaintext$)\{$

if $($isalpha$($c$))\{//$ Encrypt only alphabetic characters

char base $=$ islower$($c$)?\text{'}$a$\text{'}$ : $\text{'}$A$\text{'}$; $//$ Determine case $($lower or upper$)$

int shift $=$ tolower$($key$[$keyIndex $\%$ keyLength$])-\text{'}$a$\text{'}$; $//$ Get the shift amount

encryptedText $+=($c $-$ base $+$ shift$)\%26+$ base; $//$ Apply the shift

keyIndex$++$; $//$ Only increment keyIndex for alphabetic characters

$\}$ else $\{$

$//$ Non$-$alphabetic characters are added as$-$is

encryptedText $+=$ c;

$\}$

$\}$

return encryptedText;

$\}$

$//$ Vigen$$re cipher decryption function

string decrypt$($string ciphertext, string key$)\{$

string decryptedText $=""$;

int keyIndex $=0$;

int keyLength $=$ key.length$()$;

$//$ Loop through each character in the ciphertext

for $($char &c : ciphertext$)\{$

if $($isalpha$($c$))\{//$ Decrypt only alphabetic characters

char base $=$ islower$($c$)?\text{'}$a$\text{'}$ : $\text{'}$A$\text{'}$; $//$ Determine case $($lower or upper$)$

int shift $=$ tolower$($key$[$keyIndex $\%$ keyLength$])-\text{'}$a$\text{'}$; $//$ Get the shift amount

decryptedText $+=($c $-$ base $-$ shift $+26)\%26+$ base; $//$ Apply the reverse shift

keyIndex$++$; $//$ Only increment keyIndex for alphabetic characters

$\}$ else $\{$

$//$ Non$-$alphabetic characters are added as$-$is

decryptedText $+=$ c;

$\}$

$\}$

return decryptedText;

$\}$

$//$ Encrypt the file using Vigen$$re cipher

void encryptFile$($string inputFileName, string outputFileName, string key$)\{$

ifstream fin$($inputFileName$)$;

ofstream fout$($outputFileName$)$;

string line;

if $(!$fin.is$\_$open$())\{$

cout $<<$ "Error: Unable to open input file!" $<<$ endl;

return;

$\}$

if $(!$fout.is$\_$open$())\{$

cout $<<$ "Error: Unable to open output file!" $<<$ endl;

return;

$\}$

$//$ Encrypt each line and write it to the output file

while $($getline$($fin$,$ line$))\{$

fout $<<$ encrypt$($line$,$ key$)<<$ endl;

$\}$

fin.close$()$;

fout.close$()$;

$\}$

$//$ Decrypt the file using Vigen$$re cipher

void decryptFile$($string inputFileName, string outputFileName, string key$)\{$

ifstream fin$($inputFileName$)$;

ofstream fout$($outputFileName$)$;

string line;

if $(!$fin.is$\_$open$())\{$

cout $<<$ "Error: Unable to open input file!" $<<$ endl;

return;

$\}$

if $(!$fout.is$\_$open$())\{$

cout $<<$ "Error: Unable to open output file!" $<<$ endl;

return;

$\}$

$//$ Decrypt each line and write it to the output file

while $($getline$($fin$,$ line$))\{$

fout $<<$ decrypt$($line$,$ key$)<<$ endl;

$\}$

fin.close$()$;

fout.close$()$;

$\}$