Question

Write a program in python or c++ that has two functions:

Function one is called: _encrypt

Function Two is called: _decrypt

Function one takes plain text ,and assesses the indexed value of each letter in the string. For example, a=1,b=2 . It then adds three to the indexed valus , and produces encrypted text , based off of the plain text.

Function two reverse this.

here is sample output:

_encrypt(‘how do you do’)

Unsecured: howdoyoudo

Secured: lsahscsyhs

_decrypt(‘lsahscsyhs’)

Unsecured: lsahscsyhs

Secured: howdoyoudo

please attach your code and output . Test output as sample output

Answer 1

CODE;

#include <stdio.h>
#include <iostream>
using namespace std;

// returns the encrypted text
string encrypt(string text, int s)
{
   string result = "";

   // traverse text
   for (int i=0;i<text.length();i++)
   {
       // apply transformation to each character
       // Encrypt Uppercase letters
       if (isupper(text[i]))
           result += char(int(text[i]+s-65)%26 +65);

   // Encrypt Lowercase letters
   else
       result += char(int(text[i]+s-97)%26 +97);
   }

   // Return the resulting string
   return result;
}

// returns the decrypted text
string decrypt(string text, int s)
{
   string result = "";

   // traverse text
   for (int i=0;i<text.length();i++)
   {
       // apply transformation to each character
       // decryptEncrypt Uppercase letters
       if (isupper(text[i]))
           result += char(int(text[i]-s-65)%26 +65);

   // decrypt Lowercase letters
   else
       result += char(int(text[i]-s-97)%26 +97);
   }

   // Return the resulting string
   return result;
}

// Driver program to test the above function
int main()
{
   string text="IHATECHEGG";
   int s = 4;
   cout << "Encrypt : " << text;
   cout << "\nunsecured: " << text;
   cout << "\nsecured: " << encrypt(text, s);
   cout<<"\n";
   string ab=encrypt(text, s);
  
   cout << "decrypt : " << ab;
   cout << "\nunsecured: " <<ab;
   cout << "\nsecured: " << decrypt(ab,s);
   return 0;
}

output 2