Program: Hail Caesar! Caesar Cipher!


Simple Caesar Cipher for Raspberry Pi, Apple Mac or Linux PC.

Compile using GNU C++ compiler or paste into repl.it

Code below


// Caesar Cipher - Phil Gardner
#include <iostream>
using namespace std;
int main()
{
  cout<< "Hail Caesar!" << endl << endl;

  // Get person to type in their plain text
  string plain;
  cout << "Type in your message: ";
  getline(cin, plain);

  // Choose encryption key
  int key;
  cout << "Type in your key (1 to 25): ";
  cin >> key;

  cout << endl << "Encrypting..." << endl << endl;

  // Find length of message
  // this will tell us when to stop
  int len = plain.length();

  // Examine each character and change it
  // Starting from first character in message
  char currentChar;

  int position = 0;
  while ( position < len )
  {
     currentChar = plain[position];
     if ( isalpha( currentChar ) )
     {
        currentChar = toupper( currentChar );
        currentChar = currentChar + key;

        if ( currentChar > 'Z' )
            currentChar = currentChar - 26;
     }

     cout << currentChar;

     position++;
  }

   cout << endl;
}