encryption.cpp

C++大学简明教程,解压就行没有密码。希望对大家有用

// Exercise 19.12: Encryption.cpp
// Encrypts data entered by users.
#include <iostream> // required to perform C++ stream I/O
#include <string>   // required to access string functions

using namespace std; // for accessing C++ Standard Library members

// function prototypes
void substitutionCipher( string & );
void transpositionCipher( string & );

// function main begins program execution
int main ()
{
   // define variables
   string input; // stores the plain text that the user enters
   int selection; // stores a number corresponding to cipher type

   cout << "\nEnter plain text: ";
   getline( cin, input );

   cout << "\nSelect the encryption type" << endl;
   cout << "1 - Substitution cipher" << endl;
   cout << "2 - Transposition cipher" << endl;
   cout << "Enter selection: ";
   cin >> selection;

   // determine which encryption type to perform
   if ( selection == 1 )
   {
      substitutionCipher( input ); // call substitutionCipher
   } // end if
   else if ( selection == 2 )
   {
      transpositionCipher( input ); // call transpositionCipher
   } // end else if
   else
   {
      cout << "\nError: Please enter a valid menu option.\n" << endl;
   } // end else

   return 0; // indicate that program ended successfully

} // end function main

// using the substitution cipher, display encrypted text
void substitutionCipher( string &plainText )
{
   // normal alphabet string
   string normalAlphabet = "abcdefghijklmnopqrstuvwxyz .!?,";
   normalAlphabet += "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

   // substitution alphabet string
   string cipherAlphabet = "cdefg.hijk!lmn opqr?stuv,wxyzab";
   cipherAlphabet += "CDEFG.HIJK!LMN OPQR?STUV,WXYZAB";

   // define other local variables
   string cipher = ""; // encrypted string

} // end function substitutionCipher

// using the transposition cipher, display encrypted text
void transpositionCipher( string &plainText )
{
   // define local variables
   string firstWord = ""; // stores the first word
   string lastWord = "";  // stores the second word

} // end function transpositionCipher


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