Simple Encryption Program

[unfeomateo]

I need to encrypt a paragraph out of a txt file.

I can get the info from the txt file into a vector with no problem.

But then I need to encrypt the data using this key "wyijkcuvdpqlzhtgabmxefonrs"

Where each letter represents a letter in the alphabet.

w = a
y = b
i = c and so on.

My problem is I have never done anything like this before and have no idea where to start or how this will work.

Any help is appreciated!!!!

Thank you



Eclipse / WinXP

[GuOddian]

Hi!

You could approach this problem many ways, I think the most simple is to create a hash map of associations matching each letter with its corresponding replacement. I.E. "a"="w", "b"=y" and so on and so forth. Using this you could load each letter from your file you're trying to encrypt and just look up its replacement before writing it back to the encrypted file.

If you need help with hash maps I would suggest here: http://www.cprogramming.com/tutorial/stl/stlmap.html

[wilan]

A simpler solution is to store the encryption into a character array or string.
i.e. string mappings = "wyijkcuvdpqlzhtgabmxefonrs";
Then when you loop through your text simply concatenate the i-th character of mappings like:

for (int i = 0; i < vec.size(); i++) {
   for (int j = 0; j < vec[i].size(); j++) {
       cout << mappings[vec[i][j]-'a'];
   }
   cout << "\n";
}

This just prints to stdout but it's easy to modify depending on your requirements.
EDIT: Seems like I had the reversed direction of the mappings, but you can just assign the mappings string in reverse and it should do the same job.

[nerdykid]

here's a little bit of code i was writing for pleasure. it doesnt use a vector, but it works perfectly fine.

void encryptor(string filename)
{
  filename += ".txt";

  string ofilename, line;
  ofilename = "o" + filename;

  ifstream file (filename.c_str());
  ofstream ofile (ofilename.c_str());  

  if (file.is_open() && ofile.is_open())
  {
    while (!file.eof())
    {
      getline (file, line);
      ofile << encryptKey(line) << '\n';
    }
  file.close();
  ofile.close();
  }
  else
  {
    cout << "Unable to open one of the files";
  }
}

but i couldnt get it to overwirte the original text file, so it outputs it to the filename plu 'o'. also, the parameter filename is inputted in the main function using getline, and encryptkey is just a switch statement with the encryption key.