Thread: Unknown problem in first encryption algorythm

Hi all. I just recently found an old encryption program I gave up on back in highschool on an old jump drive. I was wanting to teach myself about typecasting, file I/O, and a little encryption all in the same project. I actually wrote two programs. The first takes in a phrase one letter at a time and converts them to numbers through typecasting. Next, It adds whatever number is in the file "numerical.txt" and writes the resulting number to a file called "example.txt". Whenever it comes time to undo what has been done, the second program simply reverses the process by reading from the two files and subtracting. Problem is, instead of perfectly legible letters, I simply get the symbol for null (I believe that's what it is). When I open up example.txt, the numbers are huge. (In the hundreds of thousands, instead of the standard ascii), so I'm assuming the problem is in the encryption algorithm. I'd love to finally be able to get this program to work. Anyway, here's the code:


Encryptor:

Code:

#include <fstream>
#include <iostream>
#include <cstdlib>
#include <stdio.h>
#include <windows.h>
#include <process.h>
using namespace std;




int main()
{
    cout<<"Personal encryptor, v 0.2\n";
    cout<<"Andrew Hodge. June 10, 2011. \n \n \n" << endl;

int str;
int alexandria;
char input;
int oxnhill;
int laurel;
oxnhill = 1;
washington:

ifstream c_file("numerical.txt");
c_file>>laurel;
c_file.close();


while (oxnhill< 0){

ofstream a_file ("example.txt", ios::app);
a_file<<  "Unit line______Score_________\n";
a_file.close();

//oxnhill++;

goto washington;

}
    cin>>input;
    if (input==99){

    goto arnold_sw;

    }
    else{
  alexandria=(int)input ;

  ofstream a_file ( "example.txt", ios::app );
a_file<<alexandria + laurel;
a_file<<"\n"
  a_file.close();
    goto washington;
    }

    arnold_sw:

    return 0;

}

Decryptor:

Code:

#include <fstream>
#include <iostream>
#include <cstdlib>
#include <stdio.h>
#include <windows.h>
#include <process.h>
using namespace std;

int main(){

    int alexandria;
    int laurel;
    int baltimore;
    int patomic;
    ifstream a_file ("numerical.txt");
    a_file>>laurel;
    a_file.close();

    ifstream b_file ("example.txt");
    b_file>>alexandria;
    b_file.close();
    baltimore= alexandria-laurel ;

   patomic= baltimore;
   cout<< (char) patomic ;



}

Ha. No. I'm currently using 15.


and I'm also working on a string like "end" instead of c.

Wow, just... wow!
Turning ifs into loops, and turning loops into gotos...
I'm not even sure what manner of unholyness is going to occur due to using a goto to jump back before the definition of some local variables that are not POD types. I'm not sure I even want to know.

Every time you use a goto, someone kills a kitten. Please make it stop!

The most obviously thing lacking now is good formatting, e.g.,

Code:

#include <iostream>
#include <fstream>

using namespace std;

int main() {
    char washington;
    int alexandria;
    int arlington;
    int oxonhill;
    int silverspring;
    int bolling;
    int laurel;

    cout << "P_encrypt\n";
    cout << "Enter encryptor";
    cin >> alexandria;// My "encryptor". Instead of file input, I decided to do something a bit more "on my level"
    cout << "Encryptor has been set to "<<alexandria<<endl;
    cout << "Enter data to encrypt, one letter at a time. Enter letter [q] to goto decryptor." << endl;//No, that is not a goto statement.
    do {
        cin >> washington;
        arlington = (int)washington + alexandria;
        ofstream one("store.txt", ios::app);
        one << arlington << "\n";
        one.close();
        cin.get();
    }
    while (washington != 113);// Until I figure out how to typecast an entire string (like "quit") into an int,
    // "q" will have to do.

    //Program automatically goes to this when encryption loop ends, rigt?

    cout << "Entering decryption mode. Please enter decryptor";
    cout << " (same as encryptor when file was written to.)";
    cin >> oxonhill;
    ifstream two("store.txt");
    if (two.is_open())
    do {
        two >> laurel;
        laurel - oxonhill;
        cout << (char)laurel;
        cin >> bolling;
    }
    while (bolling != 100);
}

Next, what's with those variable names? You should use variable names that are descriptive.

They're better than single character variables, but not by much. You should name variables after the information they store.