Hi, encryption program

[Blue_turnip]

Hi im relatively new to programming and I am working on an encryption program. I know what I want to do but im a bit lost, youll understand when you see my code.

This is just the start of my code by the way

#include <iostream>
using namespace std;

int main()

{

    char unencrypted;
    char encrypted;

    cout <<  "Enter unencrypted English:"
            << endl;
    cin >> unencrypted;

Basically, there will be no algorithm. I want to state like a= f, b = z, c =q and I want each letter in the code the user has submitted to be translated. Any advice would be greatly appreciated.

[Salem]

So basically you want to map between two character sets

char clear[] = "abc";
char cypher[] = "fzq";

Find the position of a letter in the clear array, and use that position to index the cypher array

[Blue_turnip]

sorry i dont understand what you posted just then. Sorry but could you clarify

thanks alot

[Salem]

Use a for loop

As in
for ( i = 0 ; i < n ; i++ ) if ( clear[i] == unencrypted )
etc etc

[Blue_turnip]

Sorry, i didnt get that either.

[MadCow257]

you can use a switch statement, that would make it real easy

[Salem]

Last chance

for ( i = 0 ; i < n ; i++ ) if ( clear[i] == unencrypted ) encrypted = cypher[i];

[Da-Nuka]

Something like this

#include  <iostream>
#include  <string>
using namespace std;
char Translate(char);




int main() {
int i;
int length;
string unencrypted;
string encrypted;

cout <<"Enter unencryped english:" <<endl;
cin >> unencrypted;
length=unencrypted.length();



for(i=0; i < length; i++) {
unencrypted[i]=Translate(unencrypted[i]); 
}




cout <<unencrypted;
return 0;
}






char Translate(char a) {
if(a == 'a') return 'a';
if(a == 'b') return 'c';
if(a == 'c') return '2';
else return '.'; // default
//and so on.....//
}

you understood?

edit: Code tags added by Govtcheez - USE CODE TAGS, JERKS!
edit2: Wait, there was no indentation to begin with...

[Shakti]

Now if you only could use code tags.

[MadCow257]

and instead of

char Translate(char a) {
if(a == 'a') return 'a';
if(a == 'b') return 'c';
if(a == 'c') return '2';
else return '.'; // default
//and so on.....//

use a switch statement because it's faster then checking all the ifs

char Translate(char a) {
switch (a)
{
     case 'a':
          return 'a';
          break;
     case 'b';
          return 'c';
          break;
     case 'c';
          return '2';
          break;
     // and so on
}

[hk_mp5kpdw]

int length;

length = unencrypted.length();

To be correct, length should be described as string::size_type and not an int.

string unencrypted;

for(i=0; i < length; i++) {
unencrypted[ i ]=Translate(unencrypted[ i ]); 
}

cout <<unencrypted;

I think you meant encrypted instead of unencrypted above. Also, be careful, because unless you've allocated space for the string you are playing with fire. Easiest way to deal with that might be:

for(i=0; i < length; i++)
{
    encrypted += Translate(unencrypted[ i ]); 
}

Personally I'd use a map<char,char> to store the unencrypted(key)/encrypted(value) pairs but that might be a bit advanced for a beginner.

[Loctan]

I am new to C++ programming and thought I would give this a try. I
think this is what you were wanting to do. All you have to do is change what maps to what.

#include <iostream>
#include <string>

using namespace std;
string text, encText;
char translate(char a)
{
     switch(a)
     {
               case 'a':
                    return 'b';
               case 'b':
                    return 'c';                    
               case 'c':
                    return 'd';
               case 'd':
                    return 'e';
               case 'e':
                    return 'f';                    
               case 'f':
                    return 'g'; 
               case 'g':
                    return 'h';
               case 'h':
                    return 'i';                    
               case 'i':
                    return 'j';
               case 'j':
                    return 'k';
               case 'k':
                    return 'l';                    
               case 'l':
                    return 'm'; 
               case 'm':
                    return 'n';
               case 'n':
                    return 'o';                    
               case 'o':
                    return 'p';
               case 'p':
                    return 'q';
               case 'q':
                    return 'r';                    
               case 'r':
                    return 's'; 
               case 's':
                    return 't';
               case 't':
                    return 'u';                    
               case 'u':
                    return 'v';
               case 'v':
                    return 'w';
               case 'w':
                    return 'x';                    
               case 'x':
                    return 'y';  
               case 'y':
                    return 'z';                    
               case 'z':
                    return 'a';                                                                                                   
               default:
                    return ' ';     
     }
}
int main()
{
    cout << "Enter the string to be encripted:\n";
    cin >> text;

    for (int i = 0; i < text.size(); i++)
    {
        encText += translate(text[i]);
    }
    cout << encText << endl;
    cin >> encText;
}

[gcn_zelda]

In theory, that would work, but it's a bit lengthy. If you wanted efficiency, merely add one to each character in the word, as you can see in my(more like Thantos' fix of) program, that would cut off a heck of a lot of program sizeness in the other. It's in the Encryption Algorithm thread.

[Loctan]

Thanks for the tip. I didn't know that you could treat the characters as integers and just add one. For anyone who doesn't understand, essentially my entire translate function could be changed to:

char translate(char a)
{
     return (a + 1);
}

[sean]

Don't forget to add a conditional before your return statement: z doesn't fit in with the rest of the alphabet in this case. I hope you keep going with this project and add some features like handling upper AND lower case.

edit: Most of the upper case alphabet will also be handled by adding one, but I meant to account for z and Z.