Ceaser Cipher Decryption

[thomas1234]

Hello, my purpose is converting bcç to abc (1 time shifting with decryption) you can wonder what is "ç".
"ç"is one of the Turkish alphabet letter and I would like to conver letter "b" to a, letter "c" to "b"and letter "ç" to "c" can you help me for this code. Thanks.

[MiiNiPaa]

It depends on order of characters in your local codepage. Try to do:

char n = 'c';//Turkish c, not english.
++n;
std::cout << n;

if it gives you a 'ç', everything is fine. If not, you will have to go the hard way.

[thomas1234]

Output is "d" not "ç" :(

A friend said " I would recommend you to use a substitution table. Create an array of 256 characters (one for each code-point in your character encoding table) and fill each code-point with the letter which is supposed to be used instead of it. Then iterate the input text and replace each character by looking it up in that array."

but I didnt understand what he means :(

[MiiNiPaa]

For example with digits:

#include <iostream>

int main ()
{
    char original[10] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
    char substitute[10] = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0'};
    char line[] = "123";
    int index = 0;
    while(line[index])
    {
        int i = -1;
        while(line[index] != original[++i]) //finds index of character in original array
            ;
        line[index++] = substitute[i]; //Replaces it with corresponding character from substitute array
    }
    std::cout << line;
}

[thomas1234]

Thank u so much I understand now.