Re: encryption problem
"Wilson" wrote:
i am learning to program using c++ and was set a task of making a
simple encryption algorithim. I choose to start with one where simply
each letter is replaced with its equivilent in the alphabet when
written backmards, i am hoping to make this more complex soon. Below
is the program i wrote but it does not work, it simply returns the
exact same text you enter. Could you please advise on how to sort
this, and also suggest any ways of generating random letters, for
future refernce.
It didn't do what you say it does for me. If I type mary I get back ZYXW.
The first four letters in the backwards alphabet you provided as a literal.
That's what the code said it should do. The code says: replace the first
letter with Z, the next letter with Y and so on. You don't even examine
the *value* of the character read. Think about it and try again. The
random letter issue is covered in the FAQ for comp.lang.c
I don't think it is a good idea to write an enciphered message, even if done
properly, in a variable named plain_text. It is confusing. If you only
have a few hundred bytes of memory, name it buffer. If you can cram it in,
create a new variable named cipher_text and put the enciphered text there.
Also, cut and paste next time, what you posted does not compile.
#include <iostream>
#include <string>
using namespace std;
char alphabet[27] = "ZYXWVUTSRQPONMLKJIHGFEDCBA";
char plain_text[27];
int string_length;
int main()
{
cout << "text: ";
cin >> plain_text;
string_length = strlen(plain_text);
for(int i=0; i < string_length; i++)
{
plaintext[i] = alphabet[i];
}
cout << plain_text;
system ("PAUSE");