How to change elements from string to string for Caesar Cipher

Question

I need to assign the user-entered string from the alphabet I created

using namespace std;

int main() {
  setlocale(LC_ALL, "Turkish");
  string str1;
  string alphabet[29] = {"a", "b", "c", "ç", "d", "e", "f", "g", "ğ", "h",
                         "ı", "i", "j", "k", "l", "m", "n", "o", "ö", "p",
                         "r", "s", "ş", "t", "u", "ü", "v", "y", "z"};

  cout << "Enter sentence";
  getline(cin, str1);

  for (int i = 0; i < str1.length(); i++) {
    for (int j = 0; j < 29; j++) {
      if (alphabet[j].compare(string(1, str1.at(i))))

      {
        j = (j + 3) % 29;

        str1.assign(alphabet);
        break;

      }  // if
    }    // for(j)

  }  // for(i)

  cout << "Encrypted message is:-->" << str1 << endl;

  return 0;
}

each letter in the entered string must be 3 steps. but this code does not work.

Answer 1

Assign is not the right function.

You need another variable, we can say std::string str2;

Instead of str1.assign(alphabet) try use str2.append(alphabet[j]).

At the end of the cycle you will have in the str2 your string encrypted.

Try this code:

int main() {
  setlocale(LC_ALL, "Turkish");
  string str1;
  string str2;
  string alphabet[29] = {"a", "b", "c", "ç", "d", "e", "f", "g", "ğ", "h",
                         "ı", "i", "j", "k", "l", "m", "n", "o", "ö", "p",
                         "r", "s", "ş", "t", "u", "ü", "v", "y", "z"};

  cout << "Enter sentence";
  getline(cin, str1);

  for (int i = 0; i < str1.length(); i++) {
    for (int j = 0; j < 29; j++) {
      if (alphabet[j] == str1.substr(i,1))

      {
        j = (j + 3) % 29;

        str2.append(alphabet[j]);
        break;

      }  // if
    }    // for(j)

  }  // for(i)

  cout << "Encrypted message is:-->" << str2 << endl;

  return 0;
}