Question

Q: IN C++ -  Redesign the CaesarCipher class as a subclass of the SubstitutionCipher from the previous problem

my code is:

#include <iostream>
#include <string>

using namespace std;

class SubstitutionCipher {
public:
//Define your key which is a permutation of 26 alphabets
string key;

//Constructor to create an instance which initializes the key with the given permutation
SubstitutionCipher(string k) {
key = k;
}

//function to encode a string
string encode(string data) {
//initialize encoded data
string encodedData = data;
//replace each character in encodedData with the corresponding mapped data in key. We subtract a char with 'A' to get its position
for (int i = 0; i < data.length(); i++) {
encodedData[i] = key.at(data.at(i) - 'A');
}
//return the encoded data
return encodedData;
}

//function to decode a string
string decode(string data) {
//initialize decoded data
string decodedData = data;
//replace each character in decodedData with the corresponding reverse mapped data in key. We add the position with 'A' to get the corresponding char
for (int i = 0; i < data.length(); i++) {
decodedData[i] = key.find(data.at(i)) + 'A';
}
//return the decoded data
return decodedData;
}

};

//main() method to test the implementation
int main() {
SubstitutionCipher cipher("ZYXWVUTSRQPONMLKJIHGFEDCBA");
string data = "DEBAJYOTI";
string encodedData = cipher.encode(data);
cout << data << " encoded as " << encodedData << endl;
string decodedData = cipher.decode(encodedData);
cout << encodedData << " decoded as " << decodedData;
}

Answer 1

#include <iostream>
#include <string>

using namespace std;

class SubstitutionCipher {
public:
//Define your key which is a permutation of 26 alphabets
string key;

//Constructor to create an instance which initializes the key with the given permutation
SubstitutionCipher(string k) {
key = k;
}

//function to encode a string
string encode(string data) {
//initialize encoded data
string encodedData = data;
//replace each character in encodedData with the corresponding mapped data in key. We subtract a char with 'A' to get its position
for (int i = 0; i < data.length(); i++) {
encodedData[i] = key.at(data.at(i) - 'A');
}
//return the encoded data
return encodedData;
}

//function to decode a string
string decode(string data) {
//initialize decoded data
string decodedData = data;
//replace each character in decodedData with the corresponding reverse mapped data in key. We add the position with 'A' to get the corresponding char
for (int i = 0; i < data.length(); i++) {
decodedData[i] = key.find(data.at(i)) + 'A';
}
//return the decoded data
return decodedData;
}

};
class ccipher: public SubstitutionCipher
{
   public:
void encrypt(string text, int s)
{
   string result = "";

   // traverse text
   for (int i=0;i<text.length();i++)
   {
       // apply transformation to each character
       // Encrypt Uppercase letters
       if (isupper(text[i]))
           result += char(int(text[i]+s-65)%26 +65);

   // Encrypt Lowercase letters
   else
       result += char(int(text[i]+s-97)%26 +97);
   }

   // Return the resulting string
//   return result;
cout << "\n C_Cipher: " <<result;
}   
};

//main() method to test the implementation
int main() {
SubstitutionCipher cipher("ZYXWVUTSRQPONMLKJIHGFEDCBA");
string data = "DEBAJYOTI";
string encodedData = cipher.encode(data);

cout << data << " encoded as " << encodedData << endl;
string decodedData = cipher.decode(encodedData);
cout << encodedData << " decoded as " << decodedData;
ccipher cc;
cc.encrypt(data, 4);
}