caesar sallad

gistfile1.txt

#include <iostream>
#include <string>
#include <limits>



int INPUT_MESSAGE = 1;
int ENCRYPT = 2;
int DECRYPT = 3;
int ANALYZE = 4;
int QUIT = 0;

using namespace std;

int& displayMenu(){

	int* option = new int();

		cout << "MAIN MENU" << endl << endl;
		cout << "1. To input a message" << endl;
		cout << "2. To encrypt a message " << endl;
		cout << "3. To decrypt a message" << endl;
		cout << "4. to perform a statisical analysis of the message" << endl;
		cout << "Press 0 to quit" << endl <<endl;
		cout << "Please choose:";
		cin >> *option;

	return *option;
}
void analyze(char *message){
	int letterFrequency[26] ={0};
	for( int i=0; i < ((string)message).length(); i++){
		
		letterFrequency[tolower(message[i]) - 97]++;
	}
	for( int i=0; i < sizeof(letterFrequency)/4; i++){
			
		cout << (char)(i + 97) << ": " << letterFrequency[i] << endl; 
	}

	float vowelCount = 0;
	float constCount = 0;

	for(int i = 0; i < sizeof(letterFrequency)/4; i++){
	
		if( i == (int) 'a' - 97 || i == (int) 'e' - 97 || i == (int) 'i' - 97 || i == (int) 'o' - 97 || i == (int) 'u' - 97){
		
			vowelCount += letterFrequency[i];
		}
		else{

			constCount += letterFrequency[i];
		}

	}

	float vc = vowelCount/constCount;

	if( constCount == 0){
	
		cout << numeric_limits<float>::has_infinity << endl;
	}
	else{

		cout << "The V/C count is: " << vc << endl;
	}
}

char* caesarShift(char *message, int shift, char *encryptedMessage){

	for( int i=0; i < ((string)message).length(); i++){

		if( islower(message[i])){
			
			encryptedMessage[i] = (((int)message[i] - 97) + shift)%26 + 97;
            if(encryptedMessage[i] < 97){
                encryptedMessage[i] += 26;
            } 
		}
		else if(isupper(message[i])){

			encryptedMessage[i] = (((int)message[i] - 65) + shift)%26 + 65;
            if(encryptedMessage[i] < 65){
                encryptedMessage[i] += 26;
            } 
		}
	
	}

	encryptedMessage[((string)message).length()] = NULL;

	return message;
}

int main(){

	char message[141];
	char encryptedMessage[141];
	int option=1;
	int shift;
	bool messageGiven = false;
	char Answer;
	char newMessage;

	cout << "COP 2271 Encrypter/Decrypter" << endl;
	cout << "This program is suppose to encrypt and decrypt messages using the Caesar Cipher algorithm." << endl << endl;

	while(option != QUIT){
		
		option = displayMenu();

		if(option == INPUT_MESSAGE){
			if(messageGiven == true){
				
				cout << "Are you sure you want to modify the input? (y/n)";
				cin >> Answer;
				if(Answer == 'n'){
					cout << "Returning to the main menu..\n\n"; }

				else if(Answer == 'y'){

					cout << "Please give new text: " << endl;
                    cin.get();
					cin.getline(message,141);
			
				}
			}
            else{

            cout << "Please give message:";
            cin.get();
            cin.getline(message,sizeof(message));
            messageGiven = true;
			
            }
        }

		else if(option == ENCRYPT){

			cin.get();
			cout << "Please give the number of shifts to the left:";
			cin >> shift;

			caesarShift(message, -shift, encryptedMessage);

			cout << "The encrypted message will be:"<< encryptedMessage << endl;
		}

		else if(option == DECRYPT){

			cin.get();
			cout << "Please give the number of shifts to the right:";
			cin >> shift;

			caesarShift(message, shift, encryptedMessage);

			cout << "The decrypted message is:"<< encryptedMessage << endl << endl;
		}

		else if(option == ANALYZE){
			cin.get();
			analyze(message);

		
		}

		else if(option == QUIT){
			cout << "Now quitting..."<<endl;
			break;
		}

		else
			cout << "Wrong choice, please choose again."<< endl <<endl;

	}



return 0;
}