School-Coding-Cpp/sfusi/encrypt_affineCipher.cpp

46 lines
817 B
C++

/*
Nome: Mario
Cognome: Montanari
Classe: 3AIN
Data: 08/03/2025
*/
#include <iostream>
#include <cctype>
#define SIZE 100+1
using namespace std;
char *encryptAffineCipher(char *const str, const int a, const int b);
int main(void) {
char str[SIZE];
int a;
int b;
cout << "Inserisci una frase: ";
cin.getline(str, SIZE);
cout << "a: ";
cin >> a;
cout << "b: ";
cin >> b;
cout << "Frase codificata: " << encryptAffineCipher(str, a, b) << endl;
return 0;
}
char *encryptAffineCipher(char *const str, const int a, const int b) {
for (int i = 0; str[i] != '\0'; i++) {
if (isupper(str[i])) {
str[i] = (a * (str[i] - 'A') + b) % 26 + 'A';
} else if (islower(str[i])) {
str[i] = (a * (str[i] - 'a') + b) % 26 + 'a';
}
}
return str;
}