public IEnumerable <char> Decode(string stringToDecode)
{
if (stringToDecode.Any(n => !Alphabet.Contains(n) && !Separators.Contains(n)))
{
throw new Exception("Finded symbol not from alphabet");
}
string s = string.Empty;
for (int i = 0; i < stringToDecode.Length; i++)
{
if (Separators.Any(n => n == stringToDecode[i]))
{
s += stringToDecode[i];
}
else
{
s += Alphabet[LookupTable[i % KeyWord.Length].IndexOf(stringToDecode[i])];
}
}
return(s);
}
//Encrypts the message using the key
public static string Encrypt(string message, string key)
{
message = message.ToUpper();
key = key.ToUpper();
string plaintext = "";
int i = 0;
foreach (char element in message)
{
if (!Char.IsLetter(element))
{
plaintext += "";
}
else
{
int MOrder = Alphabet.EnglishAlphabet().FirstOrDefault(x => x.Value == element).Key;
int KOrder = Alphabet.EnglishAlphabet().FirstOrDefault(x => x.Value == key[i]).Key;
int Final = (int)(MOrder - KOrder);
if (Final < 0)
{
Final += 26;
}
plaintext += Alphabet.EnglishAlphabet()[Final];
i++;
}
if (i == key.Length)
{
i = 0;
}
}
return(plaintext);
}
