public override string Criptoanaliza(string s)
{
litere L1 = new litere('Z' - 'A' + 1); // aparitia literelor intr-un text oarecare
litere L2 = new litere('Z' - 'A' + 1); // aparitia literelor in textul criptat
EnumerareLitere(ref L1, @"Random_text.txt");
EnumerareLitere(ref L2, @"text_criptat.txt");
SortareDesc(ref L1);
SortareDesc(ref L2);
StringBuilder sb = new StringBuilder();
int j;
for (int i = 0; i < s.Length; i++)
{
if ('A' <= s[i] && s[i] <= 'Z')
{
// cautam litera potrivita in lista de aparitie
for (j = 0; s[i] != L2.caracter[j]; j++)
{
;
}
// adaugam litera corespunzatoara
sb.Append(L1.caracter[j]);
}
else
{
sb.Append(s[i]);
}
}
return(sb.ToString());
}
private void SortareDesc(ref litere L)
{
bool ok = false;
int n = L.caracter.Length;
do
{
ok = true;
for (int i = 0; i < n - 1; i++)
{
if (L.aparitie[i] < L.aparitie[i + 1])
{
ok = false;
Schimba <float>(ref L.aparitie[i], ref L.aparitie[i + 1]);
Schimba <char>(ref L.caracter[i], ref L.caracter[i + 1]);
}
}
} while (!ok);
}
private void EnumerareLitere(ref litere L, string file)
{
L = new litere('Z' - 'A' + 1);
StreamReader sr = new StreamReader(file);
char c; int i;
do
{
c = Convert.ToChar(sr.Read());
c = char.ToUpper(c);
if ('A' <= c && c <= 'Z')
{
i = 0;
while (c != L.caracter[i])
{
i++;
}
L.aparitie[i]++;
}
} while (!sr.EndOfStream);
}
