private async Task <IndividualSet> CalcFitness(IndividualSet individualSet)
{
var substitution = new Substitution(Alphabet, individualSet.Select(i => i.Key).ToList());
string decryptedMessage = substitution.Decrypt(EncryptedText);
IEnumerable <double> results = await Task.WhenAll(
CalcFittingQuotient(decryptedMessage, _twoLettersFrequencies),
CalcFittingQuotient(decryptedMessage, _threeLettersFrequencies));
individualSet.Fitness = TwoLettersFittingQuotientCoef * results.ElementAt(0) +
ThreeLettersFittingQuotientCoef * results.ElementAt(1);
return(individualSet);
}
private IEnumerable <IndividualSet> GeneratePoputation(int size)
{
var random = new Random();
var population = new HashSet <IndividualSet>(size, new IndividualSetsComparer());
IndividualSet individualSet;
Individual individual;
while (population.Count != size)
{
individualSet = new IndividualSet(IndividualSetMembersCount);
while (individualSet.Count != IndividualSetMembersCount)
{
individual = new Individual(new string(Alphabet.ToCharArray().OrderBy(s => (random.Next(2) % 2) == 0).ToArray()), Alphabet.Length);
individualSet.Add(individual);
}
population.Add(individualSet);
}
return(population);
}
private List <IndividualSet> Crossover(IndividualSet firstSet, IndividualSet secondSet, bool needsMutation = false)
{
IndividualSet firstChildSet = new IndividualSet(IndividualSetMembersCount);
IndividualSet secondChildSet = new IndividualSet(IndividualSetMembersCount);
var random = new Random();
char[] firstChildKey, secondChildKey;
LinkedList <char> firstKeyCopy, secondKeyCopy;
List <(int index, int indicator)> positions;
for (int keyIndex = 0; keyIndex < firstSet.Count; keyIndex++)
{
firstChildKey = new char[Alphabet.Length];
secondChildKey = new char[Alphabet.Length];
firstKeyCopy = new LinkedList <char>(firstSet[keyIndex].Key);
secondKeyCopy = new LinkedList <char>(secondSet[keyIndex].Key);
positions = Enumerable.Range(0, Alphabet.Length)
.Select(i => (i, random.Next(0, 2))).ToList();
foreach ((int letterIndex, int indicator) in positions)
{
if (indicator == 0)
{
firstChildKey[letterIndex] = firstSet[keyIndex].Key[letterIndex];
secondKeyCopy.Remove(firstSet[keyIndex].Key[letterIndex]);
}
else
{
secondChildKey[letterIndex] = secondSet[keyIndex].Key[letterIndex];
firstKeyCopy.Remove(secondSet[keyIndex].Key[letterIndex]);
}
}
foreach ((int index, int indicator) in positions)
{
if (indicator == 1)
{
firstChildKey[index] = secondKeyCopy.First.Value;
secondKeyCopy.RemoveFirst();
}
else
{
secondChildKey[index] = firstKeyCopy.First.Value;
firstKeyCopy.RemoveFirst();
}
}
if (needsMutation)
{
int randomPos = random.Next(0, Alphabet.Length);
int firstLetterIndex = random.Next(0, randomPos);
int secondLetterIndex = random.Next(randomPos, Alphabet.Length);
Swap(firstChildKey, firstLetterIndex, secondLetterIndex);
Swap(secondChildKey, firstLetterIndex, secondLetterIndex);
}
firstChildSet.Add(new Individual(new string(firstChildKey), Alphabet.Length));
secondChildSet.Add(new Individual(new string(secondChildKey), Alphabet.Length));
}
return(new List <IndividualSet> {
firstChildSet, secondChildSet
});
void Swap(char[] childKey, int firstLetterIndex, int secondLetterIndex)
{
char temp = childKey[firstLetterIndex];
childKey[firstLetterIndex] = childKey[secondLetterIndex];
childKey[secondLetterIndex] = temp;
}
}
