private string SolveCoveringProblem()
{
List <string> trueReduced = True.ToList();
SortedList <string, int> implicantsCovering = new SortedList <string, int>();
List <string> resultCovering = new List <string>();
List <string> answer = new List <string>();
foreach (var str in ExpansionBuffer)
{
implicantsCovering.Add(str, CoveringTerms(str));
}
do
{
int maximum = implicantsCovering.Max((z) => { return(z.Value); });
for (int j = 0; j < implicantsCovering.Count; j++)
{
if (implicantsCovering.ElementAt(j).Value == maximum)
{
AddResult(implicantsCovering.ElementAt(j).Key);
ReduceTrue(trueReduced, implicantsCovering.ElementAt(j).Key);
answer.Add(implicantsCovering.ElementAt(j).Key);
implicantsCovering.RemoveAt(j--);
UpdateValues();
}
}
if (implicantsCovering.Count == 0 && trueReduced.Count != 0)
{
return("Недостаточно импликант было сгенерировано.");
}
} while (trueReduced.Count > 0);
StringBuilder result = new StringBuilder("");
StringBuilder buf = new StringBuilder(new string(Enumerable.Repeat('-', Length).ToArray()));
for (int i = 0; i < answer.Count; i++)
{
for (int k = 0; k < Length; k++)
{
if (buf[k] == '-')
{
if (answer[i][k] != '-')
{
buf[k] = '1';
}
}
}
}
int variables = 0;
for (int k = 0; k < Length; k++)
{
if (buf[k] != '-')
{
variables++;
}
}
mainForm.Invoke((Action) delegate { mainForm.UpdateVC(variables, answer.Count); });
for (int k = 0; k < resultCovering.Count - 1; k++)
{
result.Append(resultCovering[k]);
result.Append('+');
}
result.Append(resultCovering.Last());
return(result.ToString());
void UpdateValues()
{
for (int i = 0; i < implicantsCovering.Count; i++)
{
implicantsCovering[implicantsCovering.ElementAt(i).Key] = CoveringTerms(implicantsCovering.ElementAt(i).Key);
}
}
int CoveringTerms(string implicant)
{
int count = 0;
for (int i = 0; i < trueReduced.Count; i++)
{
for (int k = 0; k < Length; k++)
{
if (implicant[k] == '-' && k != Length - 1)
{
continue;
}
if (implicant[k] != trueReduced[i][k] && implicant[k] != '-')
{
break;
}
if (k == Length - 1)
{
count++;
}
}
}
return(count);
}
void AddResult(string implicant)
{
StringBuilder sb = new StringBuilder("");
for (int i = 0; i < Length; i++)
{
if (implicant[i] != '-')
{
if (implicant[i] == '0')
{
sb.Append('!');
}
sb.Append('X');
sb.Append(i);
}
}
resultCovering.Add(sb.ToString());
}
}
private void CD_Search()
{
long iteration = 0, ellapsedIterations = 0, lastChangeIteration = 0, implicantsCount = 0;
DateTime startTime = DateTime.Now;
while (true)
{
if (ellapsedIterations == long.MaxValue || iteration == long.MaxValue || (DateTime.Now - startTime).TotalSeconds > secondsForCDSearch)
{
break;
}
iteration++; ellapsedIterations++;
CD_SearchOnce();
if (ImplicantBuffer.Count != implicantsCount)
{
lastChangeIteration = iteration;
ellapsedIterations = 0;
implicantsCount = ImplicantBuffer.Count;
iteration = 0;
}
if (ellapsedIterations / 3 > lastChangeIteration)
{
break;
}
}
void CD_SearchOnce()
{
long[,] varFrequences = new long[2, Length];
string t = new string(Enumerable.Repeat('-', Length).ToArray()); ///текущая импликанта
List <string> trueReduced = True.ToList(); ///сокращённый истинный набор
do
{
t = new string(Enumerable.Repeat('-', Length).ToArray());
do
{
if (!t.Contains('-'))
{
t = new string(Enumerable.Repeat('-', Length).ToArray());
}
t = MostFrequenceVariable();
} while (IntersectFalse(t));
ReduceTrue(trueReduced, t);
if (ImplicantBuffer.Add(t))
{
ExpansionBuffer.Add(t);
}
} while (trueReduced.Count > 0);
//todo вернуть H (сгенерированные импликанты)
string MergeTerms(string first, string second)
{
if (first.Length != second.Length)
{
throw new ArgumentException("Строки разной длины.");
}
StringBuilder sb = new StringBuilder("");
for (int i = 0; i < first.Length; i++)
{
if (first[i] == '-' && second[i] == '-')
{
sb.Append('-');
}
else if ((first[i] == '0' && second[i] == '-') || (first[i] == '-' && second[i] == '0') || (first[i] == '0' && second[i] == '0'))
{
sb.Append('0');
}
else if ((first[i] == '1' && second[i] == '-') || (first[i] == '-' && second[i] == '1') || (first[i] == '1' && second[i] == '1'))
{
sb.Append('1');
}
else
{
throw new ArgumentException("Входные строки не соответствуют требованию");
}
}
return(sb.ToString());
}
string MostFrequenceVariable()
{
long max = -1;
int countMax = 0;
for (int i = 0; i < 2; i++)
{
for (int k = 0; k < Length; k++)
{
varFrequences[i, k] = 0;
}
}
///Составление массива частоты вхождений переменных
for (int i = 0; i < Length; i++)
{
for (int k = 0; k < trueReduced.Count; k++)
{
if (t[i] == '-')
{
if (trueReduced[k][i] == '0')
{
varFrequences[0, i]++;
if (varFrequences[0, i] > max)
{
max = varFrequences[0, i];
countMax = 1;
}
else if (varFrequences[0, i] == max)
{
countMax++;
}
}
else if (trueReduced[k][i] == '1')
{
varFrequences[1, i]++;
if (varFrequences[1, i] > max)
{
max = varFrequences[1, i];
countMax = 1;
}
else if (varFrequences[1, i] == max)
{
countMax++;
}
}
}
}
}
///обработка массива частоты вхождений переменных
List <string> mostFrequencesVariables = new List <string>(countMax); //Набор импликант
StringBuilder sb = new StringBuilder(new string(Enumerable.Repeat('-', Length).ToArray()));
int countImplicants = 0;
bool mutation = (rand.Next(0, 100) > 96);
if (mutation)
{
while (true)
{
int start = rand.Next(Length);
if (varFrequences[1, start] > 0)
{
sb[start] = '1';
string implicant = MergeTerms(t, sb.ToString());
if (!IntersectFalse(implicant))
{
countImplicants++;
}
mostFrequencesVariables.Add(implicant);
sb[start] = '-';
break;
}
else if (varFrequences[0, start] > 0)
{
sb[start] = '0';
string implicant = MergeTerms(t, sb.ToString());
if (!IntersectFalse(implicant))
{
countImplicants++;
}
mostFrequencesVariables.Add(implicant);
sb[start] = '-';
break;
}
start = (start + 1) % Length;
}
}
else
{
for (int i = 0; i < 2; i++)
{
for (int k = 0; k < Length; k++)
{
if (varFrequences[i, k] == max)
{
sb[k] = i.ToString()[0];
string implicant = MergeTerms(t, sb.ToString());
if (!IntersectFalse(implicant))
{
countImplicants++;
}
mostFrequencesVariables.Add(implicant);
sb[k] = '-';
}
}
}
}
if (countImplicants > 0)
{
for (int i = 0; i < mostFrequencesVariables.Count; i++)
{
if (IntersectFalse(mostFrequencesVariables[i]))
{
mostFrequencesVariables.RemoveAt(i--);
}
}
}
return(mostFrequencesVariables[rand.Next(mostFrequencesVariables.Count)]);
}
}
}