public long f(int n)
{
WordSequence mainSeq = this.WordSeqs[this.MainID];
while (mainSeq.Counts.Count <= n)
{
this.AllNextCounts();
}
return(mainSeq.Counts[n]);
}
private void NextCount(WordSequence wordSeq)
{
int index = wordSeq.Counts.Count - 1;
long nextTerm = 0;
int parentID;
long parentTerm;
int terms = wordSeq.Recursion.IDs.Count;
for (int i = 0; i < terms; i++)
{
parentID = wordSeq.Recursion.IDs[i];
parentTerm = this.WordSeqs[parentID].Counts[index];
nextTerm += wordSeq.Recursion.Coefficients[i] * parentTerm;
}
wordSeq.Counts.Add(nextTerm);
//if (index>7)// && wordSeq.KeywordCount>0)
// Console.WriteLine($"i={index+1} id={wordSeq.ID} ending={wordSeq.Ending} #keys={wordSeq.KeywordCount} count(i)={nextTerm}");
}
// Generates the list of word-sequences, one for each pair (keyword subset, subkeyword),
// starting with (empty set, empty word).
// Returns the ID of the main sequence, with all Keywords present and no specific ending.
private int GenerateWordSeqs()
{
this.WordSeqs = new List <WordSequence>();
// First generate the bare counters.
int iD;
bool[] keywordPresence;
int numberOfSubsets = (int)Math.Pow(2, this.Keywords.Length);
int mainID = (numberOfSubsets - 1) * this.SubKeywords.Count;
WordSequence newWordSeq;
for (int i = 0; i < numberOfSubsets; i++)
{
keywordPresence = this.intToBools(i, this.Keywords.Length);
foreach (string subkey in this.SubKeywords)
{
iD = this.WordSeqs.Count;
newWordSeq = new WordSequence(subkey, keywordPresence, iD);
this.WordSeqs.Add(newWordSeq);
}
}
// Then generate the recurrence relations.
// WARNING: Assumes no keyword is a final subword of another
// (i.e., no two keywords can be completed simultaneously with the addition of 1 letter).
WordSequence child;
WordSequence parent;
string primaryParentEnding;
int primaryParentCoefficient;
int primaryParentKeyInt;
bool[] possibleKeys;
List <string> possibleKeysSansEnd;
int missingKeywordIndex;
string missingKeyword;
for (iD = 0; iD < this.WordSeqs.Count; iD++)
{
child = this.WordSeqs[iD];
primaryParentEnding = string.Empty;
primaryParentCoefficient = this.Alphabet.Length;
primaryParentKeyInt = this.boolsToInt(child.KeywordPresence);
possibleKeys = new bool[this.Keywords.Length];
possibleKeysSansEnd = new List <string>();
/*if (iD == 0)
* child.Recursion.AddRecurranceTerm(iD, primaryParentCoefficient);
* else {*/
if (child.Ending != string.Empty)
{
primaryParentCoefficient = 1;
if (child.Ending.Length > 1)
{
primaryParentEnding = child.Ending.Substring(0, child.Ending.Length - 1);
}
}
// Identify which /*counted*/ keywords are completed with the current child's Ending.
for (int i = 0; i < this.Keywords.Length; i++)
{
if (/*child.KeywordPresence[i] &&*/ this.HasFinalSubstring(this.Keywords[i], child.Ending))
{
possibleKeys[i] = true;
possibleKeysSansEnd.Add(this.Keywords[i].Substring(0, this.Keywords[i].Length - 1));
}
}
for (int j = 0; j < this.WordSeqs.Count; j++)
{
parent = this.WordSeqs[j];
if (parent.Ending == primaryParentEnding)
{
// First recurrence case is the primary parent, with:
// * the same set of keywords
// * ending keyword same as child's without it's final letter removed.
if (this.boolsToInt(parent.KeywordPresence) == primaryParentKeyInt)
{
child.Recursion.AddRecurranceTerm(j, primaryParentCoefficient);
}
}
else if (possibleKeysSansEnd.Contains(parent.Ending))
{
// Second recurrence case is subtracted to cancel unwanted new words.
if (this.boolsToInt(parent.KeywordPresence) == primaryParentKeyInt)
{
child.Recursion.AddRecurranceTerm(j, -1);
}
// Third recurrence case has exactly one keyword missing from the set of keywords,
// and that keyword is terminated by the child's ending,
// and with ending word that keyword without it's final letter.
else
{
missingKeywordIndex = this.MissingIndex(child.KeywordPresence, parent.KeywordPresence);
if (missingKeywordIndex >= 0 && possibleKeys[missingKeywordIndex])
{
missingKeyword = this.Keywords[missingKeywordIndex];
if (missingKeyword.Substring(0, missingKeyword.Length - 1) == parent.Ending)
{
child.Recursion.AddRecurranceTerm(j, 1);
}
}
}
}
}
/*}*/
//Console.WriteLine($"iD={iD} #keywords={child.KeywordCount} ending={child.Ending} #possible={possibleKeysSansEnd.Count} #parents={child.Recursion.IDs.Count} primaryParentPresence={primaryParentKeyInt} primaryParentEnding={primaryParentEnding} primaryParentCoef={primaryParentCoefficient}");
/*if (possibleKeysSansEnd.Count == this.Keywords.Length) {
* foreach (int recID in child.Recursion.IDs) Console.WriteLine(recID);
* foreach (int recCoef in child.Recursion.Coefficients) Console.WriteLine(recCoef);
* }*/
}
return(mainID);
}