public static int getScatteredPhraseEntries(string phrase, string text)
{
if (String.IsNullOrEmpty(phrase))
throw new ArgumentException("Phrase is null or empty!");
if (String.IsNullOrEmpty(text))
throw new ArgumentException("Text is null or empty!");
var root = new TreeNode(0, phrase.Length - 1, new PhraseCharSet(phrase));
for (int symbolIndex = 0; symbolIndex < text.Length; symbolIndex++)
root.getNextSymbol(text.ElementAt(symbolIndex));
return root.getVariantsNumber();
}
public void getNextSymbol(char nextTextCharacter)
{
if (!phraseCharSet.isPhraseContainsChar(nextTextCharacter))
return;//phrase do not even contain this char, so it is not any interesting for us - return
//if we face the symbol, which position in phrase match our node's position
if (phraseCharSet.isCharMatchesPosition(nextTextCharacter, indexOfTheSymbolInPhrase))
{
//if we do not have nextSymbolNode yet, it means, that it is only one more same char in a row - simply increment symbolsCollected
if (nextSymbolNode == null)
{
//fix for phrases with two or more symbols in a row - we need to check matching for a position of next symbol
if (symbolsCollected == 1 && phraseCharSet.isCharMatchesPosition(nextTextCharacter, indexOfTheSymbolInPhrase + 1))
{
//if yes, we must initialize nextSymbolNode as current symbol can be the next, not current symbol as well
nextSymbolNode = new TreeNode(indexOfTheSymbolInPhrase + 1, maxIndex, phraseCharSet);
nextSymbolNode.getNextSymbol(nextTextCharacter);
//and if we now have nextSymbolNode, we can instantiate sameSymbolNode with this symbol as well
sameSymbolNode = new TreeNode(indexOfTheSymbolInPhrase, maxIndex, phraseCharSet);
sameSymbolNode.getNextSymbol(nextTextCharacter);
}
else
{
symbolsCollected++;
}
}
else
{
//this means that ve already had a set of at least next characters before we reach current symbol
//in case there is no sameSymbolNode yet, we will create it as current symbol can create new branch of possibilities
if (sameSymbolNode == null)
sameSymbolNode = new TreeNode(indexOfTheSymbolInPhrase, maxIndex, phraseCharSet);
//and send symbol to it
sameSymbolNode.getNextSymbol(nextTextCharacter);
//and as symbols in phrase can duplicate, we send symbol to nextSymbolNode as symbol can find a place for him further in the branch
nextSymbolNode.getNextSymbol(nextTextCharacter);
}
return;
}
//if we face the symbol, that match the symbol with position in phrase that is ahead of us by 1
if (phraseCharSet.isCharMatchesPosition(nextTextCharacter, indexOfTheSymbolInPhrase + 1))
{
//if we do not have nextSymbolNode yet, it means it is high time to create it - we faced the symbol, that matches next position in phrase
if (nextSymbolNode == null)
nextSymbolNode = new TreeNode(indexOfTheSymbolInPhrase + 1, maxIndex, phraseCharSet);
else
{
//and if sameSymbolNode existed, will send symbol there
if (sameSymbolNode != null)
sameSymbolNode.getNextSymbol(nextTextCharacter);
}
//as we already have nextSymbolNode, we just send symbol to it, nextSymbolNode will take care of it
nextSymbolNode.getNextSymbol(nextTextCharacter);
return;
}
//if symbol does not match any of mentioned conditions, will send it to children anyway
if (nextSymbolNode != null)
{
nextSymbolNode.getNextSymbol(nextTextCharacter);
if (sameSymbolNode != null)
sameSymbolNode.getNextSymbol(nextTextCharacter);
}
}