internal IEnumerable <SymmetricGroup> Join(
Dictionary <char, List <Word> > words1,
Dictionary <char, List <Word> > words2,
DifferenceNode differenceRoot1,
DifferenceNode differenceRoot2)
{
int len1 = Sentence.Length;
int len2 = ReverseSentence.Length;
if (len1 < len2)
{
List <Word> words;
if (!words1.TryGetValue(Difference.CharAtFromEnd(0), out words))
{
yield break;
}
foreach (Word word in words)
{
bool canJoin = true;
int charCountToCheck = Math.Min(word.OriginWord.Length, len2 - len1);
for (int i = 1; i < charCountToCheck; i++)
{
if (word.OriginWord[i] != Difference.CharAtFromEnd(i))
{
canJoin = false;
break;
}
}
if (canJoin)
{
Difference newDifference;
if (len2 - len1 >= word.OriginWord.Length)
{
string baseWord = ReverseSentence.Words.First.OriginWord;
newDifference = new Difference(baseWord, 0, len2 - len1 - word.OriginWord.Length);
if (!differenceRoot2.AddReverse(newDifference, 0))
{
continue;
}
}
else
{
newDifference = new Difference(word.OriginWord, len2 - len1, word.OriginWord.Length - len2 + len1);
if (!differenceRoot1.Add(newDifference, 0))
{
continue;
}
}
yield return(new SymmetricGroup(Sentence.Append(word), ReverseSentence, newDifference));
}
}
}
if (len1 > len2)
{
List <Word> words;
if (!words2.TryGetValue(Difference.CharAt(0), out words))
{
yield break;
}
foreach (Word word in words)
{
bool canJoin = true;
int charCountToCheck = Math.Min(word.OriginWord.Length, len1 - len2);
for (int i = 1; i < charCountToCheck; i++)
{
if (word.OriginWord[word.OriginWord.Length - 1 - i] != Difference.CharAt(i))
{
canJoin = false;
break;
}
}
if (canJoin)
{
Difference newDifference;
if (len1 - len2 >= word.OriginWord.Length)
{
string baseWord = Sentence.Words.Last.OriginWord;
newDifference = new Difference(baseWord, baseWord.Length - len1 + len2 + word.OriginWord.Length, len1 - len2 - word.OriginWord.Length);
if (!differenceRoot1.Add(newDifference, 0))
{
continue;
}
}
else
{
newDifference = new Difference(word.OriginWord, 0, word.OriginWord.Length - len1 + len2);
if (!differenceRoot2.AddReverse(newDifference, 0))
{
continue;
}
}
yield return(new SymmetricGroup(Sentence, ReverseSentence.Prepend(word), newDifference));
}
}
}
}
