private static IEnumerable <Words> SentenceAnagramsIter(Occurrences occurrences)
{
var occurrencesAsList = occurrences.ToList();
if (!occurrencesAsList.Any())
{
yield return(new List <Word>());
yield break;
}
foreach (var combination in Combinations(occurrencesAsList))
{
var combinationAsList = combination.ToList();
var remainingOccurrences = Subtract(occurrencesAsList, combinationAsList).ToList();
foreach (var word in WordsForCombination(combinationAsList))
{
foreach (var innerSentence in _sentenceAnagramsIterFunc(remainingOccurrences))
{
var sentence = new List <Word> {
word
};
sentence.AddRange(innerSentence);
yield return(sentence);
}
}
}
}
private static IEnumerable <Occurrences> Combinations(Occurrences occurrences)
{
var occurrencesAsList = occurrences.ToList();
if (!occurrencesAsList.Any())
{
yield return(new List <Tuple <char, int> >());
yield break;
}
var hd = occurrencesAsList.First();
var tl = occurrencesAsList.Skip(1);
var c = hd.Item1;
var n = hd.Item2;
var tlCombinations = Combinations(tl).ToList();
foreach (var x in Enumerable.Range(0, n + 1))
{
var first = (x > 0) ? Tuple.Create(c, x) : null;
foreach (var others in tlCombinations)
{
var y = new List <Tuple <char, int> >();
if (first != null)
{
y.Add(first);
}
y.AddRange(others);
yield return(y);
}
}
}
