public IEnumerable <Placement> FindPlacements(Gaddag words)
{
if (Grid.IsEmpty())
{
foreach (Gaddag word in words.FindAllWords(Bank))
{
Bank after = new Bank(Bank);
after.TakeWord(word.word);
yield return(new Placement(word.word, 0, 0, false, after));
yield return(new Placement(word.word, 0, 0, true, after));
}
yield break;
}
IEnumerable <Placement> FindPlacementsOriented(bool vertical)
{
int start = (vertical ? Grid.LeftmostColumnIndex : Grid.TopRowIndex);
int end = (vertical ? Grid.RightmostColumnIndex : Grid.BottomRowIndex);
for (int i = start; i <= end; ++i)
{
if (Grid.IsEmptyLine(i, vertical))
{
continue;
}
foreach (Placement placement in Grid.FindLinePlacements(i, vertical, Bank, words))
{
yield return(placement);
}
}
}
foreach (Placement placement in FindPlacementsOriented(false))
{
yield return(placement);
}
foreach (Placement placement in FindPlacementsOriented(true))
{
yield return(placement);
}
}
public IEnumerable <Placement> FindLinePlacementsFrom(int lineIndex, int start, int frontLeeway, bool vertical, Bank startingBank, Gaddag words)
{
Dictionary <int, Line> axis = vertical ? columns : rows;
Line line = axis[lineIndex];
Line[] neighbors = new Line[2];
neighbors[0] = GetLineLazy(axis, lineIndex - 1);
neighbors[1] = GetLineLazy(axis, lineIndex + 1);
Stack <(Gaddag, int, Bank)> nodes = new Stack <(Gaddag, int, Bank)>();
nodes.Push((words, start, startingBank));
while (nodes.Count != 0)
{
(Gaddag node, int index, Bank bank) = nodes.Pop();
if (line.IsEmptyAt(index))
{
if (!(neighbors[0].IsEmptyAt(index) && neighbors[1].IsEmptyAt(index)))
{
continue;
}
for (char c = 'a'; c <= 'z'; ++c)
{
if (!bank.HasLetter(c) || node[c] == null)
{
continue;
}
Bank after = new Bank(bank);
after.TakeLetter(c);
nodes.Push((node[c], index - 1, after));
}
if (node['{'] != null)
{
foreach (Gaddag word in node['{'].FindAllWords(bank))
{
if (word.word.Length - word.reversePoint >= frontLeeway)
{
continue;
}
Bank after = new Bank(bank);
after.TakeWord(word.word.Substring(word.reversePoint + 1));
if (Enumerable.SequenceEqual(startingBank.letters, after.letters))
{
continue;
}
yield return(new Placement(word.word, lineIndex, start - word.reversePoint, vertical, after));
}
}
}
else
{
char c = line[index];
if (node[c] != null)
{
nodes.Push((node[c], index - 1, bank));
}
}
}
}