protected Result Process(SudokuField sudokuField, int row, int column)
{
SudokuElement sudokuElement = sudokuField.GetSudokuElement(row, column);
HashSet <int> existingNumbers = GetNumbersFromSudokuSection(sudokuField, row, column);
foreach (int number in existingNumbers)
{
_ = sudokuElement.RemoveCandidate(number);
}
return(AddNumber(sudokuElement));
}
public new SolverResult Process(SudokuField sudokuField)
{
_sudokuFieldCopy = sudokuField;
Stack <StackElement> stackElements = new Stack <StackElement>();
StackElement stackElement;
Result result = Result.None;
int index;
while (true)
{
switch (result)
{
case Result.FullFilled:
return(new SolverResult(Result.FullFilled, _sudokuFieldCopy));
case Result.Error:
bool loop = true;
do
{
if (stackElements.Count == 0)
{
return(new SolverResult(Result.Error));
}
stackElement = stackElements.Pop();
index = stackElement.Index + 1;
if (index < stackElement.GetCandidateSize())
{
_sudokuFieldCopy = stackElement.SudokuField;
_sudokuElement = stackElement.SudokuElement;
if (PutOnStack(stackElements, index) == Result.Error)
{
return(new SolverResult(Result.Error));
}
loop = false;
}
else
{
loop = true;
}
} while (loop);
break;
default:
_sudokuElement = FindFirstEmpty(_sudokuFieldCopy);
if (PutOnStack(stackElements, 0) == Result.Error)
{
return(new SolverResult(Result.Error));
}
break;
}
result = base.Process(_sudokuFieldCopy);
}
}
private Result AddNumber(SudokuElement sudokuElement)
{
var size = sudokuElement.GetCandidatesSize();
switch (size)
{
case 0:
return(Result.Error);
case 1:
sudokuElement.Number = sudokuElement.GetFirstCandidate();
sudokuElement.FontColor = Data.SingleColor;
return(Result.Added);
default:
return(Result.None);
}
}
private Result PutOnStack(Stack <StackElement> stack, int index)
{
StackElement stackElement = new StackElement(_sudokuFieldCopy, _sudokuElement, index);
stack.Push(stackElement);
_sudokuFieldCopy = _sudokuFieldCopy.DeepCopy();
_sudokuElement = FindFirstEmpty(_sudokuFieldCopy);
if (_sudokuElement == null)
{
return(Result.Error);
}
int number = _sudokuElement.GetCandidate(index);
_sudokuElement.Number = number;
_sudokuElement.FontColor = Data.BackTrackColor;
return(Result.None);
}
protected bool AddUniqueFromExisting(ImmutableSortedDictionary <Position, SudokuElement> elements, SudokuElement sudokuElement, HashSet <int> existngNumbers)
{
var result = false;
var number = FindUniqueCandidates(elements)
.Where(n => sudokuElement.ContainCandidate(n))
.Where(n => !existngNumbers.Contains(n))
.DefaultIfEmpty(0)
.First();
if (number != 0)
{
sudokuElement.Number = number;
sudokuElement.FontColor = Data.UniqueColor;
result = true;
}
return(result);
}
public int GetCandidateSize()
{
return(SudokuElement.GetCandidatesSize());
}
public StackElement(SudokuField sudokuField, SudokuElement sudokuElement, int index)
{
SudokuField = sudokuField;
SudokuElement = sudokuElement;
Index = index;
}
