public void Solve()
{
BasicSolve();
if (IsLegal && !IsSolved)
{
var undeterminedCells =
MatrixIterator
.Where(cell => !cell.IsDetermined);
SudokuCell speculationTarget = undeterminedCells
.First(cell => cell.Candidates.Count ==
undeterminedCells.Min(c => c.Candidates.Count));
Random rng = new Random();
var shuffledCandidates = speculationTarget.Candidates
.OrderBy(c => rng.Next());
foreach (int candidate in shuffledCandidates)
{
SudokuBoard speculativeBoard = new SudokuBoard(this);
speculativeBoard.SetCell(
cellRow: speculationTarget.Row,
cellColumn: speculationTarget.Column,
valueToSet: candidate);
speculativeBoard.Solve();
if (speculativeBoard.IsLegal && speculativeBoard.IsSolved)
{
this.Copy(speculativeBoard);
return;
}
}
}
}
public async Task ParallelSolve(int branchingDepth = -1)
{
if (branchingDepth == 0)
{
Solve();
return;
}
BasicSolve();
if (IsLegal && !IsSolved)
{
var undeterminedCells =
MatrixIterator
.Where(cell => !cell.IsDetermined);
SudokuCell speculationTarget = undeterminedCells
.First(cell => cell.Candidates.Count ==
undeterminedCells.Min(c => c.Candidates.Count));
var tokenSource = new CancellationTokenSource();
List <Task <SudokuBoard> > speculationTasks = new List <Task <SudokuBoard> >();
foreach (int candidate in speculationTarget.Candidates)
{
SudokuBoard speculativeBoard = new SudokuBoard(this);
speculativeBoard.SetCell(
cellRow: speculationTarget.Row,
cellColumn: speculationTarget.Column,
valueToSet: candidate);
var token = tokenSource.Token;
speculationTasks.Add(
Task.Factory.StartNew(() =>
{
speculativeBoard
.ParallelSolve(branchingDepth > 0 ? branchingDepth - 1 : branchingDepth)
.Wait(token);
return(speculativeBoard);
},
token)
);
}
while (speculationTasks.Count > 0)
{
Task <SudokuBoard> completedTask = await Task.WhenAny(speculationTasks);
SudokuBoard speculativeBoard = completedTask.Result;
if (speculativeBoard.IsLegal && speculativeBoard.IsSolved)
{
tokenSource.Cancel();
this.Copy(speculativeBoard);
return;
}
speculationTasks.Remove(completedTask);
}
}
}
static void Main()
{
var array = new int[] { 1, 2, 3, 4 };
var matrix = new int[, ]
{
{ 5, 6, 7 },
{ 8, 9, 10 }
};
var arrayIterator = new ArrayIterator(array);
var matrixIterator = new MatrixIterator(matrix);
Print(arrayIterator);
Print(matrixIterator);
}
public void RecomputeCandidates()
{
MatrixIterator
.Where(cell => !cell.IsDetermined)
.ToList()
.ForEach(cell => cell.Clear());
MatrixIterator
.Where(cell => cell.IsDetermined)
.ToList()
.ForEach(cell => UpdateBoardCandidates(
sourceRow: cell.Row,
sourceColumn: cell.Column,
valueToRemove: (int)cell.Value));
}
static void Main(string[] args)
{
Iterator <int> collection1 = new LinkedListIterator <int>(new Node <int>(1, new Node <int>(2, new Node <int>(3, new Empty <int>()))));
PrintCollection(collection1);
Iterator <int> collection2 = new ArrayIterator <int>(new int[] { 9, 10, 11, -1 });
PrintCollection(collection2);
int[][] tmp_collection3 = new int[3][];
tmp_collection3[0] = new int[] { 3, 2, 1 };
tmp_collection3[1] = new int[] { 2, 1, 3 };
tmp_collection3[2] = new int[] { 1, 3, 2 };
Iterator <int> collection3 = new MatrixIterator <int>(tmp_collection3, 3, 3);
PrintCollection(collection3);
Iterator <int> collection4 = new NaturalNumbers();
PrintCollection(collection4);
}
public int SetNakedCandidateCells()
{
int nCellsSet = 0;
MatrixIterator
.Where(cell => cell.HasNakedCandidate())
.ToList()
.ForEach(
cell =>
{
if (cell.Candidates.Count == 1)
{
SetCell(
cellRow: cell.Row,
cellColumn: cell.Column,
valueToSet: cell.Candidates.First());
nCellsSet++;
}
});
return(nCellsSet);
}
