public SudokuSolvingIterationAssumptionTechnique(SudokuGrid grid)
: base(grid)
{
rowsOfNumbers = new SortedSet<byte>[Grid.Metrics.MaximumNumber];
columnsOfNumbers = new SortedSet<byte>[Grid.Metrics.MaximumNumber];
Grid.IterateLine(i =>
{
rowsOfNumbers[i] = new SortedSet<byte>();
columnsOfNumbers[i] = new SortedSet<byte>();
});
blocksOfNumbers = new SortedSet<byte>[Grid.Metrics.MaximumNumber / Grid.Metrics.BlockHeight,
Grid.Metrics.MaximumNumber / Grid.Metrics.BlockWidth];
Grid.IterateBlocksXY((x, y) =>
{
blocksOfNumbers[y, x] = new SortedSet<byte>();
});
forbiddenCandidates = new SortedSet<byte>();
Grid.CellNumberChanged += (s, e) => RegisterCellAsClue(e.Cell);
emptyCellsCount = Grid.Metrics.CellsTotal;
//Grid.IterateLinesXY((x, y) =>
//{
// SudokuGridCell cell = Grid.Cells[y, x];
// if (cell.IsClue)
// {
// RegisterCellAsClue(cell);
// }
//});
}
/// <summary>
/// Initializes a new instance of grid cell.
/// </summary>
/// <param name="parentGrid">The grid including this cell.</param>
/// <param name="position">The cell's position at the specified grid.</param>
/// <param name="number">The number substituted into this cell.</param>
internal SudokuGridCell(SudokuGrid parentGrid, SudokuGridPosition position, byte number)
{
ParentGrid = parentGrid;
Position = position;
if (number == EmptyCellNumber)
{
this.number = number;
Candidates = new CandidatesSortedSet(this);
Candidates.ContradictionFound += (s, e) => ContradictionFound = true;
switch (parentGrid.Constraints)
{
case SudokuGridConstraints.Traditional:
for (byte i = 1; i <= parentGrid.Metrics.MaximumNumber; ++i)
{
Candidates.Add(i);
}
break;
case SudokuGridConstraints.Diagonal:
break;
case SudokuGridConstraints.Even:
break;
case SudokuGridConstraints.Odd:
break;
case SudokuGridConstraints.Areas:
break;
}
}
else
{
Number = number;
}
}
private static void ShowSolution(SudokuGrid grid)
{
Console.WriteLine("Found solution:");
Console.WriteLine();
var sb = new StringBuilder();
char horDelim = '-';
char vertDelim = '|';
for (byte i = 0; i < 25; ++i)
{
sb.Append(horDelim);
}
string horDelims = sb.ToString();
sb.Clear();
for (int i = 0; i < 2; ++i)
{
sb.Append(" ");
}
string leftOffset = sb.ToString();
var defaultForeColor = Console.ForegroundColor;
Action<string> writeColoredDelim = (data) =>
{
Console.ForegroundColor = ConsoleColor.DarkGray;
Console.Write(data);
Console.ForegroundColor = defaultForeColor;
};
writeColoredDelim(leftOffset + horDelims + "\n");
for (byte i = 0; i < grid.Metrics.MaximumNumber; ++i)
{
writeColoredDelim(leftOffset + vertDelim);
for (byte j = 0; j < grid.Metrics.MaximumNumber; ++j)
{
Console.Write(" " + grid[i, j]);
if ((j + 1) % 3 == 0)
{
writeColoredDelim(" " + vertDelim);
}
}
Console.WriteLine();
if ((i + 1) % 3 == 0)
{
writeColoredDelim(leftOffset + horDelims + "\n");
}
}
Console.WriteLine();
}
// BUG: used to avoid buggy duplicate-code decision in solver classes -- get rid of as soon as possible
internal static void AssignNewCell(SudokuGrid grid, SudokuGridCell cell)
{
cell.NumberChanged += (s, e) => grid.OnCellNumberChanged(new CellNumberChangedEventArgs((SudokuGridCell)s));
grid.cells[cell.Position.Y, cell.Position.X] = cell;
}
// BUG: used to avoid buggy duplicate-code decision in solver classes -- get rid of as soon as possible
internal static void AssignNewCell(SudokuGrid grid, SudokuGridCell cell)
{
cell.NumberChanged += (s, e) => grid.OnCellNumberChanged(new CellNumberChangedEventArgs((SudokuGridCell)s));
grid.cells[cell.Position.Y, cell.Position.X] = cell;
}
protected SudokuSolvingTechnique(SudokuGrid grid)
{
Grid = grid;
// BUG: the solver changes cells' collection via exactly the same pointer
initialGridCells = grid.Cells;
}
private SudokuGridCell[,] MakeAssumptionInCell(ref SudokuGridPosition? minCandidatesCellPos)
{
if (!minCandidatesCellPos.HasValue)
{
// TODO: optimize: lookup that kind of cell repetitively when its number of candidates changes (decreases): compare against the minimum value from a variable (where to put it?)
minCandidatesCellPos = FindFirstCellWithMinimumCandidates(Grid).Position;
}
var minCandidatesCell = Grid.Cells[minCandidatesCellPos.Value.Y, minCandidatesCellPos.Value.X];
byte assumedNumber = minCandidatesCell.Candidates.ToArray()[0];
assumptionsGrid = (SudokuGrid)Grid.GetType()
.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic,
null, CallingConventions.HasThis, new[] { typeof(SudokuGridConstraints) }, null)
.Invoke(new [] { (object)Grid.Constraints });
// BUG: !!! as we use the standard grid here, which was not initially intended to be used anywhere except for decode-and-construct scenarios, by the time we reach this code the assumptionsGrid's cells are not initialized yet -- consider introducing some sort of temporary 'grid' (most probably, a kind of 'cells-only layer'). For that reason one of the ctor's code sections was moved into the Reset() method
var assumptionsGridSolver = new SudokuSolvingIterationAssumptionTechnique(assumptionsGrid);
// WI: cell-to-cell iteration is a very intensive process -- use cells array cloning instead with targeted minCandidatesCell... altering
var minCandidatesCellPosCopy = minCandidatesCellPos.Value;
assumptionsGrid.IterateLinesXY((x, y) =>
{
SudokuGridCell currCell;
var currPos = new SudokuGridPosition(x, y, false);
if (currPos.Equals(minCandidatesCellPosCopy))
{
currCell = new SudokuGridCell(assumptionsGrid, currPos, assumedNumber);
assumptionsGridSolver.lastFilledPos = currPos;
assumptionsGridSolver.currCheckingPos = currPos;
assumptionsGridSolver.currCheckingPos.Shift(1, assumptionsGrid.Metrics);
}
else
{
currCell = new SudokuGridCell(assumptionsGrid, currPos, Grid.Cells[y, x].Number);
if (currCell.Candidates != null)
{
// just to bring into accord with the latest value from the 'parent' grid
currCell.Candidates.IntersectWith(Grid.Cells[y, x].Candidates);
}
}
SudokuGrid.AssignNewCell(assumptionsGrid, currCell);
//assumptionsGrid.Cells[y, x] = currCell;
});
//List<SudokuGridCell[,]> assumptionGridSolutuons = assumptionGridSolver.SearchSolutions();
//if (assumptionGridSolutuons.Count > 0) // correct assumption was made
//{
// return assumptionsGrid.Cells;
//}
//SudokuGridCell[,] solution;
if (assumptionsGridSolver.SearchSolutionDebug()) // correct assumption was made
{
//return solution;
return assumptionsGrid.Cells;
}
// incorrect assumption was made (executes on contradiction only)
minCandidatesCell.Candidates.Remove(assumedNumber);
// if there were only two candidates, with assumedNumber being one of them, then the remaining one is a clue
if (minCandidatesCell.IsClue)
{
minCandidatesCellPos = null;
var newPos = new SudokuGridPosition(minCandidatesCell.Position.X, minCandidatesCell.Position.Y, false);
lastFilledPos = newPos;
currCheckingPos = newPos;
currCheckingPos.Shift(1, Grid.Metrics);
}
return null;
}
private SudokuGridCell FindFirstCellWithMinimumCandidates(SudokuGrid grid)
{
byte minCandidates = grid.Metrics.MaximumNumber;
SudokuGridCell minCandidatesCell = null;
grid.IterateLinesXY((x, y) =>
{
var currCell = grid.Cells[y, x];
if (currCell.Candidates != null &&
currCell.Candidates.Count < minCandidates)
{
minCandidates = (byte)currCell.Candidates.Count;
minCandidatesCell = currCell;
}
});
return minCandidatesCell;
}
public static byte[] ToBinary(FileStream textFile, SudokuGrid grid,
SudokuConvertionAlgorithm algorithm)
{
string content;
textFile.Position = 0;
using (var sr = new StreamReader(textFile))
{
content = sr.ReadToEnd();
}
textFile.Position = 0;
return ToBinary(content, algorithm, grid.Constraints, grid.Metrics);
}
public static byte[] ToBinary(SudokuGrid grid, SudokuConvertionAlgorithm algorithm)
{
var sb = new StringBuilder(grid.Metrics.CellsTotal);
grid.IterateLinesXY((x, y) => sb.Append(grid.Cells[y, x].Number));
return ToBinary(sb.ToString(), algorithm, grid.Constraints, grid.Metrics);
}
