// WI: ? make virtual calls
/// <summary>
/// Converts data in the specified binary file to the instance of grid.
/// </summary>
/// <param name="binaryFile">Binary file containing
/// compressed grid.</param>
/// <returns>Instance of a particular grid.</returns>
public static SudokuGrid FromBinary(FileStream binaryFile)
{
SudokuGridConstraints constraints;
SudokuGridMetrics metrics;
byte[] numbersKinds;
string content = SudokuConverter.ToText(binaryFile, out constraints, out numbersKinds, out metrics);
//string content = SudokuConverter.ToText(binaryFile, out constraints, out metrics);
switch (metrics.MaximumNumber)
{
case 9:
var grid = new SudokuGrid9x3(constraints);
grid.IterateLinesXY((x, y) =>
{
var cell = new SudokuGridCell(grid,
new SudokuGridPosition(x, y, false),
byte.Parse(content[metrics.MaximumNumber * y + x].ToString()));
//cell.NumberChanged += (s, e) => grid.OnCellNumberChanged(new CellNumberChangedEventArgs((SudokuGridCell)s));
//grid.cells[y, x] = cell;
AssignNewCell(grid, cell);
});
return grid;
default:
throw new SudokuGridNotSupportedException();
}
}
// TODO: rename
private void RegisterCellAsClue(SudokuGridCell cell)
{
rowsOfNumbers[cell.Position.Y].Add(cell.Number);
columnsOfNumbers[cell.Position.X].Add(cell.Number);
byte x, y;
FindContainingBlock(cell, out x, out y);
blocksOfNumbers[y, x].Add(cell.Number);
--emptyCellsCount;
}
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);
}
// TODO: implement the remaining functionality to find all possible solutions
// TODO: translate in English
// Алгоритм: последовательный проход по клеткам слева направо и вниз
// и усечение мн-ва вариантов цифр,
// которые могут находиться в данной клетке; единственный
// оставшийся вариант подставляется в клетку. Каждый раз,
// как совершается повторный обход доски, должна заполняться
// хотя бы одна клетка. Иначе алгоритм зацикливается,
// и запускается другой алгоритм:
// в первую найденную клетку, имеющую наименьшее кол-во вариантов,
// подставляется наименьший из них (несущественно) и поиск продолжается
// на специальной доске assumptionsGrid по исходному
// алгоритму: если полученное решение непротиворечиво, то
// оно становится окончательным. Иначе: а) если получаем
// противоречие, то исходная подстановка неверна и,
// вернувшись к точке осущствления подстановки,
// подставляем другую цифру, вновь применяя исохдный алгоритм;
// б) если получаем зацикливание, то снова находим эл-т
// с наименьшим кол-вом вариантов, подставляем один из них
// и применяем исходный алгоритм.
// TODO: protected override List<SudokuGridCell[,]> SearchSolutions()
protected override bool SearchSolutionDebug()
{
forbiddenCandidates.Clear();
Grid.IterateLinesXY((x, y) =>
{
SudokuGridCell cell = Grid.Cells[y, x];
if (cell.IsClue)
{
RegisterCellAsClue(cell);
}
});
var resultCells = _SearchSolutionDebug();
if (resultCells == null)
{
return(false);
}
Grid.Cells = resultCells;
Reset();
return(true);
}
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);
}
// WI: consider moving to cell class
private void FindContainingBlock(SudokuGridCell cell, out byte x, out byte y)
{
x = (byte)(cell.Position.X / cell.ParentGrid.Metrics.BlockWidth);
y = (byte)(cell.Position.Y / cell.ParentGrid.Metrics.BlockHeight);
}
// 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;
}
public CellNumberChangedEventArgs(SudokuGridCell cell) { this.cell = cell; }
// TODO: rename
private void RegisterCellAsClue(SudokuGridCell cell)
{
rowsOfNumbers[cell.Position.Y].Add(cell.Number);
columnsOfNumbers[cell.Position.X].Add(cell.Number);
byte x, y;
FindContainingBlock(cell, out x, out y);
blocksOfNumbers[y, x].Add(cell.Number);
--emptyCellsCount;
}
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;
}
// WI: consider moving to cell class
private void FindContainingBlock(SudokuGridCell cell, out byte x, out byte y)
{
x = (byte)(cell.Position.X / cell.ParentGrid.Metrics.BlockWidth);
y = (byte)(cell.Position.Y / cell.ParentGrid.Metrics.BlockHeight);
}