public static Grid Solve(Grid grid)
{
IList solutions = Solve((Grid)grid.Clone(), 1);
if (solutions.Count == 0)
{
return null;
}
else
{
return (Grid)solutions[0];
}
}
public static Grid Solve(Grid grid)
{
IList solutions = Solve((Grid)grid.Clone(), 1);
if (solutions.Count == 0)
{
return(null);
}
else
{
return((Grid)solutions[0]);
}
}
public static bool ValidNumberPlace(Grid grid)
{
// Check only one solution exists
IList solutions = Solve((Grid)grid.Clone(), 2);
if (solutions.Count == 1)
{
return(true);
}
// Either unsolvable or multiple solutions
return(false);
}
public static bool ValidNumberPlace(Grid grid)
{
// Check only one solution exists
IList solutions = Solve((Grid)grid.Clone(), 2);
if (solutions.Count == 1)
{
return true;
}
// Either unsolvable or multiple solutions
return false;
}
/// <summary>
/// rate a grid
/// returns it as int
/// the lower the harder
/// </summary>
/// <param name="grid">Grid</param>
/// <returns></returns>
public static int Rate(Grid gridOrg)
{
Grid grid = (Grid)gridOrg.Clone();
int rate = 0;
rateAll = 0;
// for(int trys = 0; trys<10;trys++)
// {
// grid = (Grid)gridOrg.Clone();
// rate = 0;
while (grid.CountFilledCells() < (grid.CellsInRow * grid.CellsInRow))
{
int cand = FindUniqueCandidates(grid);
rate += cand;
if (cand > 0)
{
int candidateIndex = random.Next(cand);
int m = -1, i = 0, j = 0, candidateRow = 0, candidateCol = 0;
for (i = 0; i < 9 && m < candidateIndex; i++)
{
for (j = 0; j < 9 && m < candidateIndex; j++)
{
if (grid.uniqueCandidates[i, j] != 0)
{
m++;
if (m == candidateIndex)
{
candidateRow = i;
candidateCol = j;
}
}
}
}
grid.cells[candidateRow, candidateCol] = grid.uniqueCandidates[candidateRow, candidateCol];
}
else
{
//rate = rate - ((grid.BlocksAcross * grid.BlocksAcross) - grid.CountFilledCells());
//no more unique cells -> difficult grid
rate = grid.CountFilledCells();
break;
}
}
// rateAll += rate;
// MediaPortal.GUI.Library.Log.WriteFile(MediaPortal.GUI.Library.LogType.Log, "Soduko Rate end "+trys+" notes: {0}", rate);
// }
return(rate);
}
public static Grid Generate(int blocksAcross)
{
// First generate a random completed grid that is valid
Grid empty = new Grid(blocksAcross);
Grid solution = Solve(empty);
Grid puzzle = (Grid)solution.Clone();
return(Minimize(puzzle));
/*
* Random random = new Random(DateTime.Now.Millisecond);
*
* IList removeCandidates = new ArrayList();
* for (int cellNumber = 1; cellNumber <= 81; cellNumber++)
* {
* removeCandidates.Add(cellNumber);
* }
*
* while (removeCandidates.Count > 0)
* {
* int removeIndex = random.Next(removeCandidates.Count);
* int row = removeIndex / puzzle.CellsInRow;
* int column = removeIndex % puzzle.CellsInRow;
*
* if (puzzle.cells[row, column] != 0)
* {
* int value = puzzle.cells[row, column];
* puzzle.cells[row, column] = 0;
* IList solutions = Solve((Grid)puzzle.Clone(), 2);
* if (solutions.Count == 2 || solutions.Count == 0)
* {
* puzzle.cells[row, column] = value;
* }
* else
* {
* cellsRemoved;
* }
* }
* }
*
* IList solns = Solve((Grid)puzzle.Clone(), 10);
* return puzzle;
*/
}
public static bool CheckMinimality(Grid grid)
{
Grid temp = (Grid)grid.Clone();
for (int row = 0; row < temp.CellsInRow; row++)
{
for (int column = 0; column < temp.CellsInRow; column++)
{
if (temp.cells[row, column] != 0)
{
int value = temp.cells[row, column];
temp.cells[row, column] = 0;
if (ValidNumberPlace(temp))
{
return(false);
}
temp.cells[row, column] = value;
}
}
}
return(true);
}
public static bool CheckMinimality(Grid grid)
{
Grid temp = (Grid)grid.Clone();
for (int row = 0; row < temp.CellsInRow; row++)
{
for (int column = 0; column < temp.CellsInRow; column++)
{
if (temp.cells[row, column] != 0)
{
int value = temp.cells[row, column];
temp.cells[row, column] = 0;
if (ValidNumberPlace(temp))
{
return false;
}
temp.cells[row, column] = value;
}
}
}
return true;
}
/// <summary>
/// Solve given sudoku grid and solutions upto maximum number specified
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public static IList Solve(Grid grid, int maxSolutions)
{
ArrayList solutions = new ArrayList();
// If grid is solved then return as solution
if (grid.CountFilledCells() == (grid.CellsInRow * grid.CellsInRow))
{
solutions.Add(grid.Clone());
return(solutions);
}
// Solve singles
//Singles(grid);
// Choose unsolved cell
int leastCandidatesRow = -1;
int leastCandidatesColumn = -1;
IList leastCandidates = null;
for (int row = 0; row < grid.CellsInRow; row++)
{
for (int column = 0; column < grid.CellsInRow; column++)
{
if (grid.cells[row, column] == 0)
{
IList candidates = grid.Possibilities(row, column);
// If cell has no possible value then grid is not solvable so quit now
if (candidates.Count == 0)
{
return(solutions);
}
else if (leastCandidates == null || leastCandidates.Count > candidates.Count)
{
leastCandidatesRow = row;
leastCandidatesColumn = column;
leastCandidates = candidates;
}
}
}
}
// For all candidates of unsolved cell
if (leastCandidates != null)
{
while (leastCandidates.Count > 0)
{
// Set candidate
int candidateIndex = random.Next(leastCandidates.Count);
grid.cells[leastCandidatesRow, leastCandidatesColumn] = (int)leastCandidates[candidateIndex];
leastCandidates.RemoveAt(candidateIndex);
Grid nextLevelGrid = (Grid)grid.Clone();
IList nextLevelSolutions = Solve(nextLevelGrid, maxSolutions);
solutions.AddRange(nextLevelSolutions);
// Trim number of solutions so we don't exceed maximum required
if (solutions.Count > maxSolutions)
{
solutions.RemoveRange(0, solutions.Count - maxSolutions);
}
if (solutions.Count == maxSolutions)
{
return(solutions);
}
}
}
return(solutions);
}
/// <summary>
/// rate a grid
/// returns it as int
/// the lower the harder
/// </summary>
/// <param name="grid">Grid</param>
/// <returns></returns>
public static int Rate(Grid gridOrg)
{
Grid grid = (Grid)gridOrg.Clone();
int rate = 0;
rateAll = 0;
// for(int trys = 0; trys<10;trys++)
// {
// grid = (Grid)gridOrg.Clone();
// rate = 0;
while (grid.CountFilledCells() < (grid.CellsInRow * grid.CellsInRow))
{
int cand = FindUniqueCandidates(grid);
rate += cand;
if (cand > 0)
{
int candidateIndex = random.Next(cand);
int m = -1, i = 0, j = 0, candidateRow = 0, candidateCol = 0;
for (i = 0; i < 9 && m < candidateIndex; i++)
{
for (j = 0; j < 9 && m < candidateIndex; j++)
{
if (grid.uniqueCandidates[i, j] != 0)
{
m++;
if (m == candidateIndex)
{
candidateRow = i;
candidateCol = j;
}
}
}
}
grid.cells[candidateRow, candidateCol] = grid.uniqueCandidates[candidateRow, candidateCol];
}
else
{
//rate = rate - ((grid.BlocksAcross * grid.BlocksAcross) - grid.CountFilledCells());
//no more unique cells -> difficult grid
rate = grid.CountFilledCells();
break;
}
}
// rateAll += rate;
// MediaPortal.GUI.Library.Log.WriteFile(MediaPortal.GUI.Library.LogType.Log, "Soduko Rate end "+trys+" notes: {0}", rate);
// }
return rate;
}
/// <summary>
/// Solve given sudoku grid and solutions upto maximum number specified
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public static IList Solve(Grid grid, int maxSolutions)
{
ArrayList solutions = new ArrayList();
// If grid is solved then return as solution
if (grid.CountFilledCells() == (grid.CellsInRow * grid.CellsInRow))
{
solutions.Add(grid.Clone());
return solutions;
}
// Solve singles
//Singles(grid);
// Choose unsolved cell
int leastCandidatesRow = -1;
int leastCandidatesColumn = -1;
IList leastCandidates = null;
for (int row = 0; row < grid.CellsInRow; row++)
{
for (int column = 0; column < grid.CellsInRow; column++)
{
if (grid.cells[row, column] == 0)
{
IList candidates = grid.Possibilities(row, column);
// If cell has no possible value then grid is not solvable so quit now
if (candidates.Count == 0)
{
return solutions;
}
else if (leastCandidates == null || leastCandidates.Count > candidates.Count)
{
leastCandidatesRow = row;
leastCandidatesColumn = column;
leastCandidates = candidates;
}
}
}
}
// For all candidates of unsolved cell
if (leastCandidates != null)
{
while (leastCandidates.Count > 0)
{
// Set candidate
int candidateIndex = random.Next(leastCandidates.Count);
grid.cells[leastCandidatesRow, leastCandidatesColumn] = (int)leastCandidates[candidateIndex];
leastCandidates.RemoveAt(candidateIndex);
Grid nextLevelGrid = (Grid)grid.Clone();
IList nextLevelSolutions = Solve(nextLevelGrid, maxSolutions);
solutions.AddRange(nextLevelSolutions);
// Trim number of solutions so we don't exceed maximum required
if (solutions.Count > maxSolutions)
{
solutions.RemoveRange(0, solutions.Count - maxSolutions);
}
if (solutions.Count == maxSolutions)
{
return solutions;
}
}
}
return solutions;
}