public static SudokuPuzzle generatePuzzle(int size)
{
SudokuPuzzle puzzle = new SudokuPuzzle(size);
var rand = new Random();
while (true)
{
int[] UnsolvedCellIndexes = puzzle.Cells
.Select((cands, index) => new { cands, index }) //Project to a new sequence of candidates and index (an anonymous type behaving like a tuple)
.Where(t => t.cands.Length >= 2) //Filter to cells with at least 2 candidates
.Select(u => u.index) //Project the tuple to only the index
.ToArray();
int cellIndex = UnsolvedCellIndexes[rand.Next(UnsolvedCellIndexes.Length)];
int candidateValue = puzzle.Cells[cellIndex][rand.Next(puzzle.Cells[cellIndex].Length)];
SudokuPuzzle workingPuzzle = puzzle.PlaceValue(cellIndex, candidateValue);
if (workingPuzzle != null)
{
var Solutions = MultiSolve(workingPuzzle, 2);
switch (Solutions.Count)
{
case 0: continue;
case 1: return(Solutions.Single());
default:
puzzle = workingPuzzle;
break;
}
}
}
}
public static List <SudokuPuzzle> MultiSolve(SudokuPuzzle input, int MaximumSolutions = -1)
{
var Solutions = new List <SudokuPuzzle>();
input.Solve(p =>
{
Solutions.Add(p);
return(Solutions.Count() < MaximumSolutions || MaximumSolutions == -1);
});
return(Solutions);
}
public virtual object Clone()
{
var clone = new SudokuPuzzle(this.Length);
clone.Cells = new int[this.Cells.Length][];
for (int i = 0; i < this.Cells.Length; i++)
{
clone.Cells[i] = new int[this.Cells[i].Length];
Buffer.BlockCopy(this.Cells[i], 0, clone.Cells[i], 0, Buffer.ByteLength(this.Cells[i]));
}
return(clone);
}
public static List <int> FindSingularizedCells(SudokuPuzzle puzzle1, SudokuPuzzle puzzle2, int cellIndex)
{
Debug.Assert(puzzle1.Length == puzzle2.Length);
var result = new List <int>();
foreach (int i in puzzle1.Peers(cellIndex))
{
if (puzzle1.Cells[i].Length > 1 && puzzle2.Cells[i].Length == 1)
{
result.Add(i);
}
}
return(result);
}
private void generateButton_Click(object sender, EventArgs e)
{
generateButton.IsAccessible = false;
String origText = generateButton.Text;
generateButton.Text = "Getting your sudoku, stay put";
Sudoku.DifficultyLevel diffLevel = (Sudoku.DifficultyLevel)diffLevelComboBox.SelectedValue;
SudokuPuzzle generator = SudokuPuzzle.generatePuzzle(9);
sudoku = generator.getSudoku(diffLevel);
solvedSudoku = generator.getSudoku(Sudoku.DifficultyLevel.None);
sudokuBoardViewController.updateBoardView(sudoku);
generateButton.IsAccessible = true;
generateButton.Text = origText;
}
public static int[] CreateClues(SudokuPuzzle input, int maxClues = 0)
{
//Get a unique solution for the input puzzle, in case it wasn't already
var puzzle = input.Solve();
if (puzzle == null)
{
throw new ArgumentException("Can't create clues from an unsolvable puzzle!");
}
//This is the list of clues we work on. It can be reconstituted into a new puzzle object by way of a constructor
int[] Clues = puzzle.Cells.Select(c => c[0]).ToArray();
var rand = new Random();
while (true)
{
//Pick a random cell to blank
int ClueCell = rand.Next(Clues.Length);
if (Clues[ClueCell] == 0)
{
continue;
}
var workingClues = Clues.ToArray();
workingClues[ClueCell] = 0;
if (MultiSolve(new SudokuPuzzle(workingClues), 2).Count() > 1)
{
if (maxClues == 0)
{
return(Clues);
}
else
{
continue;
}
}
Clues = workingClues;
if (Clues.Count(c => c != 0) <= maxClues)
{
return(Clues);
}
}
}
public virtual SudokuPuzzle ApplyConstraints(int cellIndex, int value)
{
SudokuPuzzle puzzle = (SudokuPuzzle)this.Clone();
//Standard Sudoku constraint logic: Set this cell to one and only one candidate, and remove this value from the candidate list of all its peers
puzzle.Cells[cellIndex] = new int[] { value };
foreach (int peerIndex in puzzle.Peers(cellIndex))
{
var newPeers = puzzle.Cells[peerIndex].Except(new int[] { value }).ToArray();
if (!newPeers.Any())
{
return(null);
}
puzzle.Cells[peerIndex] = newPeers;
}
return(puzzle);
}
public static void Output(SudokuPuzzle puzzle)
{
System.Console.Write(puzzle.ToString());
}
