private static List<int> FindSingularizedCells(SudokuPuzzle puzzle1, SudokuPuzzle puzzle2, int cellIndex)
{
return
puzzle1.Peers(cellIndex)
.Where(i => puzzle1.Cells[i].Length > 1 && puzzle2.Cells[i].Length == 1)
.ToList();
}
public object Clone()
{
var clone = new SudokuPuzzle(Length) { Cells = new int[Cells.Length][] };
for (var i = 0; i < Cells.Length; i++)
{
clone.Cells[i] = new int[Cells[i].Length];
Buffer.BlockCopy(Cells[i], 0, clone.Cells[i], 0, Buffer.ByteLength(Cells[i]));
}
return clone;
}
public static SudokuPuzzle RandomGrid(int size)
{
var puzzle = new SudokuPuzzle(size);
while (true)
{
var unsolvedCellIndexes = puzzle.Cells
.Select((cands, index) => new { cands, index })
.Where(t => t.cands.Length >= 2)
.Select(u => u.index)
.ToArray();
var cellIndex = unsolvedCellIndexes[Random.Next(unsolvedCellIndexes.Length)];
var candidateValue = puzzle.Cells[cellIndex][Random.Next(puzzle.Cells[cellIndex].Length)];
var workingPuzzle = puzzle.PlaceValue(cellIndex, candidateValue);
if (workingPuzzle == null) continue;
var solutions = MultiSolve(workingPuzzle, 2);
switch (solutions.Count)
{
case 0:
continue;
case 1:
return solutions.Single();
default:
puzzle = workingPuzzle;
break;
}
}
}
private 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;
}
