/// <summary>
/// Solves a sudoku board.
/// </summary>
/// <param name="board">The board to solve.</param>
/// <param name="index">The zero-based index up to 99.</param>
/// <returns>True if the board was solved.</returns>
private static bool Solve(SudokuBoard board, int index)
{
if (index == 9 * 9)
{
return(true);
}
SudokuSquare square = board.Squares[index / 9];
int inSquareIndex = index % 9;
for (int i = 1; i <= 9; i++)
{
square.Values[inSquareIndex] = i;
if (board.IsValid(index))
{
bool solved = SudokuSolver.Solve(board, index + 1);
if (solved)
{
return(true);
}
}
}
square.Values[inSquareIndex] = 0;
return(false);
}
public static SudokuResult Solve(string puzzle)
{
puzzle = puzzle.Replace('.', '0');
var puzzleArray = puzzle.ToCharArray().Select(e => e - '0').ToArray();
var grid = new List <SudokuSquare>();
int row = 0;
int col = 0;
// loop through every square
for (int i = 0; i < puzzle.Length; i++)
{
var square = new SudokuSquare(col, row, puzzleArray[i]);
grid.Add(square);
col++;
if (col > 8)
{
row++;
col = 0;
}
}
var gridArray = grid.ToArray();
if (TrySolve(gridArray))
{
return(new SudokuResult
{
Solved = true,
Puzzle = string.Join("", gridArray.Select(e => e.Value))
});
}
;
return(new SudokuResult());
}
public bool IsValid(int index)
{
SudokuSquare square = this.Squares[index / 9];
int inSquareIndex = index % 9;
int value = square.Values[inSquareIndex];
if (!square.IsValidValue(inSquareIndex, value))
{
return(false);
}
return(this.IsValidValueInRowAndColumn(index, value));
}
public void SwitchValueTest()
{
SudokuSquare square1 = new SudokuSquare(0, 0, 0);
SudokuSquare square2 = new SudokuSquare(0, 1, 0);
square1.ValueSet += square2.RemovePossibleValue;
square1.ValueUnset += square2.AddPossibleValue;
square2.ValueSet += square1.RemovePossibleValue;
square2.ValueUnset += square1.AddPossibleValue;
square1.Value = 3;
Assert.IsFalse(square2.PossibleValues.Contains(3));
square1.Value = 4;
Assert.IsTrue(square2.PossibleValues.Contains(3));
Assert.IsFalse(square2.PossibleValues.Contains(4));
}
public void MultipleValueSwitchTest()
{
SudokuSquare[] squares = new SudokuSquare[9];
for(int i = 0; i < 9; i++)
{
squares[i] = new SudokuSquare(0, 0, 0);
}
foreach (var square in squares)
{
var otherSquares = from s in squares
where s != square
select s;
foreach (var otherSquare in otherSquares)
{
square.ValueSet += otherSquare.RemovePossibleValue;
square.ValueUnset += otherSquare.AddPossibleValue;
}
}
squares[0].Value = 4;
squares[1].Value = 9;
squares[2].Value = 8;
squares[3].Value = 6;
squares[4].Value = 1;
squares[5].Value = 2;
squares[6].Value = 3;
squares[7].Value = 7;
squares[8].Value = 5;
squares[8].Value = 6;
squares[5].Value = 9;
squares[3].Value = null;
squares[1].Value = null;
Assert.IsTrue(squares[3].PossibleValues.Contains(2));
Assert.IsTrue(squares[3].PossibleValues.Contains(5));
Assert.IsTrue(squares[1].PossibleValues.Contains(2));
Assert.IsTrue(squares[1].PossibleValues.Contains(5));
squares[3].Value = 5;
Assert.AreEqual(2, squares[1].Value);
}
void InsertRandomN()
{
for (int i = 0; i < board.Length; i++)
{
for (int j = 0; j < board[i].Length; j++)
{
counter++;
var obj = Instantiate(Cell, new Vector3(i * 2f, j * 2f), Quaternion.identity) as GameObject;
obj.transform.parent = gameObject.transform;
sudokuSquare = obj.GetComponent<SudokuSquare>();
if (sudokuSquare)
{
sudokuSquare.correctNum = faceValues[i][j];
sudokuSquare.ID = counter;
}
else
Debug.Log("help");
}
}
}
void InsertRandomN()
{
for (int i = 0; i < board.Length; i++)
{
for (int j = 0; j < board[i].Length; j++)
{
counter++;
var obj = Instantiate(Cell, new Vector3(i * 2f, j * 2f), Quaternion.identity) as GameObject;
obj.transform.parent = gameObject.transform;
sudokuSquare = obj.GetComponent <SudokuSquare>();
if (sudokuSquare)
{
sudokuSquare.correctNum = faceValues[i][j];
sudokuSquare.ID = counter;
}
else
{
Debug.Log("help");
}
}
}
}
public void UnsetEventTest()
{
SudokuSquare square1 = new SudokuSquare(0, 0, 0);
SudokuSquare square2 = new SudokuSquare(0, 1, 0);
SudokuSquare square3 = new SudokuSquare(0, 2, 0);
square1.ValueSet += square2.RemovePossibleValue;
square1.ValueSet += square3.RemovePossibleValue;
square1.ValueUnset += square2.AddPossibleValue;
square1.ValueUnset += square3.AddPossibleValue;
square2.ValueSet += square1.RemovePossibleValue;
square2.ValueSet += square3.RemovePossibleValue;
square2.ValueUnset += square1.AddPossibleValue;
square2.ValueUnset += square3.AddPossibleValue;
square3.ValueSet += square2.RemovePossibleValue;
square3.ValueSet += square1.RemovePossibleValue;
square3.ValueUnset += square2.AddPossibleValue;
square3.ValueUnset += square1.AddPossibleValue;
square1.Value = 3;
Assert.IsFalse(square2.PossibleValues.Contains(3));
Assert.IsFalse(square3.PossibleValues.Contains(3));
square2.Value = 4;
Assert.IsFalse(square3.PossibleValues.Contains(4));
square1.Value = null;
Assert.IsTrue(square3.PossibleValues.Contains(3));
Assert.IsFalse(square1.PossibleValues.Contains(4));
square2.Value = null;
Assert.IsTrue(square3.PossibleValues.Contains(4));
Assert.IsTrue(square1.PossibleValues.Contains(4));
Assert.IsTrue(square2.PossibleValues.Contains(3));
}