public void SolvesSudokus()
{
SudokuPuzzle unsolved = SudokuPuzzle.CreateFromStream(GetStreamFromFileName(GOODSINGLEPUZZLEFILE));
//One more time!
SudokuPuzzle unsolved2 = SudokuPuzzle.CreateFromStream(GetStreamFromFileName(GOODSINGLEPUZZLEFILE));
Assert.IsFalse(unsolved.IsSolved());
SudokuPuzzle solved = new SudokuPuzzle("Solved1")
{
PuzzleMatrix = new int[][]
{
new int[] { 4, 8, 3, 9, 2, 1, 6, 5, 7 },
new int[] { 9, 6, 7, 3, 4, 5, 8, 2, 1 },
new int[] { 2, 5, 1, 8, 7, 6, 4, 9, 3 },
new int[] { 5, 4, 8, 1, 3, 2, 9, 7, 6 },
new int[] { 7, 2, 9, 5, 6, 4, 1, 3, 8 },
new int[] { 1, 3, 6, 7, 9, 8, 2, 4, 5 },
new int[] { 3, 7, 2, 6, 8, 9, 5, 1, 4 },
new int[] { 8, 1, 4, 2, 5, 3, 7, 6, 9 },
new int[] { 6, 9, 5, 4, 1, 7, 3, 8, 2 },
}
};
SudokuRoot totest = new SudokuRoot();
totest.SolveSudoku(unsolved);
totest.SolveSudoku(unsolved2);
Assert.IsTrue(unsolved.IsSolved());
Assert.IsTrue(unsolved2.IsSolved());
}
public void TestPuzzleIsSolved()
{
int dimension = 3;
List <int> cellValues = new List <int>();
// Test a row
for (int i = 0; i < dimension * dimension * dimension * dimension; ++i)
{
cellValues.Add(0);
}
SudokuPuzzle puzzle = new SudokuPuzzle(dimension, cellValues);
Assert.IsFalse(puzzle.IsSolved());
for (int i = 0; i < puzzle.Rows.Count; ++i)
{
for (int k = 0; k < puzzle.Rows[i].Count; ++k)
{
puzzle.Rows[i][k].RemoveAllExcept(1);
}
}
Assert.IsTrue(puzzle.IsSolved());
}
/// <summary>
/// Solves the given <see cref="SudokuPuzzle"/>
/// </summary>
/// <param name="puzzle">The <see cref="SudokuPuzzle"/> being solved</param>
/// <returns>A list of <see cref="SudokuPuzzle"/>s that are solutions to the given <see cref="SudokuPuzzle"/></returns>
public List <SudokuPuzzle> Solve(SudokuPuzzle puzzle)
{
List <SudokuPuzzle> solutions = new List <SudokuPuzzle>();
Stack <SudokuPuzzle> puzzleStack = new Stack <SudokuPuzzle>();
puzzleStack.Push(puzzle.Clone());
while (puzzleStack.Count > 0)
{
try
{
SudokuPuzzle puzzleToSolve = puzzleStack.Pop();
if (puzzle.IsValid())
{
bool puzzleAdvanced = false;
do
{
puzzleAdvanced = false;
for (int i = 0; i < this.strategies.Count; ++i)
{
while (this.strategies[i].AdvancePuzzle(puzzleToSolve))
{
puzzleAdvanced = true;
}
}
}while (puzzleAdvanced);
if (puzzleToSolve.IsSolved() && puzzleToSolve.IsValid())
{
solutions.Add(puzzleToSolve);
if (solutions.Count > 1)
{
break;
}
}
else
{
foreach (SudokuPuzzle guess in this.Guess(puzzleToSolve))
{
puzzleStack.Push(guess);
}
}
}
}
catch (Exception)
{
}
}
return(solutions);
}
private bool SolvePuzzle(SudokuPuzzle sudokuPuzzle)
{
if (sudokuPuzzle.IsSolved())
{
return(true);
}
var unsolvedCells = sudokuPuzzle.Cells.OfType <Cell>().Where(x => !x.HasValue).OrderBy(x => x.CanBe.Count).ToArray();
// for each cell
foreach (var cell in unsolvedCells)
{
var row = sudokuPuzzle.Rows[cell.RowIndex];
var column = sudokuPuzzle.Columns[cell.ColumnIndex];
var blockIndex = sudokuPuzzle.GetBlockIndex(cell);
var block = sudokuPuzzle.Blocks[blockIndex.RowIndex, blockIndex.ColumnIndex];
var potentialCellValues = new List <int>(cell.CanBe);
// for each potential value
foreach (var value in potentialCellValues)
{
var usedInRow = row.Cells.Count(x => x.Value == value) > 0;
var usedInColumn = column.Cells.Count(x => x.Value == value) > 0;
var usedInBlock = block.Cells.OfType <Cell>().Count(x => x.Value == value) > 0;
// if potential value already used in row, column or block, skip it
if (usedInRow || usedInColumn || usedInBlock)
{
continue;
}
// try to recursively solve the puzzle
cell.Value = value;
if (SolvePuzzle(sudokuPuzzle))
{
return(true);
}
// if puzzle cannot be solve, revert the value
else
{
cell.Value = 0;
cell.CanBe.AddRange(potentialCellValues);
}
}
return(false);
}
return(false);
}
/// <inheritdoc />
public SudokuPuzzle Solve(int[,] sudoku)
{
var sudokuPuzzle = new SudokuPuzzle(sudoku);
while (!sudokuPuzzle.IsSolved())
{
var solution = SolveSingleStep(sudokuPuzzle);
if (solution == null)
{
// Sudoku cannot be solved :(
sudokuPuzzle = _sudokuPuzzleAfterFailedSolveSingleStep;
break;
}
else
{
sudokuPuzzle.ApplySingleStepSolution(solution);
_sudokuPuzzleAfterFailedSolveSingleStep = sudokuPuzzle;
}
}
return(sudokuPuzzle);
}
public void IsSolvedIsCorrect()
{
SudokuPuzzle unsolved = SudokuPuzzle.CreateFromStream(GetStreamFromFileName(GOODSINGLEPUZZLEFILE));
Assert.IsFalse(unsolved.IsSolved());
SudokuPuzzle solved = new SudokuPuzzle("Solved1")
{
PuzzleMatrix = new int[][]
{
new int[] { 4, 8, 3, 9, 2, 1, 6, 5, 7 },
new int[] { 9, 6, 7, 3, 4, 5, 8, 2, 1 },
new int[] { 2, 5, 1, 8, 7, 6, 4, 9, 3 },
new int[] { 5, 4, 8, 1, 3, 2, 9, 7, 6 },
new int[] { 7, 2, 9, 5, 6, 4, 1, 3, 8 },
new int[] { 1, 3, 6, 7, 9, 8, 2, 4, 5 },
new int[] { 3, 7, 2, 6, 8, 9, 5, 1, 4 },
new int[] { 8, 1, 4, 2, 5, 3, 7, 6, 9 },
new int[] { 6, 9, 5, 4, 1, 7, 3, 8, 2 },
}
};
Assert.IsTrue(solved.IsSolved());
}
/// <inheritdoc />
public SingleStepSolution SolveSingleStep(SudokuPuzzle sudokuPuzzle)
{
if (sudokuPuzzle.IsSolved())
{
return(null);
}
foreach (var strategy in _strategies)
{
var elimination = _basicElimination.SolveSingleStep(sudokuPuzzle);
if (elimination != null)
{
return(elimination);
}
var solution = strategy.SolveSingleStep(sudokuPuzzle);
if (solution != null)
{
return(solution);
}
}
return(null);
}
